No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Evidence of the possibility of natural reciprocal crosses between Pinus sylvestris and P. uliginosa based on the phenology of reproductive organs
Abstract
Phenological observations of development of generative organs of Pinus sylvestris and P. uliginosa (= P. rotundata) were carried out in spring of 1999, 2000 and 2001. The aim of the research was to verify the hypothesis that both taxa have a possibility of reciprocal crossing. Two populations of P. uliginosa were tested, one on the Silesian Lowland (Węgliniec) (altitude of 180m), the other in the Stołowe mountains (Batorów) (at altitude of 750 m). The lowland population of P. uliginosa is not numerous and surrounded by extensive P. sylvestris forests, the mountain one is 3 times more numerous, and the nearest population of P.sylvestris is at a distance of 2 km. Observations in the field were carried out twice a week during the period of development of micro- and macro-strobili of both taxa. The results show that the P. sylvestris strobili developed every year earlier than those of P. uliginosa. Nevertheless, this did not eliminate the possibility of cross pollination and gene flow from P. sylvestris toward P. uliginosa on both localities of the last species. The possibility of pollination of P. sylvestris macrostrobili by P. uliginosa pollen was found also possible, but more restricted. Normally, on lowlands the same phenological phases take place about 10 days earlier than in the mountains. This is documented for two years of observations of more or less typical whether conditions. An earlier development of micro- and macrostrobili of both species in their mountain populations was observed in an observation year characterized by an extremely early and warm spring.
... Nagy et al. [28] proposed the theory of the altitude-related biological phenomenon, which has had negative effects on plant communities reducing the number of plant species [29], the plant productivity [30], the organ size trends [31], the physiology and morphology of plants [32], the gene ecology [33] and the characteristics of the history of life [34]. In addition, Friend and Woodward [35] and Nagy [28] showed that the physical factors such as tree growth, altitude, decrease of air temperature with altitude, influence of exposition, solar radiation, access to the light, atmospheric pressure, increased precipitation, and wind speed affect plant development. e only studies published over the past decade on the taxonomic and geographical differentiation of conifers show that morphological and anatomical characteristics of needles are important in the recognition of phylogenetic relationships and geographic pattern of variation in Pinaceae [14,[35][36][37][38][39]. ...
... In addition, Friend and Woodward [35] and Nagy [28] showed that the physical factors such as tree growth, altitude, decrease of air temperature with altitude, influence of exposition, solar radiation, access to the light, atmospheric pressure, increased precipitation, and wind speed affect plant development. e only studies published over the past decade on the taxonomic and geographical differentiation of conifers show that morphological and anatomical characteristics of needles are important in the recognition of phylogenetic relationships and geographic pattern of variation in Pinaceae [14,[35][36][37][38][39]. In Morocco and in Algeria, some morphological traits have been used as criteria for differentiating species and trees in nurseries and natural populations [40,41]. ...
The study of morphological and anatomical characteristics of leaves is important for assessing the geographical variation of species. The ecological adaptability of forty individuals from four populations of Cedrus atlantica were studied, based on analysis of morphological and anatomical traits. The results of the Spearman nonparametric coefficient of correlation showed that the number of stomatal lines (NLS) and the length of the needle (NL) are negatively correlated to altitude and positively to latitude and precipitation sums, while the width of the needle (NW), the thickness of the cuticle (CT), and the number of needles per rosette (NN/R) were negatively related to temperature. In addition, the sum of precipitation is negatively correlated with NW. The first two principal components account for 58.18% of the variation. According to Tukey’s test and Kruskal–Wallis test, all populations had at least three characters separating them at a statistically significant variation. Moreover, the hierarchical classification led us to the individualization of three main groups. All these results show an adaptation of the structure of the needles of C. atlantica from Morocco to the geographical position and the climatic conditions of the populations.
... However, due to extrazonal occurrence, these species meet on several places of northern Slovakia where they may intercross sporadically. According to Boratyński et al. (2003), there is a 10-day shift in phenology of P. mugo reproductive organs compared to those of P. sylvestris in the region. This shift does not prevent crosspollination and gene flow from P. sylvestris towards P. mugo and, to some extent, also reciprocally. ...
... Our phenological observations ruled out the lack of pollination due to asynchronous flowering causing reduced seed setting. Only slight differences in the flowering periods of the two species have also been revealed by Boratyński et al. (2003) based on morphology of the reproductive organs in P. sylvestris and P. uliginosa. Striking differences in germination percentage of seeds from control populations P. mugo and P. sylvestris on the one hand and putative hybrid swarms on the other hand may be taken as an indirect evidence supporting the hybrid nature of the swarms. ...
Generally acknowledged reduction of the interspecific hybrid fertility was utilized in evaluation of the putative hybrid swarms of Scots pine (Pinus sylvestris L.) and mountain dwarf pine (P. mugo Turra) viability under field conditions. Pollen viability and seed quality of the trees from the four contact zones of P. sylvestris and P. mugo in Slovakia were compared with the corresponding characteristics of the pure populations of these species from three reference localities. Pollen germination percentage was comparable in contact zones and control populations of the species. Statistically significant differences between the parent and hybrid groups were detected in pollen tube length only. In general, pollen tubes of the pure species populations were longer than those in contact zones. At the cone level, the individuals from contact zones possessed shorter cones than the trees of pure species populations P. mugo and P. sylvestris. This was paralleled by a lower number of seeds per cone in contact zones and higher amount of seeds per cone in the P. mugo population. Striking differences between individuals of the contact zones and reference populations were revealed also in germination potentials of their seeds. Significantly higher proportions of germinating seeds was found in the reference populations of P. mugo and P. sylvestris than in their contact zones. Contrary to seed quality parameters mentioned above, the fractions of filled but non-germinating seeds and amounts of empty seeds were higher in contact zones than in the parental species populations, indicating higher frequency occurrence of abortive embryogenesis in the former. The lower fertility characteristics of the individuals from contact zones indicate their hybrid nature.
... We evaluated relationships between populations to assess the possibility of potential past plant stock transfers. As P. uliginosa populations are exposed to potential gene flow from other pines including P. mugo and P. sylvestris (Boratyñska et al. 2003; Boratyñski et al. 2003; Lewandowski et al. 2005), we evaluated the possibility of the species decline due to genetic pollution and contamination of P. uliginosa gene pool. We also evaluated the genetic structure of P. uliginosa seeds derived from two stands that can potentially serve as a genetic material for reintroduction . ...
... Natural hybridisation in sympatric populations of the taxa from P. mugo complex and P. sylvestris was suggested in biometric (B¹czkiewicz 1995; Bobowicz 1990) and biochemical studies (Prus-G³owacki and Szweykowski 1979, 1983, Siedlewska 1994; Siedlewska and Prus-G³owacki 1995). The phenological observations supported the possibility of interspecific crosspollinations indicating the overlapping periods of pollen perception by P. uliginosa and pollen release by P. sylvestris (Boratyñski et al. 2003). Our two populations from Low Silesian Pinewood are surrounded by extensive forest stand of P. sylvestris and the population from Batorów Reserve is also not totally isolated from the influence of foreign pollen from the nearest Scots pine populations. ...
Recent changes in environmental conditions in populations of peat-bog pine (Pinus uliginosa Neumann) caused rapid decline or even extinction of the species in several stands in Central Europe. Conservation strategies for P. uliginosa require information about the evolutionary history and genetic structure of its populations. Using isozymes we assessed the genetic structure of P. uliginosa from four isolated stands in Poland and compared the results to genetic structures of other closely related pine species including eight populations of Pinus mugo, ten of Pinus sylvestris and one of Pinus uncinata. The level of genetic variability of P. uliginosa measured by the mean number of alleles per locus and average heterozygosity was similar to others related to P. uliginosa taxa from the reference group but it differs among populations. High genetic similarity was found between two populations of P. uliginosa from Low Silesian Pinewood. The populations were genetically distinct as compared to other populations including locus classicus of the species from the peat bog at Batorów Reserve. Very low genetic distance (DN = 0.002) and small genetic differentiation (GST = 0.003) were found between P. uliginosa and P. mugo in the sympatric populations of the species from Zieleniec peat bog suggesting the ongoing natural hybridisation and genetic contamination of peat-bog pine from this area. Some evidence for skew in allele frequency distribution potentially due to recent bottleneck was found in population from Low Silesian Pinewood. The analysed open pollinated progeny derived from two P. uliginosa stands from Low Silesian Pinewood showed the excess of homozygotes as compared to the maternal trees indicating high level of inbreeding (F = 0.105, F = 0.081). The results are discussed in the context of evolution of P. uliginosa populations, taxonomic relationships between the analysed species and conservation strategies for active protection of peat-bog pine.
... In other studies, Huang et al. [57] and Nikolić et al. [58] found a significant percentage variation in the width and the height of the needle between natural populations of P. yunnanensis in Southwest China and P. peuce in Montenegro and Serbia, respectively. On the contrary, Boratyński et al. [59] and Boratyńska et al. [54] have found that the width of needle does not always distinguish between different pairs of populations of P. mugo and Pinus sylvestris at a significant level, or between P. uliginosa and P. sylvestris. In the same sense, Urbaniak et al. [60] reported that neither width of needle (Nw) nor height of needle (Nh) or Nh/Nw distinguish between the P. sylvestris populations in the Tatra Mountains. ...
Atlas cedar (Cedrus atlantica (Endl.) G. Manetti ex Carrière) is an endemic species in the mountains of North Africa that is attracting international interest in its use in the reforestation of degraded ecosystems. is study aims to investigate and evaluate the morphoanatomical characteristics of needles of four cedar populations localized in the Middle and High Atlas Mountains. Descriptive statistics, analysis of variance (ANOVA), descriptive power, scatter-plot of the discrimination function, scatter-plot of discrimination, and dendrogram of the closest Euclidean distances were made on traits. e results of the linear model of ANOVA nested as population and tree within population suggest the differences statistically significant for the traits measured at a different level. Among these traits, the length of the needle, the width of a vascular bundle including endodermis, and thickness of the wall of hypodermis cell revealed the highest discriminating characters among populations of C. atlantica from the Middle and High Atlas and between the populations of the Middle Atlas. e agglomeration of populations over short Euclidean distances also showed a higher level of differentiation between two ecotypes of C. atlantica not very geographically distant in the Atlas Mountains of Morocco. e ecotype belonging to Aït Oufella and Aït Ayach confers this species a place of choice in the projects of revalorization of the Mediterranean populations, especially in semiarid areas.
... Hybridization and introgression are important evolutionary factors that increase species variation and may lead to speciation [1][2][3][4][5][6]. These two processes concern mostly related species, which do not express isolation mechanisms such as phenological barriers [7] and post-pollination barriers to fertilization [8]. The interbreeding between different species of Pinaceae was found to be quite frequent [9][10][11][12]. ...
Scots pine (Pinus sylvestris L.) and the taxa from the P. mugo complex can hybridize in the contact zones and produce fertile hybrids. A unique example of an early Holocene relict population of P. sylvestris and P. uliginosa (a taxon from the P. mugo complex) growing on the tops of Jurassic sandstone rocks is located in Błędne Skały (Sudetes). Phenotypically, there are trees resembling P. sylvestris, P. uliginosa and intermediate forms between them. We expected that some of P. sylvestris and/or P. uliginosa-like trees could be in fact cryptic hybrids resembling one of the parental phenotypes. To address this question, we examined randomly sampled individuals, using a set of plastid (cpDNA), nuclear (nDNA) and mitochondrial (mtDNA) markers as well as biometric characteristics of needles and cones. The results were compared to the same measurements of allopatric reference populations of the P. sylvestris and the P. mugo complex (Pinus mugo s.s, P. uncinata and P. uliginosa). We detected cpDNA barcodes of the P. mugo complex in most individuals with the P. sylvestris phenotype, while we did not detect cpDNA diagnostic of P. sylvestris within P. uliginosa-like trees. These results indicate the presence of cryptic hybrids of the P. sylvestris phenotype. We found only three typical P. sylvestris individuals that were clustered with the species reference populations based on needle and cone characteristics. Most trees showed intermediate characteristics between P. sylvestris and P. uliginosa-like trees, indicating intensive and probably long-lasting hybridization of the taxa at this area and subsequent gene erosion of parental species.
... Formation of the putative natural P. mugo 9 P. sylvestris hybrids was first reported based on morphology (Marcet 1967;Christensen 1987a, b;Christensen and Dar 1997;Boratyński et al. 2003;Danusevičius et al. 2012) and confirmed by DNA markers (Kormutak et al. 2008;Wachowiak and Prus-Głowacki 2008). Kormutak et al. (2008) assessed the hybridization rates in the seeds with the cpDNA markers to define the species of the male parent in the seed embryo and the species of the female parent in the gametophyte carrying only the maternal genome. ...
The aim of this study was to elucidate the introduction history of P. mugo in the unique landscape of the Lithuanian seaside spit of Kursiu Nerija by assessing its genetic structure and the genetic diversity. The individuals were sampled in 12 populations within an area of 3 km × 50 km along the Lithuanian part of Kursiu Nerija. P. mugo was introduced over 200 years ago to prevent sand erosion by establishing a forest cover. Chloroplast DNA polymorphism of 220 individuals of P. mugo together with 18 P. sylvestris and 11 putative P. sylvestris × P. mugo hybrids was assessed by the aid of five microsatellite markers. The standard intra-population diversity indexes were calculated. The intra-specific variation between distinct morphotypes as well as the population differentiation within the most spread P. mugo ssp. rotundata morphotype was assessed based on the haplotype frequencies by hierarchical AMOVA, GST/RST test, UPGMA clustering and PCA methods. The genetic diversity of P. mugo in Kursiu Nerija was high (He = 0.95; 83 different haplotypes). All except one of the P. mugo populations sampled contained a notable share of private haplotypes. AMOVA revealed high intra-specific diversity but low differentiation between the P. mugo populations. Most of the haplotypic variance was within populations. The UPGMA clustering produced groups more corresponding to the sub-species morphotypes than the geography of the populations. There was no geographical pattern of reduction in genetic diversity towards the younger plantations. A strong candidate for a species-specific DNA marker was found. After several events of introduction, the genetic diversity of P. mugo in Kursiu Nerija is very high and is structured based on the sub-species morphotypes rather than geography. The high frequency of shared and notable frequency of private haplotypes in most of the populations indicate that the major part of the P. mugo material originates from a number of geographically and genetically related sources, which more likely are introductions from abroad that the local collections. The high frequency of private haplotypes in the northernmost populations leaves a possibility for minor introductions from other genetically distinct sources. The absence of private haplotypes in one of the sampled populations indicates the use of local seed collections. The large number of shared haplotypes provides a strong evidence for a geneflow among the P. mugo taxa.
... In order to prove their hybrid nature, some populations were characterized in detail using needle morphology and anatomy (Staszkiewicz 1996;Christensen and Dar 1997;Bobowicz et al. 2000), needle proteins and isozymes (Prus-Glowacki and Szweykowski 1980;Prus-Glowacki et al. 1981;Filppula et al. 1992). As far as the reproductive behavior is concerned, the phenology of reproductive organs was followed indicating gene flow from Pinus sylvestris to Pinus uliginosa and to some extent reciprocally (Boratyński et al. 2003). Seed quality has also been taken into account but in the artificial hybrids of Pinus montana 9 Pinus sylvestris only. ...
Comparative study on fertilization process in Pinus sylvestris, Pinus mugo and in their putative hybrid swarm individuals was done involving pre-zygotic and post-zygotic stages. The amount of surviving
ovules from open pollination reflecting the mode of interaction between pollen grains and nucellar tissue of an ovule averaged
at 8.1 of sound ovules per conelet in Pinus sylvestris, 7.3 ovules in the hybrid swarm population and at 4.9 ovules in Pinus mugo. A strong correlation was observed between the number of surviving ovules and the proportion of germinating seeds in the compared
species and hybrids. Normal course of embryogenesis in Pinus sylvestris and Pinus mugo contrasted with increased frequency of disturbances observed in the hybrid swarm individuals. The differential survival rates
of the ovules and deviations from typical pattern of embryogenesis are discussed from the standpoint of cross-ability relationship
between Pinus sylvestris and Pinus mugo.
... However, the isoenzymes (Lewandowski et al. 2002) and cpDNA analyses (Wachowiak et al. 2000; Wachowiak et al. 2005a, b) showed that the hybrids occurrence is rather restricted . The examinations of the plastid and mitochondrial DNA, paternally and motherly inherited, respectively, confirm only one way of the gene flow, from taxa of P. mugo complex to P. sylvestris (Wachowiak and Prus-Głowacki 2008 ), in spite of the possibility of the reverse pollination (Boratyński et al. 2003). Thank to that, the existence of isolated small populations of P. uliginosa, retaining the morphological characteristics of the taxa, is possible, as it is observed in the Węgliniec and Węglowiec, which are surrounded by the extensive forests of P. sylvestris (Lewandowski et al. 2002; Boratyńska et al. 2003; Wachowiak et al. 2005a; Kormut'ák at al. 2005). ...
Pinus uliginosa is an interesting taxon from the Pinus mugo complex with controversial systematic
position andspecific characteristics, intermediate among P. mugo, P. uncinata and P. sylvestris. The peat-bog
pine is rare andprotectedin Poland. All its’ known populations have a relict character andare slightly different
from each other. The aim of the present study was comparison of the individuals from the Czarne Bagno of the “Torfowisko pod Zieleńcem” Nature Reserve (Sudetes), determined in the field on the basis of morphological characteristics as Pinus uliginosa, with four samples of this taxon from the northern limits of its range in PolandandGermany andwith Pinus sylvestris, P. mugo and P. uncinata, to verify morphological andtaxonomic relations between them. The material collected from 30 individuals determined as P. uliginosa, was closest to populations of P. uliginosa from the Bory Dolnośląskie, andto P. mugo from the Tatra Mts., concerning the needle characters. The cone characteristics of P. uliginosa individuals from the Czarne Bagno appeared similar to all other of that taxon. In spite of that, the cone characters first of all differentiate P. uliginosa from P. sylvestris, P. mugo and P. uncinata. The combination of needle and cone morphological characters are a good tool to distinguish P. sylvestris, P. uncinata, P. mugo and P. uliginosa with a very high probability.
... P. sylvestris and P. mugo are taxonomically close and according to [17] belong to the section Pinus, subsection Sylvestres Loud. In agreement with [18], flowering synchronization (P. sylvestris dispersing pollen earlier) between the two pine species in Nerija should not be a strong factor preventing hybridization because of (a) large microsite variation (dunes) creating warmer and colder niches, which cause large variation in flowering time among trees during one season (our observation, not presented here), and (b) the transfer effect of P. sylvestris introduced from various parts of Lithuania and may be Germany causing large variation in timing of flowering [19, 20]. ...
We address the problem of spontaneous hybridization between an exotic species Pinus mugo and the native/local P. sylvestris at the seaside spit of Kursiu Nerija in Lithuania. The objective was to identify spontaneous hybrids between P. mugo and P. sylvestris based on morphology traits among the individuals naturally regenerating at the seaside spit. The field inventory was carried out over the entire Lithuanian part of the spit, and 200 individuals morphologically intermediate between P. sylvestris and P. mugo were identified. Based on a weighted trait index, the intermediate individuals were grouped into two groups, one morphologically close to P. sylvestris and another close to P. mugo. The needle micromorphological traits of the putative hybrids were of intermediate values between P. mugo and P. sylvestris. The results provide a strong evidence of spontaneous hybridization between P. mugo and P. sylvestris in Lithuanian seaside spit of Kursiu Nerija.
Pinus sylvestris (Scots pine) and taxa from the P. mugo (mountain pine) complex hybridize in contact zones producing morphologically-intermediate fertile hybrids. However, the hybrid specimens sometimes express only the P. sylvestris phenotype. Such cryptic hybrids were detected among P. sylvestris and P. uliginosa in the western part of Błędne Skały in the Stołowe Mountains, where the pines grow on the tops of sandstone rocks and phenotypically resemble P. sylvestris, P. uliginosa, and P. mugo. Hybrids with the P. sylvestris phenotype could be potentially present in other relic populations of this species in these mountains. During the present study, the hybrids were identified only in the area of Błędne Skały based on chloroplast and mitochondrial markers, morphological differentiation of various needle and cone traits, and phenotype assessments of the trees during sampling. ese hybrids included three cryptic hybrids of P. sylvestris × P. mugo with the P. sylvestris phenotype and one displaying the phenotype of P. uliginosa. e other populations analyzed represented Scots pine with no evidence of hybridization with P. uliginosa and/or P. mugo. Biometric data on the cone and needle morphology also suggest possible hybridization within the P. mugo complex on Błędne Skały. e results indicate that hybridization takes place in this population but not in neighboring populations despite the possible connection by pollen-mediated gene flow.
La phase de renouvellement constitue l’étape clé de la transmission du patrimoine génétique d’un peuplement forestier et du maintien de sa diversité génétique. Son succès est conditionné par la production de pollen et de graines. Cette thèse s’intéresse à l’impact de la structure des peuplements reproducteurs à différentes échelles spatiales sur les flux de gènes lors de régénérations naturelles de pin sylvestre (Pinus sylvestris L.). Elle identifie les principaux déterminants de la production quantitative et qualitative de graines à l’échelle d’un peuplement. Nos résultats démontrent la nécessité de prendre en compte, à l’échelle d’un massif forestier, le caractère isolé ou non de l’unité de gestion à régénérer pour évaluer son potentiel fructifère. Dans des peuplements isolés, une production réduite de pollen peut ainsi conduire à une diminution de la production de graines viables et donc à une limitation de la population de semis naturels. Ce phénomène est accru quand les reproducteurs sont eux-mêmes isolés au sein d’un peuplement mélangé chêne-pin. Dans de larges massifs au contraire, la plupart des événements de fécondation sont issus d’un nuage pollinique suffisamment abondant pour ne pas limiter la production de graines. Dans ce cas les échanges polliniques dépassent l’échelle de l’unité de gestion. Il en résulte une faible différenciation des nuages polliniques captés par les différents arbres-mères. Enfin, nos travaux montrent que la dispersion des graines est concentrée dans le temps et se produit majoritairement à moins de 50m des semenciers. Nos résultats sont discutés dans le cadre de la gestion courante des massifs forestiers pour limiter les risques génétiques liés à certaines pratiques sylvicoles. Nous proposons enfin des descripteurs de terrain des principaux déterminants de la production et de la dispersion des graines en vue d’assurer le succès de la régénération naturelle.
The high mountain plants of Central and Southern Europe survived the glacial periods in the same mountain ridges, but at lower altitudes and possibly covering larger areas than during interglacials. This implies a high level of species differentiation between isolated mountain ridges. Pinus mugo complex, which includes P. mugo s.s. (Alps, Sudetes, Carpathians, Dynaric Alps, and Rhodopes), P. uncinata (Pyrenees and Alps), and P. uliginosa (Sudetes and neighbouring mountain ridges) is a good group to examine such a scenario. We screened 44 populations across the geographic range of the complex, using 10 cpSSR markers to study (1) taxonomic relations among P. mugo s.s., P. uncinata, and P. uliginosa and (2) genetic and phylogeographic structure in P. mugo s.s. and P. uncinata. Allelic combinations of 87 size variants produced a total of 757 haplotypes. Haplotypic diversity was high and similar in every species (0.997, 0.986 and 0.991, respectively). The highest divergence between haplotypes was observed in P. uliginosa (
= 10.29). The AMOVA revealed that most of the overall genetic variation is explained by the within-population component (FST = 0.121, RST = 0.206) and by the geography (FCT = 0.056, RCT = 0.083). The differentiation between P. mugo s.s., P. uncinata, and P. uliginosa is explained by about 5% (P<0.001) of the total variation. Vicariant gene pools for the complex were identified in the Pyrenees, the Alps with the Tatra Mts, the Sudetes, and the East and South Carpathians along with the Balkan Mountains. The phylogeographic structure was observed in P. mugo s.l., P. mugo s.s., and P. uncinata. Results support the separate taxonomic status of P. uncinata and P. mugo s.s. and possible hybrid origin of P. uliginosa.
A putative interspecific hybridization in Pinaceae family was investigated. Very rarely the physiological methods were involved in hybridization processes that occurs in the hybrid zones. It is well known that in most gymnosperms, the plastid genome is inherited from the paternal component while the mitochondrion is inherited from the maternal one. Therefore functioning pattern of organelles in the hybrid plant can suggest parent, from which they were inherited. The aim of this study was to indirectly establish the inheritance energy-transducing organelles (mitochondria, chloroplast) according to their functioning. Current year needles from Siberian Stone Pine (Pinus sibirica Du Tour) and Japanese Stone Pine (Pinus pumila (Pall.) Regel) as parent species and their putative hybrids were collected from Baikal Region. The photosynthesis rate was determined by using the spectrophotometer. The study of emission CO2 under dark respiration of needle was conducted with laser optical-acoustic gasanalyzer. The quantity was measured at 1, 2 and 3 hour after experiment start. The rate of the photoreduction ferricyanide potassium was characterized by the primary photochemical processes activity at the level of photosystem II. Comparison of pure species was shown that Japanese Stone Pine had higher functional activity of chloroplast as compared with SiberianStone Pine in spite of the fact that they are growing in similar environment conditions. Two of three analyzed hybrids had decreasedactivity of their chloroplasts. Unfortunately, in this case we can't conclude if the chloroplasts were inherited from Siberian Stone Pine orfrom Japanese Stone Pine. Chloroplast activity of the third hybrid was approximately similar to that of Japanese Stone Pine suggesting thatits chloroplasts were inherited from this parent. Consequently, the Siberian Stone Pine and the Japanese Stone Pine were maternal and paternal, respectively parents of the hybrid. Compared to the Siberian Stone Pine, the Japanese Stone Pine had higher dark respiration rate.The hybrid respiration rate was similar to that of the Japanese Stone Pine suggesting that the hybrid inherited mitochondria from thisspecies. Our findings indicated that the P. pumila exhibited particular ecological plasticity and this phenomenon is attributable to its high potential activity of photosynthetic and respiratory processes. These physiological features explained the large transcontinental naturalhabitat of Japanese Stone Pine.
Artificial hybridization experiments revealed a relatively high degree of crossability between Pinus sylvestris and P. mugo, ranging between 0.15 and 0.98. Differences between P. sylvestris x P. mugo and reciprocal hybrids of the species were observed. Hybrid seeds of P. sylvestris x P. mugo shared higher germination potential than seeds from selfing, controlled intraspecific crossing, and open pollination. The corresponding value in reciprocal combination was slightly lower. The hybrid nature of the seeds obtained was shown by restriction analysis of chloroplast DNA (cpDNA) using the trnV-trnH/Hinf I primer-enzyme combination.
The results of morphological and anatomical studies on Pinus uliginosa needles from newly-discovered localities of this species in We{ogonek}glowiec (Bory Dolnośla{ogonek}skie) are presented. The data obtained were compared to similar published material on P. uliginosa needles from its loco classico in Batorów and from the lowland locality in We{ogonek}gliniec Nature Reserve, and to P. sylvestris growing nearby. In terms of needle structure, all three P. uliginosa populations were slightly different. The samples analyzed differed markedly from the sample of P. sylvestris, which contradicts the hypothesis that Scots pine has had a significant influence on the gene pool of P. uliginosa.
The phenotypic differentiation of Pinus mugo complex was verified using 31 populations of P. mugo sensu stricto, 11 of P. uncinata, five of P. uliginosa, one of the potential hybrids P. uliginosa × P. mugo and three of P. sylvestris, the latter as a control. The 22 morphological and anatomical needle characteristics were measured and statistically examined to describe the taxa and the population within the taxa differentiation. All the taxa of the P. mugo complex differed significantly from P. sylvestris in most of the verified needle characteristics. Within P. mugo complex, populations of P. uncinata were clearly distinguished from P. mugo s. s. The population of potential hybrid origin was the most similar to P. uliginosa. Populations of the latter taxon were strongly differentiated; some of them were closer to P. uncinata, and others to P. mugo s. s. Within the whole sampled data, three geographic groups of populations were detected: the first included P. uncinata and two of P. uliginosa, the second contained East and South Carpathian P. mugo s. s. with the presumed hybrid population, and the third contained all the other populations of P. mugo s. s. and P. uliginosa. Within P. mugo s. s., the Sudetan populations formed a separate group. Pinus uncinata from the Pyrenees reflected a high level of differentiation. The marginal populations of this taxon (Cebollera, Gúdar, Massif Central) also differed from those in the Pyrenees. The phenotypic differentiation of taxa and populations appeared similar to that which was detected based on cpDNA markers.
Results of artificial fertilization of P. uliginosa with P. sylvestris and P. mugo are presented and discussed. P. sylvestris and P. mugo are thought to be the parental species of P. uliginosa. Two grafts of one P. uliginosa clone from Arboretum of the Institute of Dendrology in Kórnik, Poland were used as mother individuals. One individual of P. sylvestris and one individual of P. mugo were the pollen donors. Three mature cones were obtained as the result of artificial pollination of P. uliginosa with P. mugo pollen. Out of 107 seeds, 68 were filled what gives 63%. P. uliginosa conelets pollinated with P. sylvestris pollen were all aborted. Based on obtained data, close phylogenetic relationship between P. uliginosa and P. mugo complex is suggested.
Molecular evidence for spontaneous hybridization between Pinus sylvestris L. and P. mugo Turra in the putative hybrid swarm populations of the species in Slovakia was provided based on PCR-RFLP analysis of the cpDNA trnV-trnH region. Species-specific restriction profiles generated by Hinf I digests of the cpDNA products reliably identified P. sylvestris and P. mugo haplotypes of the embryos from open pollination. Simultaneous analysis of the respective cpDNA region in megagametophytes and embryos of individual seeds along with needles of a given maternal tree has enabled to score either the P. sylvestris or P. mugo haplotypes in the embryos illustrating hybridization patterns between the two species. Data obtained in this way indicate a relatively extensive hybridization which takes place between P. sylvestris and P. mugo. The extent of hybridization varied among populations as evidenced by the 41.1-58.7% proportion of hybrid embryos registered on the locality Habovka, and by the 8.3% and 2.7% proportions of hybrid embryos on the localities Tisovnica and Sucha Hora, respectively. The approach itself is recommended as a convenient method for monitoring the hybridization patterns in sympatric zones of the studied pine species.
Selected names in the genus Pinus are analyzed. Neotype of the name P. uncinata var. pseudopumilio Willk. is replaced by a lectotype (PR). The name P. uliginosa Neumann in Wimm. is shown to be the correct donor of the epithet for the bog pine at the rank of subspecies and a new combination is proposed [P. uncinata Ramond ex DC. subsp. uliginosa (Neumann) Businský comb. nova]; the taxonomic conclusions are mainly based on the studies of Polish authors on this taxon. The name P. hartenbergiensis Liebich is analysed; a neotype is selected from the locus classicus population in W. Bohemia. The name is correct for the bog pine at the rank of species. The name P. rotundata Link was published as early as 1827, its neotype is shown to be in full accordance with the protologue. A field study of the neotype population shows that the name does not represent a hybrid or intermediate between P. mugo and P. unicinata, nor it can be used for the bog pine. It represents intermediates between P. uncinata subsp. uncinata and subsp. uliginosa, closer to the former taxon. The name P. obliqua Reichenb. was neotypified in conflict with the protologue; therefore a new neotype is selected and the name again represents intermediates between P. uncinata subsp. uncinata and subsp. uliginosa, closer to the former taxon.
The objective was to identify spontaneous hybrids between P. mugo and P. sylvestris using organelle DNA markers in sympatric zones at the sea-side spit of Kursiu Nerija in western Lithuania. A field inventory was carried out over the entire Lithuanian part of the spit and 203 individuals morphologically intermediate between P. sylvestris and P. mugo were tested for their male parent with chloroplast DNA PCR-RFLP markers and for their female parent with mitochondrial DNA PCR markers. Unfortunately, the mitochondrial DNA Nad7 marker failed to identify the female parent species in our study. However, the chloroplast DNA PCR-RFLP marker revealed that out of 203 tested individuals only 23 had a paternity different than that indicated by morphology. Of these, 13 individuals were morphologically identified as P. sylvestris but possessed cpDNA of P. mugo (putative hybrids with P. sylvestris (female) ×P. mugo (male parent), and 10 individuals morphologically identified as P. mugo possessed cpDNA of P. sylvestris and may be hybrids with P. mugo (female) ×P. sylvestris (male parent). The remainder of the 177 individuals identified in the field inventory were were considered as pure species. In conclusion, our study indicates ongoing spontaneous hybridization between P. mugo and P. syvestris in Kursiu Nerija. Human impact via seed transfer on altered hybridization rates as well as evolutionary consequences are discussed.
The purpose of the present study was to test the taxonomic value of sclerenchyma in distinguishing Pinus sylvestris and P. mugo, P. uncinata, P. rotundata and P. uliginosa, all representing the subsection Sylvestres within the genus Pinus. Thirty-six samples were gathered in natural populations. Every sample was represented with 30 individuals, every individual with 10 brachyblasts. Three types of sclerenchymatic cells surrounding the resin canals and four between vascular bundles were distinguished. Relations among samples and taxa were verified using discriminant analysis and clustering based on Euclidean distances. The types of sclerenchymatic cells surrounding the resin canals and located between the vascular bundles differentiate the compared taxa when used as average frequencies but are extremely variable and do not allow the classification of every individual. The study demonstrated that the type of sclerenchymatic cells surrounding the resin canals and between the vascular bundles in needles could have an important taxonomic value in distinguishing the taxa of two-needle pines of the subsection Sylvestres in Europe at the population level. The distinguishing of individuals was difficult because of very high variation of sclerenchyma characters.
Bog pine (Pinus uncinata DC. subsp. uliginosa (Neumann) Businský) is a subendemic species and appears to be one of the most endangered tree species of the Czech Republic. Its rare populations are at the present time greatly endangered namely by spontaneous hybridization with the Scots pine (Pinus sylvestris L.). Regarding the fact that its protection is insufficient even in national nature reserves (NNR) and the classical propagation by cuttings is problematic, modern methods were adopted for a long-term preservation of the taxon. Growth regulation conditions were investigated for the induction of organogenesis and somatic embryogenesis. Mature seeds were obtained from selected trees in the Žofinka NNR and from a locality near the village of Krajková in the Sokolov district. Cotyledon and hypocotyl segments from seedlings pregerminated in sterile conditions were used to induce the organogenesis. Bud proliferation was observed on the cotyledons after 4 weeks. The largest amount of buds was found on the medium with 1.5 mg.l−1 benzyladenine (BA) and 0.5 mg.l−1 1-naphtylacetic acid (NAA) after 12 weeks. The hypocotyl segments showed only the formation of green callus. Isolated mature zygotic embryos were used for the induction of somatic embryogenesis. Development of mucilaginous callus was recorded after 3 weeks of cultivation on media with different combinations of BA, NAA and 2,4-dichlorophenoxy acetic acid (2,4-D) concentrations. When the callus induced on the medium with the combination of 0.56 (1.13) mg.l−1 BA and 1.86 mg.l−1 NAA was transferred on the medium with lower BA (0.113 mg.l−1) and 2,4-D (0.44 mg.l−1) concentrations, the first somatic embryos started to emerge after a period of other two weeks.
Pinus uncinata subsp. uliginosa, seeds, in vitro germination, organogenesis, somatic embryogenesis
We tested the performance of molecular markers and biometric traits in the identification of hybrids between closely related mountain pine (Pinus uncinata) and Scots pine (Pinus sylvestris). A plastid DNA marker and a set of morphological and anatomical needle traits were applied in analyses of individuals from several sympatric stands of the species and a single-species' population from southern Europe, used as a reference. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) marker from the plastid trnL–trnF region and morphological and anatomical traits clearly discriminated between the pure species. Significant differences were found between P. uncinata and P. sylvestris, mostly in the shape of epidermal cells and the number of stomata. Four putative hybrids with P. sylvestris morphology, but with P. uncinata plastid DNA haplotypes, were found in a population from Sierra de Gúdar near Valdelinares, the southernmost locality of the latter species in eastern Spain. Discrimination analyses between and within populations placed these individuals on the edge of an agglomeration of P. sylvestris individuals. The results suggest that hybridization between the species is rare, but can result in cryptic hybrids morphologically similar to the maternal species. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163, 473–485.
Thirty-three individuals of Pinus mugo from the Abruzzian Apennines (Italy), the most isolated population of the species, were examined biometrically to verify the range of trait variation and compared with six other populations sampled in the north-eastern part of the species range. Ten needles and ten cones from each individual were measured and quantified on the basis of 31 traits. The interpopulation comparison revealed a close affinity of the Abruzzian population of P. mugo to three of the six other populations. The other three north-eastern populations, one from the Tatra Mountains and two from the Chornokhora Mountains, appeared to be different. This suggests that these populations originated from other Pleistocene centres of occurrence. The intrapopulation variation of the population from the Abruzzian Apennines is comparable with those of all six populations of P. mugo from the Sudety and Carpathian Mountains. These findings support the hypothesis that isolated but locally abundant plant populations do not necessarily show a reduction in variability resulting from isolation. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 147, 309–316.
Peat-bog pine Pinus uliginosa Neumann has become extinct or rare in many parts of Europe. It is supposed to hybridize with P. sylvestris but the influence of hybridization to genetic erosion of the P. uliginosa gene pool is unknown. In the presented study, the crossability between P. uliginosa and P. sylvestris was analyzed in a sympatric population at Węgliniec reserve in Poland. The aim of the study was to prove natural hybridisation and to estimate the influence of this phenomenon on possible natural gene pool erosion of peat-bog pine. A sequence polymorphism in the trnF–trnL cpDNA region of P. uliginosa and P. sylvestris was used to develop the species diagnostic PCR-RFLP marker. The marker of paternally transmitted cpDNA was applied in haplotype analyses of the progeny from open-pollinated P. uliginosa seeds (collected in 2000–2002) and from P. sylvestris ones (in 2002). An inconsistency in species diagnostic cpDNA haplotypes of seedlings and parental trees was observable both for P. uliginosa and P. sylvestris (about 1% and 2% of hybrids seeds, respectively). The results prove the occurrence of reciprocal hybridisation between the species. The influence of hybridisation on the natural gene pool protection and measures to reintroduce peat-bog pine is discussed.
Natural hybridisation was postulated between the closely related pine species Pinus sylvestris and the P. mugo complex, however no clear evidence on propagation of mature hybrids in nature has been documented so far. To test the hybridisation
hypothesis we applied chloroplast DNA (cpDNA) markers and isozymes in the analyses of 300 individuals representing the variety of morphological forms in the sympatric
populations of P. sylvestris, P. mugo and P. uliginosa at the peat bog complex in the Sudety Mts., Poland. Additionally, the haplotypes of paternally inherited cpDNA of 149 open pollinated progeny derived from seeds were compared to the haplotypes of parental trees to access the intensity
and direction of contemporary hybridisation. The morphologically highly variable polycormic (multi-stemmed) hybrids between
P. mugo and P. uliginosa were identified. The second group of hybrids was found among the monocormic (single-stemmed) P. sylvestris-like individuals carrying the cpDNA from P. mugo complex. Hybrids of P. sylvestris as a pollen donor and P. mugo or P. uliginosa as a mother were not found, either in the group of examined trees, or among the open pollinated progeny. The results indicate
that numerous hybrids can exist in the sympatric population of the species studied and that gene flow can successfully proceed
from P. mugo complex to P. sylvestris. Hybridisation and ecological selection seems to play a significant role in diversification and evolution of the investigated
species.
Eight natural populations of Pinus uncinata Ramond from the Spanish Pyrenees, five of P. mugo Turra from the Carpathians, the Sudethians and Abruzzian Apennines, three of P. sylvestris L. from the Central-European Lowland and the Iberian Peninsula and one of P. uliginosa Neumann from SW Poland have been compared biometrically in 16 cone characters. P. uncinata appears the most distant from all other taxa, differing by having the largest and most asymmetric cones and the thickest
apophyses with the most prominent umbo. In cone characters, P. mugo is more similar to P. sylvestris than to P. uncinata. Nevertheless, P. mugo and P. sylvestris remain distant from each other in a number of morphological characters examined. P. uliginosa has cones intermediate between the other three taxa and is moreover very variable. The locality of P. uliginosa in the Silesian Lowland may be of a relict character and conserve genes from P. uncinata.
Crop characteristics involving cone size, average number of seeds per cone, and seed germinability have been studied for three
hybrid swarm populations of Pinus mugo and P. sylvestris, two pure P. mugo populations and one pure P. sylvestris population, in northern Slovakia. Generally, reproduction capability characteristics were significantly reduced in hybrid
swarms in relation to the control populations. Although there were no consistent differences between hybrid swarms and control
populations in the average number of seeds per cone or cone size, seed germination rates and full seed production in hybrid
swarms were lower than for the control population of P. sylvestris and one of the pure populations of P. mugo. Based on these data a conclusion has been drawn postulating partial rather than full fertility of the hybrid swarm populations
of P. mugo and P. sylvestris.
Differences in morphological and anatomical characters of needles between seedlings, saplings and adult trees of the endangered Pinus uliginosa from the Węgliniec Nature Reserve in SW Poland were examined biometrically and statistically assessed using the Student's t-test, Tukey–Kramer test, step-wise discrimination and agglomeration on Euclidean distances according to Ward's method. Pinus sylvestris adults and seedlings were used as comparative material. The results show that needles of all three P. uliginosa generations differ significantly from each other. In seedling needles, several anatomical characters were similar to those of P. sylvestris growing in the vicinity of the reserve. However, P. uliginosa had a lower number of resin canals, lower frequency of fibre-like sclerenchyma cells and higher frequency of thin-walled sclerenchyma cells with large lumens in the spaces between vascular bundles. Needle characters of saplings and adult trees of both species were distinctly more different than it was the case in the seedling stage.
PCR-RFLP technique has been used to detect species-specific mutations of organelles DNA for closely related dwarf mountain pine (Pinus mugo) and Scots pine (P. sylvestris). Restriction fragment patterns have been compared of amplification products for trnL-trnF cpDNA and for cox1 and orf25 genes of mtDNA. The difference has been found in the Dral and HinfI restriction patterns of the amplification products for trnL-trnF region of cpDNA with two haplotypes detected. The haplotype M is characteristic for P. mugo and the haplotype S for P. sylvestris. These markers may be useful for the analysis of the natural hybridisation and introgression between these species postulated for some sympatric populations on the basis of morphological analysis. No differences have been disclosed in the studied mtDNA regions.
Studies on taxonomic position of Pinus uliginosa Neumann, P. uncinata Ram. and P. mugo Turra, indicate a significant specificity of P. uliginosa population from Wielkie Torfowisko Batorowskie Peat Bog. Pinus uncinata in respect of genetic similarity is close to Pinus mugo Turra populations from the Tatra Mts. The time of divergence of P. uliginosa from the common ancestor, taking into account Nei's genetic distances, is twice as long as in the case of Pinus uncinata. In the view of the results the supposition that Pinus uliginosa from Wielkie Torfowisko Batorowskie Peat Bog is a marginal population of P. uncinata can be excluded, because of their significant difference in genetic structure. The presumable reasons of specificity of P. uliginosa population are disscused.
Isoenzyme variability of eight groups of individuals from different parts of putative hybrid swarm population (P. mugo Turra x P. sylvestris L.) from "Torfowisko Zieleniec" peat-bog complex was studied at ten enzymatic loci. Differences in allelic frequencies distribution among particular samples of the Zieleniec population were statistically significant at 9 loci, as shown by G2- statistics. Chi-square test indicated that in each of studied subpopulations frequencies of alleles at some loci (2-5) differed significantly from frequencies expected for a homogeneous population. Heterozygosity values and also a genotypic polymorphism in studied population confirmed the existence of large genetic variation. Wright's fixation indices (F) showed some excess of homozygotes in majority studied groups of individuals, notably higher in some subpopulations. Gene diversity coefficient for 8 subpopulations was high (GST=9.4%). However, when MDH C locus was excluded from the calculation, its value decreased to 2.8%. Presented data demonstrated notable differentiation of subpopulations within studied pine population, comparable with the differentiation among different populations of coniferous species.
In eight natural European populations of four closely related taxa of pines (Pinus sylvestris, P. mugo, P. uncinata, andP. uliginosa) starch-gel electrophoreses revealed altogether 58 alleles at 15 loci from nine enzyme systems. With Nei's genetic distance (D) the largest mean genetic distance (D = 0.171) was found betweenP. sylvestris andP. mugo, a distance corresponding to that between other closely related pine species. Mean genetic distances between the other taxa were less than half that value and characteristic for subspecies or varieties rather than for species. On the basis of our results we suggest that both,P. uliginosa andP. uncinata, could be the result of the ancient hybridization betweenP. sylvestris andP. mugo.
Clonal variation in flowering characteristics and cone production was investigated in a Scots pine (Pinus sylvestris L) clonal seed orchard consisting of 32 clones. At the time of observations, the orchard was 17-19 years old. It was found that on average, within a clone, female flowers were receptive about 1 day before the beginning of pollen shedding and there was a significant correlation between the ranks of clones according to their onset of flowering in 2 consecutive years. Male and female flowering periods were synchronized among the majority of clones and the index of phenological overlap was over 0.41. Significant variations among clones were found for male and female cone production as well as for some selected pollen-related characteristics. On average, individual clones in the orchard produced in total from 0.4 to 4.5 kg of pollen and from 900 to 6500 cones a year. It was found that 25% and 50% of clones produced 46% and 72% of pollen, respectively. Analogous numbers for cone production were 35% and 63%. Some patterns of sexual asymmetry among clones were detected; however, genetic correlations between pollen and cone productions were positive. Effective population sizes were generally high, but the estimate was lower for pollen (75.9%) than for cone production (95.9%). The expected outcrossing rate, based on effective population size calculated using both male and female contribution and background pollination, was high (0.977). The efficiency of the orchard and its potential use for reforestation purposes is discussed.
Scanning electron microscopy was used to examine some aspects of the pollination mechanism in the selected conifers: Pinus sylvestris L., Firms mugo Turra, Picea abies (L.) Karst, and Abies alba Mill. There were small blisters found on the outer wall of the surface cells of the micropylar lobes of Pinus sylvestris, Pinus mugo and Picea abies at the time of the maximal receptivity of the micropyle. According to our observations, these blisters could capture the pollen grains.
The flavonic profile of Peatbog pines Pinus uliginosa Neumann from Poland and France (with low quercetin content) are close to that of Mugo pine P. mugo Turr. and Mountain pine P. uncinata Ram.; in this respect, the two latter species are indistinguishable. However, the presence of some individuals of sylvestris type (with high quercetin content) is notable; moreover, trees with intermediate quercetin contents can be numerous, revealing a hybridization process in good accordance with Hardy-Weinberg's rule. Foliar morphometry (fineness index: L/P) tends toward the uncinata/mugo type. If specific status is to be conferred to Peatbog pine, it should be admitted that it results from the persistance in this biotope of past crossbreeding between Mountain/Mugo pine and Scots pine (more precisely its chemomorph T-, taxifolin absent), with the second taxon subordinated to the first. A comparison is made with current hybridization and introgression processes at high altitudes, which lead to the Bouget pine Pinus bougeti Flous from the same parent species.
Pinus sylvestris and P. mugo populations from Poland and Czechoslovakia were compared using genetic variability at isozyme markers, chloroplast DNA variation, and mating system measurements. Two isozyme loci were found to differ between the species. P. mugo was as variable at isozyme loci as P. sylvestris. Diagnostic cpDNA fragments were found using the restriction enzyme Bcl-I. Populations that were morphologically classified as hybrids were found to be pure species, based both on isozyme and cpDNA results.
Hybridization among Pinus mugo and P.sylvestris is visualized in Wells' distance diagrams using either equally or differently weighted characters. Parents and hybrids are better resolved in diagrams using differently weighted characters. Putative hybrids from mixed, planted or naturalized stands of P. mugo and P. sylvestris in SW and NW Jutland, Denmark, are compared with artificial F1 and spontaneous material of P. mugo × sylvestris (P. × rhaetica) from the Alps and the Pyrenees. The natural hybrids are primary hybrids, rather than introgressants.
The Pinus mugo complex is revised, and a new infraspecific classification of the species is proposed. The species is divided into two subspecies and an intermediate nothossp., viz. ssp. mugo, ssp. uncinata and nothossp. rotundata. P. mugo ssp. mugo is divided into f. mugo and f. applanata comb, et stat. nov. (P. pumilio) and P. mugo nothossp. rotundata into f. rotundata and f, mughioides comb. nov. The putative hybrid P. mugo × sylvestris found in mixed stands of the parents is named P. × rhaetica. A description of P. sylvestris and a key to P. mugo, P. sylvestris and P. × rhaetica is given.
Flowering phenology and flowering frequencies were investigated in clones of Swedish and Finnish origin growing in a pine seed orchard at Långtora (lat 59°43´, long. 17°08`, alt. 15 m). One purpose was to estimate the gene contribution of individual clones to the progeny. The frequencies of female and male strobili were estimated in 1973-1975. The onset and duration of both female receptivity and pollen dispersal were recorded. The pollen density in the seed orchard was estimated. Great clonal variation prevailed in the seed orchard with respect to the frequency of female and male flowering as well as the onset and duration of female receptivity and pollen dispersal. A good agreement in flowering frequencies and phenological characteristics of the clones between different years was observed. The great vaiation in onset and duration of receptivity and pollen dispersal from year to year was influenced to a great extent by the prevailing temperature conditions in the spring, different years. The calculations of the genetic composition of the progeny revealed that the gene contribution of the analysed clones varied considerably. This was mainly due to differences in the frequency of flowering.
Kilka uwag o sośnie błotnej Pinus uliginosa
- Staszkiewicz
Staszkiewicz, J. (1985): Kilka uwag o sośnie błotnej Pinus uliginosa. – Chrońmy Przyr. Ojczystą 41(5): 56–61.
Research on the seed crop of Scots pine(Pinus silvestris L.) Eskisehir-Catacik forest region
- M Boydak
Boydak, M. (1977): Research on the seed crop of Scots pine (Pinus silvestris L.) Eskisehir-Catacik forest region. – PhD Thesis, Istanbul Universitesi, Orman Fakültesi Yayin 230: 1–193.
Sosna błotna (Pinus uliginosa Neumann) w rezerwacie Błędne Skały w Górach Stołowych
- Boratyński
Boratyn, A. (1978): Sosna błotna (Pinus uliginosa Neu-mann) w rezerwacie Błe ˛ dne Skały w Górach Stołowych. – Arbor. Kórnickie 23: 261–267.
Pinus x rhaetica Brügger Polish plant red data book
- J Staszkiewicz
Staszkiewicz, J. (1993). Pinus x rhaetica Brügger. In: Zar-zycki, K. & Kaz, R. (eds.). Polish plant red data book. – Polish Acad. Sci., Inst. Bot. and Inst. Nature Conserv., Kraków. 38–39.
Analiza fenologii kwitnienia szczepów sosny zwyczajnej (Pinus silvestris L.) na plantacji nasiennej w Siemianicach
- Wesoly
Wesoly, W. (1982): Analiza fenologii kwitnienia szczepów sosny zwyczajnej (Pinus silvestris L.) na plantacji nasien-nej w Siemianicach. – Roczniki AR w Poznaniu, 140: 149–159.
Fizjologia kwitnienia i obradzania
- Chałupka
ChaŁupka, W. (1993): Fizjologia kwitnienia i obradzania. In: BiaŁobok S.; Boratyn A. & BugaŁa W. (eds.). Bio-FLORA (2003) 198
Vascular plants of Poland – a checklist. – Polish Bot. Studies, Guidebook Ser
- Z Mirek
- H Pie¸koś-Mirkowa
- A Zając
- M Zając
Mirek, Z.; PiE¸koś-Mirkowa, H.; ZajĄc, A. & ZajĄc, M. (1995): Vascular plants of Poland – a checklist. – Polish Bot. Studies, Guidebook Ser., 15.
Liczebność i struktura przestrzenna popu-lacji sosny błotnej
- Z Gołąb
GoŁĄb, Z. (1998): Liczebność i struktura przestrzenna popu-lacji sosny błotnej (Pinus uliginosa Neumann) na Wielkim Torfowisku Batorowskim. – National Park of Stołowe Mountains.
Sosna błotna (Pinus uliginosa Neu-mann) w rezerwacie " Torfowisko pod We ˛glin
- K Ambroz ˙y
- Wyd
Ambroz ˙y, K. (1999): Sosna błotna (Pinus uliginosa Neu-mann) w rezerwacie " Torfowisko pod We ˛glin ". Manuscript of MSc thesis, Katedra Botaniki Les AR im. Augusta Cieszkowskiego, Poznań. Bobowicz, M. A. (1990): Mieszańce Pinus mugo Turra × Pinus sylvestris L. z rezerwatu " Bór na Czerwonem ". – Wyd.
Variability of Pinus mugo Turra in Poland IV. Needles and cones in some Polish populations
- Szweykowski
Szweykowski, J. & Bobowicz, M. A. (1983): Variability of Pinus mugo Turra in Poland IV. Needles and cones in some Polish populations. – Bull.
Początek fenologicznych pór roku Narodowy Atlas Polski. Zakład Na-rodowy im Genetic differentiation of Pinus sylvestris and Pinus mugo aggr. populations in Switzer-land
- M Molga
Molga, M. (1974): Początek fenologicznych pór roku. In: Leszczycki S. (ed.). Narodowy Atlas Polski. Zakład Na-rodowy im. Ossolińskich, Wydawnictwo PAN, Wrocław, Warszawa, Kraków, Gdańsk. Map no 34. Neet-Sarqueda, C. (1994): Genetic differentiation of Pinus sylvestris and Pinus mugo aggr. populations in Switzer-land. – Silvae Genetica 43: 207–215.
Figs 5–12 Flowering in a seed orchard of Pinus sylvestris L. – Studia Forestalia Suecica
- K Lännerholm
Lännerholm, K. (1976): Figs 5–12. In: Jonsson, A.;
Ekberg, I. & Eriksson, G. (1976). Flowering in a seed
orchard of Pinus sylvestris L. – Studia Forestalia Suecica
135: 20–21.
Genetic differentiation of Pinus sylvestris and Pinus mugo aggr. populations in Switzerland
- Neet-Sarqueda
Neet-Sarqueda, C. (1994): Genetic differentiation of Pinus
sylvestris and Pinus mugo aggr. populations in Switzerland. – Silvae Genetica 43: 207–215.
Development of megastrobili of Pinus sylvestris (----) and microstrobili of P. uliginosa ( ) at the Stołowe Mts site FLORA
- Fig
Fig. 8. Development of megastrobili of
Pinus sylvestris (----) and microstrobili of P. uliginosa (
) at the Stołowe Mts site
FLORA (2003) 198
Sosna błotna (Pinus uliginosa Neumann) w rezerwacie “Torfowisko pod Węglińcem
- K Ambroży
Flowering in a seed orchard of Pinus sylvestris L.
- Johnsson
Vascular plants of Poland – a checklist
- Mirek
Studies on the effect of mineral fertilization on flowering and cone and seed crops in Scots pine (Pinus sylvestris L.) through an analysis of the litter drop
- Chałupka
Liczebność i struktura przestrzenna populacji sosny błotnej (Pinus uliginosa Neumann) na Wielkim Torfowisku Batorowskim
- Z Gołαb
Poczαtek fenologicznych pór roku
- Molga
Investigations on the flowering and seed crop of Pinus silvestris.
- Sarvas
Pinus x rhaetica Brügger
- Staszkiewicz