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Vigna adenantha. (a-d) Longitudinal section of developing ovules showing initiation of integuments and anatropous curvature, (e) Mature anacampylotropous ovule. Bar 1 = 50 µm, for (a); Bar 2 = 50 µm, for (b-d); Bar 3 = 25 µm, for (e).
Source publication
Ovule development, megasporogenesis and megagametogenesis were studied in Macroptilium bracteatum, Phaseolus augusti, P. vulgaris var. aborigineus and Vigna adenantha to elucidate their taxonomic position. The ovule is anacampylotropous, bitegmic and crassinucellate. Megaspore tetrads are linear in M. bracteatum and T-shaped in the other three spec...
Contexts in source publication
Context 1
... the four analyzed species the mature ovules are anacampylotropous, bitegmic and crassinucellate (Figs. 1e,f, 2b,f, 3e, 4i, 6e). The ovule originates as a small protuberance from the marginal placenta (Fig. 3a). The ovule primordium is bizonate in longitudi- nal section. It is straight at the beginning but starts (Figs. 2a,d,c, 3b,c, ...
Context 2
... outer integument develops more rapidly than the inner integument (Fig. 2e), so at the dyad stage it encloses the inner integument and reaches the nucellar end (Fig. ...
Context 3
... 2c, 3e; 6e). The inner integument opposite the raphe never reaches the micropylar end of the nucellus. In conse- quence, the micropyle is composed of an exostome formed by the outer integument and by an endosto- matic channel delimited by the inner integument at the raphe side and by the internal face of the outer integument at the opposite side (Figs. 3e, 4g, ...
Context 4
... of the cells of the hypodermal layers develops directly into the archesporial cell (Figs. 3a, 4a), which divides into a primary parietal cell and an MMC (Fig. 3b). In M. bracteatum only, the primary parietal cell undergoes further periclinal divisions to form the parietal tissue. This situates the MMC deep within the nucellus (crassinucellate) (Fig. ...
Context 5
... of the cells of the hypodermal layers develops directly into the archesporial cell (Figs. 3a, 4a), which divides into a primary parietal cell and an MMC (Fig. 3b). In M. bracteatum only, the primary parietal cell undergoes further periclinal divisions to form the parietal tissue. This situates the MMC deep within the nucellus (crassinucellate) (Fig. ...
Citations
... Sepals and petals cover all parts of the reproductive organs in early stages for more protection in these sensitive periods. Extensive studies have been done on Papilionoideae embryology (Rembert 1971;Prakash 1987;Ashrafunnisa & Pullaiah 1999;Faigón-Soverna et al. 2003;Galati et al. 2006). But in Alhagi species, the pistil and ovule have rigid covers with a high accumulation of different compounds (e.g., phenolic compounds). ...
Reproductive organs, in flowering plants, are sensitive to stressful environments. Alhagi persarum Boiss. & Buhse copes with the stresses and produce reproductive organs under difficult climatic conditions. Embryological characters of this plant were investigated for the first time using different microscopy and staining techniques. The results of this study showed unique reproductive characters and strategies in A. persarum that we named reproductive adaptation. These characters have roles in protection and nutrition of reproductive organs, some of which were visible in ovule: accumulation of phenolic compounds, presence of ovular endothelium with its cuticle coat, hypostase, postament, endosperm haustorium, presence of operculum, curvature of the embryonic axis. The other characters in the seed are macrosclereid cells with cuticle coat, double palisade layer and lignified tracheids in hilar groove. Thickness increasing of endothecium and exine are the adaptive characters in anther. Unlike many of the stress-sensitive plants, all developmental stages of the embryo sac, anther, pollen and pollen tube are without any defects in these stress-tolerant plants. Seed germination rate is low in this species that is due to the hardness of seed coat which causes seed deep exogenous dormancy. This dormancy is also a developmental program for stress tolerance to keep seed viability for a long time in difficult conditions.
... While general descriptions of reproductive development in members of the Fabaceae have been published from a physiological and developmental perspective (Brown 1917;Mitchel 1975;Rembert 1977;Albertsen and Palmer 1979;Kennell and Horner 1985;Moço and Mariath 2003;Soverna et al. 2003;Rodriguez-Riaños et al. 2006;Chehregani and Tanaomi 2010;Ghassempour et al. 2011), there is surprisingly scarce information on micro-and megagametogenesis in Vigna. An important prerequisite for developing robust hybrid seed production systems or attempting to alter reproduction in cowpea is a clear understanding of the temporal and spatial events of sexual male and female gametophyte formation in relation to flower morphology and supporting cytological tools to efficiently and accurately examine changes induced by hybridization, mutation, or transgenic approaches. ...
Key message:
Cowpea reproductive tools. Vigna unguiculata L. Walp. (cowpea) is recognized as a major legume food crop in Africa, but seed yields remain low in most varieties adapted to local conditions. The development of hybrid cowpea seed that could be saved after each generation, enabling significant yield increases, will require manipulation of reproductive development from a sexual to an asexual mode. To develop new technologies that could support the biotechnological manipulation of reproductive development in cowpea, we examined gametogenesis and seed formation in two transformable, African-adapted, day-length-insensitive varieties. Here, we show that these two varieties exhibit distinct morphological and phenological traits but share a common developmental sequence in terms of ovule formation and gametogenesis. We present a reproductive calendar that allows prediction of male and female gametogenesis on the basis of sporophytic parameters related to floral bud size and reproductive organ development, determining that gametogenesis occurs more rapidly in the anther than in the ovule. We also show that the mode of megagametogenesis is of the Polygonum-type and not Oenothera-type, as previously reported. Finally, we developed a whole-mount immunolocalization protocol and applied it to detect meiotic proteins in the cowpea megaspore mother cell, opening opportunities for comparing the dynamics of protein localization during male and female meiosis, as well as other reproductive events in this emerging legume model system.
... Embryological studies in Papilionoideae (Ashrafunnisa and Pullalah 1999;Riahi et al. 2003;Faigo´n-Soverna et al. 2003;Moço and Mariath 2003;Zulkarnain 2005;Galati et al. 2006;Rezanejad 2007;Rodriguez-Pontes 2008;Riahi and Zarre 2009;Salinas-Gamboa et al. 2016) and a few embryological studies in Onobrychis (Chehregani et al. 2011;Ghassempour and Majd 2012) have provided useful characters in embryogenesis and classification. Therefore, in this study we investigate detailed embryological processes in O. persica using bright field, polarizing and fluorescence microscopy and compare them with some spices in this genus. ...
... The ovules are crassinucellate in Fabaceae (Faigo ´n- Soverna et al. 2003;Riahi et al. 2003;Moço and Mariath 2003;Galati et al. 2006;Rezanejad 2006), which were also found in O. persica. Asymmetrical growth at the funicular region is the reason for this anatropous curvature in O. persica, like other legumes (Bouman and Boesewinkel 1991;Galati et al. 2006;Rezanejad 2006;Riahi and Zarre 2009) and our study indicates that the young ovule is hemianatropous and then it change to anatropous one. ...
... The tetrads of megaspores in O. persica, most legumes and our previous study on Onobrychis except for O. schahuensis are T-shaped (Table 1) (Chehregani and Majd 1992;Faigo´n-Soverna et al. 2003;Riahi et al. 2003;Chehregani et al. 2011). But the tetrad shape in Fabaceae can be different (Moço and Mariath 2003;Galati et al. 2006;Rodriguez-Pontes 2008). ...
Developmental aspects of anther, pollen grains, ovule, embryo and seed has described in Onobrychis persica Sirj. and Rech.f. (Fabaceae) under bright field, polarizing and fluorescence microscopy. Anther development starts when the flowers are very small. The anther is tetrasporangiate, and its wall development follows the dicotyledonous type and consists of four layers: epidermis, endothecium, middle layer and a secretory tapetum. Cytokinesis is simultaneous and arrangement of microspores is tetrahedral and tetragonal. Fibrous thickenings are developed in the endothecium when shed. Ellipsoidal tricolpate pollen grains are two-celled when anthers dehisce. The young hemianatropous ovule changes to a anatropous, crassinucellar and bitegumic mature one with zigzag micropyle. Meiosis of megasporocytes results in a T-shaped tetrad. The chalazal megaspore develops into an eight-nucleate embryo sac with the pattern of Polygonum type. The polar nuclei remain separated before fertilization. After cellularization of endosperm, peripheral cells show dense lipid content. The axial embryo shows fleshy cotyledons, which accumulate lipid and starch. The inner integument differentiates into an endothelium and largely vanishes during development while the outer one produces several layers and establishes the typical seed coat structure: macrosclereid cells, osteosclereids and parenchyma cells. Different compounds, such as starch and lipid content were demonstrated with special staining in the tissues. The systematic significance of the embryological characters is discussed in O. persica.
... Embryological characters are useful and important in taxonomical and evolutionary analyses (e.g., Herr, 1984;Prakash, 1987;Tobe, 1989;Igersheim and Endress, 1998;Endress and Igersheim, 2000;Igersheim et al., 2001;Endress 2005;Siuta et al., 2005;Płachno and Świątek, 2010;Płachno, 2011;Kuta et al., 2012). Studies on ovule morphology and histology can also help in understanding evolutionary changes (Soverna et al., 2003;Endress, 2005Endress, , 2011Wang and Ren, 2007;Mariath, 2008, 2010;Płachno and Świątek, 2009;Fagundes and Mariath, 2014). According to Anderberg et al. (2007), Taraxacum and Chondrilla are classified within subfamily Cichorioideae. ...
Many Asteraceae species have been introduced into horticulture as ornamental or interesting exotic plants. Some of them, including Solidago and Galinsoga, are now aggressive weeds; others such as Ratibida are not. Special modifications of the ovule tissue and the occurrence of nutritive tissue have been described in several Asteraceae species, including invasive Taraxacum species. This study examined whether such modifications might also occur in other genera. We found that the three genera examined – Galinsoga (G. quadriradiata), Solidago (S. canadensis, S. rigida, S. gigantea) and Ratibida (R. pinnata) – differed in their nutritive tissue structure. According to changes in the integument, we identified three types of ovules in Asteraceae: “Taraxacum” type (recorded in Taraxacum, Bellis, Solidago, Chondrilla), with well-developed nutritive tissue having very swollen cell walls of spongy structure; “Galinsoga” type (in Galinsoga), in which the nutritive tissue cells have more cytoplasm and thicker cell walls than the other integument parenchyma cells, and in which the most prominent character of the nutritive tissue cells is well-developed rough ER; and “Ratibida” type (in Ratibida), in which the nutritive tissue is only slightly developed and consists of large highly vacuolated cells. Our study and future investigations of ovule structure may be useful in phylogenetic analyses
... Urb. complex (Faigón Soverna 2002;Faigón Soverna et al. 2003). ...
Background:
The inflorescences of the genus Vigna Savi have extrafloral nectaries (EFNs) among the flowers whose origin is still unknown. The disposition, anatomy and morphology, as well as the ontogeny of the extrafloral nectaries (EFNs) associated with the inflorescences of Vigna adenantha (G.F.W. Meyer) Maréchal, Mascherpa & Stainier (Leguminosae, Papilionoideae, Phaseolae) were studied. Besides, the ultrastructure of the secretory stage was described.
Results:
The inflorescence, a raceme, bears a brief globose secondary axis in each node with 2 flowers and 5-7 EFNs, which develop in acropetal direction. Each EFN originates from the abscission of a flower bud that interrupts its development, resulting in an elevated EFN. This secretory structure is formed by a ring of epidermal and parenchymatic cells surrounding a group of elongated central cells. The nectary is irrigated by phloem and xylem. Four developmental stages proceed; each one relates to a different embryological stage of the flowers in each secondary axis.
Conclusions:
The first functional EFN of each secondary axis of the inflorescence reaches its maturity when both the pollen grains and the embryo sacs are completely developed and the flowers begin to open. The secretion is granulocrine. The following EFNs develop in the same way.
... Most mellitophilous papilionoids, for example, exhibited stigma with thin and continuous cuticle (see Table 1), which can be ruptured by bees in their visits to flowers exposing the stigmatic surface or the exudate, depending on the species (see Table 2). These features were reported in Trifolium pratense (Heslop-Harrison & Heslop-Harrison, 1983), Vicia faba (Lord & Heslop-Harrison, 1984), Glycine max (Tilton et al., 1984), Cytisus striatus, Retama sphaerocarpa (Rodríguez-Riaño et al., 1999), Macroptilium bracteatum, Phaseolus augusti, P. vulgaris, Vigna adenantha (Soverna et al., 2003), Cytisus multiflorus (Rodríguez-Riaño et al., 2004), Vigna caracalla Caesalpinia echinata, (g) Parkia pendula, (h) Inga congesta, (i) Taralea oppositifolia. The stigmatic surface is composed of papilla (a, c) or simple trichomes (b, f); some cells contain phenolics (a, b, f). ...
The great stigma diversity in angiosperms implies a choice of criteria for stigma classification, which nowadays is characterized as dry (= little or no secretory surface and exudate retained by the cuticle and/or protein pellicle), wet (= conspicuous secretory surface, abundant in fluid exudate) and semidry (exudate retained by cuticle and/or protein pellicle). Despite being a very species-rich family, whose representatives exhibit a wide floral variation, no comparative studies of stigma diversity have been done for the whole Leguminosae. In order to assess the stigma morphological diversity in legumes and to evaluate the criteria used in the main classifications of the stigma, we compared the stigma morphology in 15 distinct legume lineages. In addition, we evaluated the stigma classification in other 152 legume species whose morphology was already described in the literature. Stigmas were removed from floral buds and flowers and processed for analyses under scanning electron and light microscopes. The stigma of the study legumes exhibits quite variable morphology, mainly concerning the diameter, the occurrence of an orifice or a furrow, the coating, the cellular composition, and the occurrence, chemical nature and release mechanism of the exudate. This diversity appears to be related mainly to the evolutionary history of the group and also to the selective pressures exerted by different types of pollen and pollinator. More conflicting criteria for stigma classification lie in defining the semidry type, found mostly in papilionoids. For better stigma classification we suggest that stigma morphology be evaluated at the time prior to anthesis, when the cuticle is not yet broken and the exudate is not exposed or drained. In addition, several techniques should be employed for a better classification.
... Female gametophyte development of some genera of Fabaceae has been studied (Folsom & Cass, 1992;Faigon Soverna et al., 2003;Moço & Mariath, 2004;Zulkarnain, 2005;Rodriguez-Riano et al., 2006;Chehregani & Tanaomi, 2010;Chehregani et al., 2011). Recently, ontogenic studies on female gametophyte development have been carried out in Fabaceae, such as Caesalpinia (De Pádua Teixeira et al., 2004), Pterodon emarginatus Vogel. ...
... It has been observed that the polar nuclei in the mature female gametophyte were situated close to the egg apparatus, and the cytoplasm of the central cell was rich in terms of organelles (Algan & Bakar, 1997a). In a group of ovules (22%) containing mature female gametophytes, the polar nuclei fuse to form secondary nuclei (Bakar Büyükkartal, 2008) as is the case in the majority of angiosperm taxa (Faigon Soverna et al., 2003;Rodriguez-Riano et al., 2006;Gotelli et al., 2006;Vardar et al., 2012). Two polar nuclei fuse before fertilisation, and in this experiment the secondary nucleus was found to be of different sizes in a number of samples. ...
The mature female gametophyte in Trifolium pratense L., a natural tetraploid plant, consists of 7 cells: the egg cell, 2 synergids, the central cell, and 3 antipodal cells. This type of mature female gametophyte is known as polygonum. The central cell occupies the largest portion of the mature female gametophyte and the polar nuclei are situated close to the egg apparatus. The cytoplasm of the central cell is rich in organelles. A large number of rough and smooth endoplasmic reticulum, mitochondria, plastids, dictyosomes, ribosomes, starch, and lipid bodies were observed. Differences were identified in this plant between the sizes of polar nuclei and secondary nuclei generated by the fusion of the former. It was observed that the polar nuclei had fused long before the pollen tube entered the female gametophyte, and that the secondary nuclei in some female gametophytes were degenerated before fertilisation.
... The outer integument on the opposite side of the funicular region, in O. andalanica and O. melanotricha grows asymmetrically slower but in O. schahuensis and O. altissima, it grows asymmetrically faster. The nucellus of ovules in Fabaceae is crassinucellate (Prakash 1987; Faigón Soverna et al. 2003; Moco & Mariath 2003; Galati et al. 2006), which were also found in our species. This type has been considered to be the plesiomorphic condition in angiosperms (Sporne 1969). ...
Male and female gametophytes have special characters that show a great variety in different taxa. In this study, gametophytes
of four species belonging to three sections of the genus Onobrychis Mill. were studied with light microscopy. Results showed that the ovular primordium is tetra-zonate and gives rise to an
anatropous ovule. The archesporium may consist of one or more archeosporial cells, but only one of them undergoes meiosis,
forming a linear or T-shaped tetrad. Normally, only a single megaspore is functional which is located in the chalazal position
while the others degenerate very soon. The young ovule is hemi-anatropous but the mature is anatropous, crassinucellar and
bitegmic; integuments form a zig-zag micropyle. A 7-celled embryo-sac is formed corresponding to the Polygonum type. Based on our results, the ovular variable characters are the form and condition of ovary, presence or absence of ovary
peduncle, the number and condition of ovule in ovary, length and width of ovule, length and width of embryo sac, number of
layers in outer integument, condition of megaspore, alignment pattern of the integuments, asymmetrical initiation of the outer
integument, shape of tetrad with the presence of one functional megaspore and so on. The separator characters in male gametophyte
are including tri-cellular pollen grains and the number of tapetum nuclei. According to our study the female gametophyte characters
are more variable than male gametophyte. The present study provides the first report on embryological description in the genus
Onobrychis and also in section Heliobrychis.
Key words
Onobrychis schahuensis
–
O. andalanica
–
O. melanotricha
–
O. altissima
–Fabaceae–microgametophyte–megagametophyte–ovule–pollen
... Comparten el tipo de óvulo campilótropo con micrópila en zig-zag y el saco embrionario tipo Polygonum, como fuera descripto por Speroni & Izaguirre (2001) y es común en la familia (Prakash, 1987). Se confirma la presencia de células antipodales efímeras observadas por Speroni & Izaguirre (2001) para esta especie y por otros autores para otras especies del mismo género o familia (Hindmarsh, 1964;Krupko, 1973;Prakash, 1987;Faigón et al., 2003). También las vías que se establecen para nutrir al saco embrionario y luego al embrión son similares. ...
On the causes of the differential seed production in the anficarpic species Trifolium polymorphum (Leguminosae). Trifolium polymorphum is recognized as one of the best adapted legume in field conditions. It combines different reproductive strategies such as stoloniferous vegetative reproduction and seed reproduction by two types of fruits produced in underground and aerial flowers. These last ones are chasmogamous and underground flowers are cleistogamous. A higher seed production has empirically been detected in underground flowers rather than in aerial ones. In the present work, embryological studies in aerial and underground flowers were carried out in order to determine the existence of ontogenetic causes which may promote productivity differences in both types of seeds. No embryological pre-zygotic cause explaining aerial flowers low productivity was detected. Aerial and underground seeds share ontogenetic characteristics as both types of flowers showed normal ovule and embryo sac development. Similar nutritional pathways for embryo sacs, embryos and endosperms were also observed. In general, flowering represents a high energetic inversion for plant species. Aerial flowering in I polymorphum, though subjected to a strong herbivorous pressure, incorporates genetic variability to populations through cross-pollination and succeeds in facilitating long distance dispersion.
... Comparten el tipo de óvulo campilótropo con micrópila en zig-zag y el saco embrionario tipo Polygonum, como fuera descripto por Speroni & Izaguirre (2001) y es común en la familia (Prakash, 1987). Se confirma la presencia de células antipodales efímeras observadas por Speroni & Izaguirre (2001) para esta especie y por otros autores para otras especies del mismo género o familia (Hindmarsh, 1964;Krupko, 1973;Prakash, 1987;Faigón et al., 2003). También las vías que se establecen para nutrir al saco embrionario y luego al embrión son similares. ...
Trifolium polymorphum es una leguminosa de pradera con buena adaptación y persistencia en este tipo de vegetación. Combina diferentes estrategias reproductivas como la reproducción vegetativa por estolones y la reproducción por semillas producidas en dos tipos de frutos y flores, subterráneas y aéreas. Las subterráneas son cleistógamas y las aéreas son casmógamas. Empíricamente se ha detectado mayor formación de semillas en los frutos subterráneos que en los aéreos. En el presente trabajo se realizan estudios embriológicos y de desarrollo de semillas en ambos tipos de flores para dilucidar si existen causas ontogenéticas que determinan la productividad diferencial de semillas en ambos tipos de frutos. No se detectaron causas embriológicas pre-cigóticas que expliquen el menor número de semillas en los frutos de las flores aéreas. Ambos tipos de semillas comparten características ontogenéticas y presentan apropiado desarrollo de los óvulos, sacos embrionarios y establecimiento de vías nutricionales para saco embrionario, embrión y endosperma. En general las floraciones insumen un costo energético importante para las especies vegetales. La floración aérea de T. polymorphum, aunque sometida a una fuerte presión de herbivoría del ganado, incorpora variabilidad genética a sus poblaciones a través de la polinización cruzada y permite la dispersión a distancia.Trifolium polymorphum is recognized as one of the best adapted legume in field conditions. It combines different reproductive strategies such as stoloniferous vegetative reproduction and seed reproduction by two types of fruits produced in underground and aerial flowers. These last ones are chasmogamous and underground flowers are cleistogamous. A higher seed production has empirically been detected in underground flowers rather than in aerial ones. In the present work, embryological studies in aerial and underground flowers were carried out in order to determine the existence of ontogenetic causes which may promote productivity differences in both types of seeds. No embryological pre-zygotic cause explaining aerial flowers low productivity was detected. Aerial and underground seeds share ontogenetic characteristics as both types of flowers showed normal ovule and embryo sac development. Similar nutritional pathways for embryo sacs, embryos and endosperms were also observed. In general, flowering represents a high energetic inversion for plant species. Aerial flowering in T. polymorphum, though subjected to a strong herbivorous pressure, incorporates genetic variability to populations through cross-pollination and succeeds in facilitating long distance dispersion.
