Content uploaded by Alan John Lander Phillips
Author content
All content in this area was uploaded by Alan John Lander Phillips
Content may be subject to copyright.
A preview of the PDF is not available
Phylogeny and morphology of Diplodia species on olives in Southern Italy and description of Diplodia olivarum sp. nov.
Abstract and Figures
During a recent study of Botryosphaeria and Neofusicoccum species on olives, a number of Diplodia species were isolated. Most of these were Diplodia seriata while others resembled Diplodia mutila in their hyaline, aseptate, thick-walled conidia. These latter isolates were morphologically (conidial dimensions) and phylogenetically (ITS and EF1-alpha sequences) distinct from other Diplodia species and are described here as Diplodia olivarum sp. nov.
Figures - uploaded by Alan John Lander Phillips
Author content
All figure content in this area was uploaded by Alan John Lander Phillips
Content may be subject to copyright.
... Besides damaging natural ecosystems, Botryosphaeriaceae are important pathogens of many traditional and emerging agricultural crops, such as avocado, fig, grapevine, hazelnut, lemon, loquat, mango, olive, orange, pistachio, pomegranate and walnut (Lazzizera et al., 2008a;Ismail et al., 2013;Carlucci et al., 2015;Linaldeddu et al., 2015aLinaldeddu et al., , 2016bLinaldeddu et al., , 2020aGiambra et al., 2016;Aloi et al., 2021;Aiello et al., 2020Aiello et al., , 2022Gusella et al., 2021Gusella et al., , 2022Gusella et al., , 2023a. Several aggressive species are involved in these pathosystems, including B. dothidea, D. olivarum, L. mediterranea and N. parvum. ...
... Botryosphaeriaceae can also infect native hosts, and then move to other introduced hosts in the same region (Pavlic et al., 2007;Luo et al., 2022). Botryosphaeriaceae are responsible for cankers on host trunks, branches and twigs, dieback and shoot blight, bark cracking, wood discolouration, stemend rots and fruit rots (Carlucci et al., 2015; Aiello et al., 2022Bertetti et al., 2013Carlucci et al., 2013Dardani et al., 2023De Corato et al., 2007Dell'Olmo et al., 2023Dissanayake et al., 2017Fiorenza et al., 2022Garibaldi et al., 2012Grasso and Granata, 2010Gusella et al., 2021Lazzizera et al., 2008bLi et al., 2020Linaldeddu et al., 2009, 2015aMarinelli et al., 2012Martino et al., 2023Moricca et al., 2008Piskur et al., 2011Raimondo et al., 2019Scala et al., 2019Schlegel et al., 2018Spagnolo et al., 2011Turco et al., 2006Wijesinghe et al., 2021Zimowska et al., 2020 Alves et al., 2014Ariyawansa et al., 2015Carlucci et al., 2013Dardani et al., 2023Dissanayake et al., 2017Giambra et al., 2016Lazzizera et al., 2008aLinaldeddu et al., 2006b, 2015a, 2016cLorenzini and Zapparoli, 2018Luchi et al., 2014Martino et al., 2023Mondello et al., 2013Quaglia et al., 2014Raimondo et al., 2019Spagnolo et al., 2011Wijayawardene et al., 2016 (Continued) Aiello et al., 2020Alberti et al., 2018Aloi et al., 2021Bezerra et al., 2021Carlucci et al., 2013Dardani et al., 2023Deidda et al., 2016Dissanayake et al., 2017Faedda et al., 2018Fiorenza et al., 2022Garibaldi et al., 2011Giambra et al., 2016Guarnaccia et al., 2016Gusella et al., 2020a, 2023a, 2023bIsmail et al., 2013Linaldeddu et al., 2007, 2015aLuchi et al., 2014Manca et al., 2020Mang et al., 2022Mondello et al., 2013Moricca et al., 2012Polizzi et al., 2023Raimondo et al., 2019Riccioni et al., 2017Seddaiu et al., 2021Sidoti, 2016Spagnolo et al., 2011 al., 2020, 2022; Gusella et al., 2020aGusella et al., , 2020bGusella et al., , 2021Gusella et al., , 2022Linaldeddu et al., 2020a;Bezerra et al., 2021;Fiorenza et al., , 2023, and these infections are often caused by multiple pathogen genera that may play different roles in infection processes of host plants. ...
... The presence of Botryosphaeriaceae fungi associated with decline of olives in Italy is not well defined, although several studies on olive diseases have reported and described the involvement of some of these fungi. Lazzizera et al., (2008aLazzizera et al., ( , 2008b, during surveys carried out in southern Italy (Apulia and Basilicata regions), isolated many fungi belonging to Botryosphaeriaceae, from rotted olive drupes. These fungi included the new species D. olivarum. ...
Many fungi belonging to Botryosphaeriaceae are well-known as causal agents of diseases in economically and ecologically important agricultural crops and forest trees. In Italy, the high diffusion of Botryosphaeriaceae infections observed over the last decade, has shown the importance of this group of fungi, which are becoming limiting factors for plant production in agricultural systems, nurseries and natural and urban landscapes. Global warming and stress factors such as occasional extreme climatic events can affect the susceptibility of host plants, as well as fungus behaviour, increasing the risk of future infections. Available reports of Botryosphaeriaceae in Italy have been examined, focusing on wood and fruit pathogens, resulting in a list of ten genera and 57 species. Diplodia is the most widespread genus in Italy with 76 records on 44 hosts, while at species level, Neofusicoccum parvum, Botryosphaeria dothidea and Diplodia seriata show the widest host ranges and many records. The ability of the pathogens to remain latent on asymptomatic plants, and uncontrolled trade of plant materials among countries, facilitate the dissemination and potential introduction of new Botryosphaeriaceae species. Preventive detection and adequate control strategies are always needed to limit the potential damage caused by Botryosphaeriaceae. This review had particular emphasis on host-pathogen associations, disease symptoms, geographic distribution, metabolite production, and accurate pathogen identification.
... Species in Diplodia are characterized by hyaline, aseptate and thick-walled conidia that may become pigmented and 1-septate either after or before discharge from the pycnidia . They have a worldwide distribution and are known as pathogens, endophytes and saprophytes on a wide range of mainly woody hosts (Damm et al. 2007, Lazzizera et al. 2008, Laveau et al. 2009, Pérez et al. 2010, Phillips et al. 2012, Linaldeddu et al. 2013, Abdollahzadeh 2015. Some Diplodia species are important pathogens causing cankers, dieback, wilt, root diseases, leaf spots and shoot/tip blight on a variety of horticultural crops, such as D. corticola on oaks, D. sapinea on pines and D. mutila and D. seriata on apples (Alves et al. 2004, Trapman et al. 2008, Stanosz et al. 2009, Phillips et al. 2012, Úrbez-Torres et al. 2016, Ferreira et al. 2021. ...
... In this sense, the narrow host range of Neodeightonia species might be related with their host preference towards bamboos and, particularly, palms, since most of them have been found associated with Arecaceae members. Moreover, host preference has already been shown in many species of Diplodia , Damm et al. 2007, Lazzizera et al. 2008, Úrbez-Torres et al. 2010, Phillips et al. 2012, so it would not be surprising to find a similar pattern of host preference in the closely related genus Neodeightonia. ...
The Botryosphaeriaceae is the largest family in Botryosphaeriales and currently comprises 22 genera of important endophytes, saprobes and plant pathogens. Most botryosphaeriaceous species have a cosmopolitan distribution, occurring on a wide range of woody hosts. Nonetheless, in many hosts, including palms (Arecaceae), the complex of associated Botryosphaeriaceae taxa is as yet unknown. The present study aimed to identify the botryosphaeriaceous species associated with foliar lesions of ornamental palms in Lisbon, Portugal. Twenty-nine Botryosphaeriaceae taxa were isolated from seven different palm species and identified based on both morphological and phylogenetic analyses. Six genera were detected: Botryosphaeria, Diplodia, Dothiorella, Neodeightonia, Neofusicoccum and Sardiniella. A new species of Neodeightonia, N. chamaeropicola, is introduced. Three botryosphaeriaceous species are reduced to synonymy. Thirteen new plant host-fungus associations are reported, while four new geographical records are noted for Portugal. A synopsis of accepted and phylogenetically validated Botryosphaeriaceae taxa reported from palms worldwide is presented. A total of 31 botryosphaeriaceous species have been currently reported from Arecaceae hosts, and many of them are associated with disease symptoms. This illustrates that more systematic studies are needed to examine the complex of Botryosphaeriaceae taxa associated with palms and determine their potential pathogenicity.
... Botryosphaeria dothidea, Diplodia mutila, Dothiorella sarmentorum, Lasiodiplodia theobromae and Neofusicoccum parvum), while other species have narrower host ranges (e. g. Diplodia olivarum was reported on olive, oleaster, carob, grapevine, almond et al.) (Lazzizera et al. 2008;Granata et al. 2011;Linaldeddu et al. 2015;Olmo et al. 2016) or even in very specific hosts (e. g. Eutiarosporella darliae was only reported on infected wheat and wheat-stubble) (Thynne et al. 2015;Farr and Rossman 2021). ...
... Recently, many Botryosphaeriaceae species have been frequently reported on woody oil plants. Diplodia olivarum was first reported from rotting olive drupes in Italy (Lazzizera et al. 2008) and later it was reported as associated with declining Prunus dulcis trees in Spain (Gramaje et al. 2012). Diplodia insularis was isolated from branch canker of Pistacia lentiscus in Italy (Linaldeddu et al. 2015). ...
Woody oil plants are important economic trees which are widely cultivated and distributed throughout China. Surveys conducted during 2020 and 2021 on several woody oil plantations from five regions of Sichuan Province, China, revealed a high diversity of Botryosphaerialean fungi. The identification of 50 botryosphaeriaceous isolates was carried out based on both morphology and multi-gene phylogenetic analysis of internal transcribed spacer region (ITS), translation elongation factor 1-alpha gene ( tef1 ) and β-tubulin gene ( tub2 ). This allowed the identification of twelve previously known Botryosphaeriales species: Aplosporella prunicola , A. ginkgonis , Barriopsis tectonae , Botryosphaeria dothidea , Bo. fabicerciana , Diplodia mutila , Di. seriata , Dothiorella sarmentorum , Neofusicoccum parvum , Sardiniella guizhouensis , Sphaeropsis citrigena , and Sp. guizhouensis , and four novel species belonging to the genera Diplodia and Dothiorella , viz. Di. acerigena , Di. pistaciicola , Do. camelliae and Do. zanthoxyli . The dominant species isolated across the surveyed regions were Botryosphaeria dothidea , Sardiniella guizhouensis and Diplodia mutila , representing 20%, 14% and 12% of the total isolates, respectively. In addition, most isolates were obtained from Pistacia chinensis (14 isolates), followed by Camellia oleifera (10 isolates). The present study enhances the understanding of Botryosphaeriales species diversity on woody oil plants in Sichuan Province, China.
... Most Diplodia species, including D. malorum, D. mutila, D. corticola, D. africana, and D. rosulata, have aseptate, thick-walled conidia that may stay hyaline for a long time before becoming brown 43,[45][46][47][48] . Nevertheless, in other species, including D. alatafructa, D. pinea, D. scrobiculata, D. seriata, and D. pseudoseriata, the conidia become colored before discharge from the pycnidia and mostly stay non-septate 43,44 . ...
Apple cankers are extremely destructive diseases threatening the global apple industry through
direct and indirect losses. The population structure of the pathogens is of paramount significance
for the development of efficient management strategies. Therefore, phenotypic, pathogenic, and
genetic diversity of Diplodia seriata causing black rot canker of apple was investigated in this study.
All the isolates were included for investigating the in vitro mycelial growth, conidial dimensions, and
pathogenic variability on two-year-old potted apple seedlings. The ISSR approach was used to
investigate the molecular diversity of D. seriata. Mycelial growth rates were found to vary significantly
amongst the isolates; however, there were no major variations seen between the different
geographical groupings of isolates. Pathogenicity tests revealed variations in the size of cankers
among the isolates indicating the presence of virulence variability. The isolates were segregated
into three virulence groups based on canker length. The Bayesian analyses of ISSR data divided the
isolates into two genetic clusters. The genetic clustering of the isolates revealed no relationship
with geographical origin of the isolates. Furthermore, no direct relationship of genetic clustering
was observed with morphological or pathogenic variability. The ISSR primers revealed very high
level of variability in D. seriata; however, no distinct populations of the pathogen existed which is an
indication of high level of gene flow between the diverse geographical populations. According to our
knowledge, this is the first thorough investigation on the diversity of D. seriata associated with apple
black rot canker in India.
... Most Diplodia species, including D. malorum, D. mutila, D. corticola, D. africana, and D. rosulata, have aseptate, thick-walled conidia that may stay hyaline for a long time before becoming brown 43,[45][46][47][48] . Nevertheless, in other species, including D. alatafructa, D. pinea, D. scrobiculata, D. seriata, and D. pseudoseriata, the conidia become colored before discharge from the pycnidia and mostly stay non-septate 43,44 . ...
Apple cankers are extremely destructive diseases threatening the global apple industry through direct and indirect losses. The population structure of the pathogens is of paramount significance for the development of efficient management strategies. Therefore, phenotypic, pathogenic, and genetic diversity of Diplodia seriata causing black rot canker of apple was investigated in this study. All the isolates were included for investigating the in vitro mycelial growth, conidial dimensions, and pathogenic variability on two-year-old potted apple seedlings. The ISSR approach was used to investigate the molecular diversity of D. seriata. Mycelial growth rates were found to vary significantly amongst the isolates; however, there were no major variations seen between the different geographical groupings of isolates. Pathogenicity tests revealed variations in the size of cankers among the isolates indicating the presence of virulence variability. The isolates were segregated into three virulence groups based on canker length. The Bayesian analyses of ISSR data divided the isolates into two genetic clusters. The genetic clustering of the isolates revealed no relationship with geographical origin of the isolates. Furthermore, no direct relationship of genetic clustering was observed with morphological or pathogenic variability. The ISSR primers revealed very high level of variability in D. seriata; however, no distinct populations of the pathogen existed which is an indication of high level of gene flow between the diverse geographical populations. According to our knowledge, this is the first thorough investigation on the diversity of D. seriata associated with apple black rot canker in India.
... Botryosphaeriaceae species have a range of nutritional modes from saprobic to parasitic or endophytic [10,[20][21][22][23][24][25][26][27]. Members of this family are cosmopolitan in distribution and occur on a wide range of monocotyledonous and dicotyledonous hosts: on woody branches, leaves, stems and culms of grasses, and on twigs and in the thalli of lichens [12,21,[28][29][30]. Liu et al. [11] accepted 29 genera in Botryosphaeriaceae based on morphology and molecular data. ...
Botryosphaeriales (Dothideomycetes, Ascomycota) occur in a wide range of habitats as endo-phytes, saprobes, and pathogens. The order Botryosphaeriales has not been subjected to evaluation since 2019 by Phillips and co-authors using phylogenetic and evolutionary analyses. Subsequently, many studies introduced novel taxa into the order and revised several families separately. In addition , no ancestral character studies have been conducted for this order. Therefore, in this study, we re-evaluated the character evolution and taxonomic placements of Botryosphaeriales species based on ancestral character evolution, divergence time estimation, and phylogenetic relationships, including all the novel taxa that have been introduced so far. Maximum likelihood, maximum parsimony, and Bayesian inference analyses were conducted on a combined LSU and ITS sequence alignment. Ancestral state reconstruction was carried out for conidial colour, septation, and nutritional mode. Divergence times estimates revealed that Botryosphaeriales originated around 109 Mya in the early epoch of the Cretaceous period. All six families in Botryosphaeriales evolved in the late epoch of the Cretaceous period (66-100 Mya), during which Angiosperms also appeared, rapidly diversified and became dominant on land. Families of Botryosphaeriales diversified during the Paleogene and Neogene periods in the Cenozoic era. The order comprises the families Aplosporellaceae, Botryosphaeriaceae, Melanopsaceae, Phyllostictaceae, Planistromellaceae and Saccharataceae. Furthermore, current study assessed two hypotheses; the first one being "All Botryosphaeriales species originated as endophytes and then switched into saprobes when their hosts died or into pathogens when their hosts were under stress"; the second hypothesis states that "There is a link between the conidial colour and nutritional mode in botryosphaerialean taxa". Ancestral state reconstruction and nutritional mode analyses revealed a pathogenic/saprobic nutritional mode as the ancestral character. However, we could not provide strong evidence for the first hypothesis mainly due to the significantly low number of studies reporting the endophytic botryosphaerialean taxa. Results also showed that hyaline and aseptate conidia were ancestral characters in Botryosphaeriales and supported the relationship between conidial pigmentation and the pathogenicity of Botryosphaeriales species.
A field investigation of olive trees in Istria, Croatia, revealed branch dieback and cracked bark. Samples of diseased branches were collected from eight different locations and analysed. Additionally, meteorological data from two locations were analysed to determine if there was a connection between climatic changes and the appearance of pathogens in the region. Pathogenicity tests were conducted on olive seedlings. This study provides a description of Biscogniauxia and Sordaria species' morphology and elucidates their phylogeny based on the internal transcribed spacer (ITS), beta-tubulin (TUB2) and translation elongation factor 1-alpha (TEF1-α) regions. This research represents the first documented occurrence of Biscogniauxia mediterranea causing charcoal disease in olive trees in Croatia. Additionally, it is the first report of Biscogniauxia nummularia (Bull.) Kuntze and Sordaria fimicola causing diseases in olive trees anywhere in the world. Furthermore, this study marks one of the initial forays into molecular investigations of these species isolated from olive trees. Considering the potential threat posed by the inherent aggressiveness of Biscogniauxia species, further research is deemed necessary to curb the development of charcoal disease.
This article is the 15th contribution in the Fungal Diversity Notes series, wherein 115 taxa from three phyla, nine classes, 28 orders, 48 families, and 64 genera are treated. Fungal taxa described and illustrated in the present study include a new family, five new genera, 61 new species, five new combinations, one synonym, one new variety and 31 records on new hosts or new geographical distributions. Ageratinicolaceae fam. nov. is introduced and accommodated in Pleosporales. The new genera introduced in this study are Ageratinicola, Kevinia, Pseudomultiseptospora (Parabambusicolaceae), Marasmiellomycena, and Vizzinia (Porotheleaceae). Newly described species are Abrothallus altoandinus, Ageratinicola kunmingensis, Allocryptovalsa aceris, Allophoma yuccae, Apiospora cannae, A. elliptica, A. pallidesporae, Boeremia wisteriae, Calycina papaeana, Clypeococcum lichenostigmoides, Coniochaeta riskali-shoyakubovii, Cryphonectria kunmingensis, Diaporthe angustiapiculata, D. campylandrae, D. longipapillata, Diatrypella guangdongense, Dothiorella franceschinii, Endocalyx phoenicis, Epicoccum terminosporum, Fulvifomes karaiensis, F. pannaensis, Ganoderma ghatensis, Hysterobrevium baoshanense, Inocybe avellaneorosea, I. lucida, Jahnula oblonga, Kevinia lignicola, Kirschsteiniothelia guangdongensis, Laboulbenia caprina, L. clavulata, L. cobiae, L. cosmodisci, L. nilotica, L. omalii, L. robusta, L. similis, L. stigmatophora, Laccaria rubriporus, Lasiodiplodia morindae, Lyophyllum agnijum, Marasmiellomycena pseudoomphaliiformis, Melomastia beihaiensis, Nemania guangdongensis, Nigrograna thailandica, Nigrospora ficuum, Oxydothis chinensis, O. yunnanensis, Petriella thailandica, Phaeoacremonium chinensis, Phialocephala chinensis, Phytophthora debattistii, Polyplosphaeria nigrospora, Pronectria loweniae, Seriascoma acutispora, Setoseptoria bambusae, Stictis anomianthi, Tarzetta tibetensis, Tarzetta urceolata, Tetraploa obpyriformis, Trichoglossum beninense, and Tricoderma pyrrosiae. We provide an emendation for Urnula ailaoshanensis Agaricus duplocingulatoides var. brevisporus introduced as a new variety based on morphology and phylogeny.
Ash trees (Fraxinus spp.) are one of the most important ornamental trees in the green space of cities. To evaluate the fungi associated with decline and dieback of ash trees, the symptomatic samples from branches, trunks, and roots of two species of Fraxinus (European Fraxinus, F. excelsior and Van, F. rotundifolia) were collected from Ardabil and Namin during the summer and autumn of 2018–2019. From the 60 samples, 81 fungal isolates were recovered. Based on morphological features of all isolates together with sequence data of tef-1α gene and specific primers of some Fusarium and Neocosmospora species, 21 fungal species were identified, i.e., Alternaria, Chaetomium, Clonostachys, Cytospora, Fusarium, Microascus, Microsphaeropsis, Neocosmospora, Peyronellaea and Phialophora. Neocosmospora solani, Cytospora chrysosperma and F. oxysporum had the highest abundance, respectively. Pathogenicity test was performed by excised shoot for F. cerealis, F. equiseti, F. oxysporum and N. solani excided shoot method and for C. chrysosperma on excided shoot method and also on two years old ash saplings in greenhouse. Our results showed that all examined species except F. cerealis and F. equiseti cause discoloration of wood texture at the inoculation site. According to our knowledge, most of the fungal species identified in this study, are reported for the first time on ash trees worldwide. Besides, F. denticulatum is a new record to the Iranian mycobiota.
Although Botryosphaeria species are known to cause cankers and dieback in many different woody hosts,
their importance in grapevines has been largely ignored. Indeed, they are more often regarded as saprophytes or
weak pathogens. In the work presented here the species of Botryosphaeria associated with wood and trunk diseases
of grapevines in Portugal were determined. Three species, namely, B. obtusa, B. parva, and B. lutea, were regularly
associated with trunk dieback, wood necrosis, brown wood streaking, cane bleaching or incomplete grafts.
Botryosphaeria parva was the most common and widely distributed species. Botryosphaeria dothidea and B. stevensii
were less common; the former was found on bleached canes and on necrotic tissues at the graft union while the latter
was isolated from necrotic buds, and occasionally from brown streaks in the wood. These data indicate that B. parva
is associated with many of the symptoms normally linked with infection by other fungi in the grapevine decline
syndrome. To stimulate further research on this genus, descriptions of the species associated with grapevines and an
identification key are provided.
In October, 2006, 1,000 olive fruits (Olea europaea) were collected to study latent infections of Colletotrichum spp., causal agent of anthracnose, in an olive orchard in Cordoba Province (southern Spain). The fruits were incubated at 22 to 24°C and 100% relative humidity. Thirteen percent of the fruits showed a black rot that covered part or all of the fruit and pycnidia formed on the fruit surface. The fungus most consistently isolated from affected fruits was identified as Diplodia seriata, the anamorph of “Botryosphaeria” obtusa, by morphological criteria (1). Pathogenicity tests were performed on 50 immature and 50 mature fruits of olive cv. Hojiblanca. The fruits were washed in sterilized water with Tween 20 at 20 μl/liter and surface sterilized in 20% sodium hypochlorite for 2 min. Twenty-five of the immature and 25 mature fruits were wounded with a sterile 0.5-mm-diameter needle, inoculated by immersion in aqueous conidial suspensions (2.2 × 105 conidia ml–1) for 30 min. The same number of immatur...
Bootstrapping is a common method for assessing confidence in phylogenetic analyses. Although bootstrapping was first applied in phylogenetics to assess the repeatability of a given result, bootstrap results are commonly interpreted as a measure of the probability that a phylogenetic estimate represents the true phylogeny. Here we use computer simulations and a laboratory-generated phylogeny to test bootstrapping results of parsimony analyses, both as measures of repeatability (i.e., the probability of repeating a result given a new sample of characters) and accuracy (i.e., the probability that a result represents the true phylogeny). Our results indicate that any given bootstrap proportion provides an unbiased but highly imprecise measure of repeatability, unless the actual probability of replicating the relevant result is nearly one. The imprecision of the estimate is great enough to render the estimate virtually useless as a measure of repeatability. Under conditions thought to be typical of most phylogenetic analyses, however, bootstrap proportions in majority-rule consensus trees provide biased but highly conservative estimates of the probability of correctly inferring the corresponding clades. Specifically, under conditions of equal rates of change, symmetric phylogenies, and internodal change of less-than-or-equal-to 20% of the characters, bootstrap proportions of greater-than-or-equal-to 70% usually correspond to a probability of greater-than-or-equal-to 95% that the corresponding clade is real. However, under conditions of very high rates of internodal change (approaching randomization of the characters among taxa) or highly unequal rates of change among taxa, bootstrap proportions >50% are overestimates of accuracy.
A description is provided for Diplodia pinea . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Pinus species. Also on Abies excelsa, Araucaria cunninghamii, Chamaecyparis lawsoniana, Cupressus macrocarpa, Cupressus lusitanica, Cupressus sempervirens, Picea abies, Pseudotusga menziesii, P. taxifolia and Thuja orientalis [Platycladus orientalis] . DISEASES: Tip and twig blight, stag-head, red top, bud-wilt and seedling collar rot of conifers. Causes stunting of new growth, browning of needles, bending or curling of young shoots and discoloration and death of parts of the crown. Also affecting germination of Pinus seed and causing blight and dieback of coniferous seedlings in the nursery. Frequently found as a wound parasite of injured or weak trees causing bark cankers and dieback of branches and as a saprophyte causing blue-stain of sap-wood of fallen or freshly cut timbers (17: 150; 36: 436; 41: 339). GEOGRAPHICAL DISTRIBUTION: Africa (Kenya, Malawi, Mauritius, Mozambique, Rhodesia, S. Africa, Tanzania, Uganda); Asia (Japan, Malaysia, Thailand); Australasia & Oceania (Australia, New Zealand); Europe (Austria, Belgium, France, Germany, Italy, Portugal, Rumania, Spain, Sweden, U.K.); North America (Canada, U.S.A.); Central America & West Indies (Jamaica), South America (Argentina, Brazil, Chile, Paraguay). (CMI Map 459, 1969). TRANSMISSION: The pathogen is disseminated as spores by wind, rain and in fluid secreted by the pine spittle-bug, Aphrophora parallela and as mycelium on seed of Pinus (16: 219; 21: 398). Infection may take place through natural infection courts such as leaf traces or cones and cone-stalks (5: 708; 48, 3187) as well as through living tissues following wounding (31: 1; 44, 889; 48, 3187) or damage from hail (8: 535; 16: 219; 20: 150), frost (21: 398; 40: 388) or insects (pine spittle-bug, 21: 398; bark beetles, Myelophilus piniperda [Tomicus piniperda] , 14: 727) or attack by rust, Cronartiurn ribicola , causing progressive wilt in Pinus halepensis (25: 493) or by drought (14: 65) or other unfavourable growing conditions (13: 426, 553; 16: 148). Gilmour found that the amount of infection in P. radiata appeared to be correlated with trunk wounding and varied with the type of pruning tool used: secateurs, 12%; axe, 48%, slasher, 68% (44, 889). The pathogen may persist in infected tissues up to 400 days (48, 3187) and is commonly saprophytic on forest debris which provides a source of abundant spores during periods of rain (41: 339).
The main purpose of this research was to examine the endophytic fungal composition of leaves and twigs of Blepharocalyx salicifolius, Myrceugenia glaucescens and Acca sellowiana (Myrtaceae-Myrtoideae) growing within their natural distribution area in southern central Uruguay. Twig and leaf segments were plated on 2% MEA. The percent of colonization ranged from 27% (M. glaucescens xylem) to 78% (Blepharocalyx bark). Xylaria enteroleuca, Pestalotiopsis guepinii, and sterile mycelia colonized several tissues of all host species. Simple correspondence analysis showed differences in endophyte composition between M. glaucescens and the other two hosts, suggesting host preferences. Conversely, A. sellowiana and B. salicifolius were characterized by similar species composition and the slight difference observed was due to some species isolated in only one of them or in both but with different relative frequency of isolation. Ordination resulting from cluster analysis showed that the endophytic composition of twig xylem and bark was similar in B. salicifolius and A. sellowiana. In M. glaucescens tissue preference was not evident. The endophytes Sphaeropsis sapinea, Botryosphaeria dothidea and Colletotrichum gloeosporioides found here were also present in Eucalyptus spp. cultivated as non-native in Uruguay but the endophytic diversity of the three hosts was nearly similar to that of Eucalyptus spp.
— We studied sequence variation in 16S rDNA in 204 individuals from 37 populations of the land snail Candidula unifasciata (Poiret 1801) across the core species range in France, Switzerland, and Germany. Phylogeographic, nested clade, and coalescence analyses were used to elucidate the species evolutionary history. The study revealed the presence of two major evolutionary lineages that evolved in separate refuges in southeast France as result of previous fragmentation during the Pleistocene. Applying a recent extension of the nested clade analysis (Templeton 2001), we inferred that range expansions along river valleys in independent corridors to the north led eventually to a secondary contact zone of the major clades around the Geneva Basin. There is evidence supporting the idea that the formation of the secondary contact zone and the colonization of Germany might be postglacial events. The phylogeographic history inferred for C. unifasciata differs from general biogeographic patterns of postglacial colonization previously identified for other taxa, and it might represent a common model for species with restricted dispersal.
The endophytic mycobiota of healthy twigs and the assemblage of species associated with twig lesions of Eucalyptus globulus and E. grandis planted at the same site in the central west region of Uruguay was examined. Twig segments from E. grandis and E. globulus were plated on 2% malt agar. The diversity of endophytes isolated was low, as was the number of host-specific species. E. globulus endophytes of healthy xylem were different from the colonizers of cracked lesions and healthy bark. Conversely, in E. grandis characterized by black spots, the main difference in species composition was between xylem and bark. Cytospora chrysosperma was isolated from healthy bark and symptomatic twigs of E. globulus, suggesting that symptomatic tissues, such as cracks produced under drought were favourable to saprotrophic expansion.