scholarly journals Development of Male and Female Gametophyte in Symphytum orientale L. (Boraginaceae)

2018 ◽  
Vol 10 (1) ◽  
pp. 124-129
Author(s):  
Filiz VARDAR ◽  
Ertuğrul Ali YAVUZ
Keyword(s):  
Female Gametophyte ◽  
Embryo Sac ◽  
Pollen Grains ◽  
Middle Layer ◽  
Reproductive Behaviour ◽  
Flowering Plant ◽  
Natural Habitats ◽  
Linear Tetrad ◽  
Male And Female ◽  
Developmental Features

The presented study elucidates developmental features of male and female gametophyte in Symphytum orientale L. (Boraginaceae). Flower buds were collected from natural habitats (İstanbul-Turkey) in March-April. The anthers of S. orientale were tetrasporangiate with a persistent epidermis and its wall development conformed to the Dicotyledonous type. The endothecium developed fibrous wall thickenings. The middle layer was short-lived and the cells of the glandular tapetum became double nucleated. In the microspore mother cells cytokinesis originated simultaneously after meiosis and the microspore tetrads were tetrahedral or isobilateral. The mature pollen grains were 3-celled when spread to environment. The ovule was hemianatropous, unitegmic and tenuinucellar. The megaspore mother cell functioned directly from the archesporial cell. Polygonum type embryo sac developed from the chalazal megaspore of a linear tetrad generated after meiosis. The synergids were pyriform and the polar nuclei fused shortly before fertilization. The antipodal cells were large and persistent at the stage of globular embryo. Embryogenesis followed the Chenopodiad type and the endosperm represented cellular type. The detailed embryological data of Symphytum orientale L. (Boraginaceae), which is a herbaceous and perennial flowering plant will improve our knowledge of its reproductive behaviour, and provide to comprehend taxonomic connection with related taxa within the Symphytum/Boraginaceae.

Embryology of Polygonatum (Asparagaceae) and its systematic significance

Phytotaxa ◽  
2018 ◽  
Vol 350 (3) ◽  
pp. 235
Author(s):  
YUAN-YUAN SONG ◽  
YUN-YUN ZHAO ◽  
JIA-XI LIU
Keyword(s):  
Female Gametophyte ◽  
Embryo Sac ◽  
Pollen Grains ◽  
Mature Pollen ◽  
Polygonum Type ◽  
Male And Female ◽  
Systematic Significance ◽  
Embryo Sac Development

In this study, we systematically studied the microsporogenesis, megasporogenesis, as well as development of male and female gametophyte of Polygonatum macropodum and P. sibiricum using the conventional paraffin sectioning technique. Our results showed that 1) microsporocytes cytokinesis is of the successive type; 2) microspore tetrads are tetragonal or tetrahedral; 3) mature pollen grains are two-celled or three-celled; 4) ovary is superior and trilocular, with axile placentas bearing 4–6 anatropous per locule; 5) ovules are anatropous, crassinucellate and bitegmic, with micropyle formed by the inner integument; 6) megaspore tetrads are linear or T-shaped; 7) embryo sac development is typically of Polygonum-type. The embryological features of Polygonatum support its inclusion of Asparagaceae in Asparagales.

Comparative study of gametophyte development in the some species of the genus Onobrychis: Systematic significance of gametophyte futures

Biologia ◽  
2011 ◽  
Vol 66 (2) ◽  
Author(s):  
Abdilkarim Chehregani ◽  
Fariba Mohsenzadeh ◽  
Nayereh Tanaomi
Keyword(s):  
Light Microscopy ◽  
Female Gametophyte ◽  
Male Gametophyte ◽  
Outer Integument ◽  
Embryo Sac ◽  
Pollen Grains ◽  
Polygonum Type ◽  
Male And Female ◽  
Number Of Layers ◽  
Functional Megaspore

AbstractMale 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.

The floral morphology and embryology of Themeda australis (R. Br.) Stapf

1964 ◽  
Vol 12 (2) ◽  
pp. 157 ◽  
Author(s):  
PS Woodland
Keyword(s):  
Embryo Sac ◽  
Pollen Grains ◽  
Low Fertility ◽  
Linear Tetrad ◽  
Polygonum Type ◽  
Morphological Variations ◽  
Endosperm Formation ◽  
Secretory Type ◽  
Successive Cytokinesis ◽  
Mother Cells

A comparative study was carried out between diploid and tetraploid races of Themeda australis from Armidale and Cobar, respectively. Some morphological variations occur in both populations, but sporogenesis and gametogenesis are identical. The anther is tetrasporangiate and the development of its four-layered wall is described. The tapetum is of the secretory type and its cells become binucleate at the initiation of meiosis in the adjacent microspore mother cells which undergo successive cytokinesis. Microspore tetrads are usually isobilateral and the pollen grains are three-celled at dehiscence, which takes place by lateral longitudinal slits. The ovule is of a modified anatropous form and bitegmic, the broad micropyle being formed of both integuments. The single hypodermal archesporial cell develops directly into the megaspore mother cell and the nucellar epidermis undergoes periclinal and anticlinal divisions to form a conspicuous epistase. The chalaza1 megaspore of the linear tetrad gives rise to a Polygonum-type embryo sac. Material from the Armidale population showed one embryo sac per ovule, but two to five embryo sacs were present in that from Cobar. Embryogeny is typically graminaceous and endosperm formation is at first free-nuclear, later becoming cellular. Polyembryony follows fertilization of several embryo sacs within the same ovule. The reasons for low fertility of T. australis and poor germination of seeds are discussed.

scholarly journals Some features of biology of the species genus Crocus (family Iridaceae)

2020 ◽  
pp. 94-100
Author(s):  
S. V. Shevchenko ◽  
N. N. Miroshnichenko
Keyword(s):  
Embryo Sac ◽  
Pollen Grains ◽  
Mature Pollen ◽  
Polygonum Type ◽  
Male And Female ◽  
Research Results ◽  
Nest Box

The article presents the research results of the genesis of biology of Crocus angustifolius and Crocus speciosus . Some aspects of formation of the male and female gametophytes, pollination and seeds formation have been presented. The wall of microsporangium develops centripetally as monocotyledonous and formed consists of the epidermis, endothecium, 2-3 middle layers and secretory tapetum. A tetrad of microspores is formed simultaneously. Mature pollen grains are 2-cell. The ovary is three-celled, the ovary is anatropic, crassinucellous, bitegmal, funiculous. Polygonum-type embryo sac. Pedestal, podium and hypostasis are formed. Both species are entomophilous plants. The fruit is a multi-seeded three-nest box. Both species propagated by seeds and vegetatively using corms.

scholarly journals Embryological studies on Anthemis tinctoria L.

2015 ◽  
Vol 46 (4) ◽  
pp. 547-557 ◽  
Author(s):  
K. Bijok ◽  
T. Pawlak ◽  
B. Kreńska
Keyword(s):  
Chromosome Number ◽  
Embryo Development ◽  
Embryo Sac ◽  
Pollen Grains ◽  
Natural Habitats ◽  
Antipodal Cells

The chromosome number of <i>Anthemis tinctoria</i> from natural habitats in Poland is n=9. The development of pollen grains is normal. The embryo-sac is of tetrasporic type and the number of antipodal cells is seven, all derived from one-cellular archespore. The embryo development is of Aster type and the endosperm is of nuclear type.

scholarly journals On the Embryology of Two Species of Genus Lepidium (Brassicaceae)

HortScience ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 582-588
Author(s):  
Elina Yankova-Tsvetkova ◽  
Ivanka B. Semerdjieva ◽  
Rozalia Nikolova ◽  
Valtcho D. Zheljazkov
Keyword(s):  
Embryo Sac ◽  
Pollen Grains ◽  
Middle Layer ◽  
Reproductive Capacity ◽  
Marginal Lands ◽  
Potential Development ◽  
The Family ◽  
Mature Ovule ◽  
The Stability ◽  
Cultivation Techniques

Some species of genus Lepidium of the family Brassicaceae are ruderal plants, and they can grow well on less fertile soils and may have potential as oilseed crops for marginal lands. To develop cultivation techniques for wild species, the reproductive capacity of the species needs to be revealed. The objective of this work was embryological study of two Lepidium species (L. campestre and L. ruderale). As a result of the study, the main features of male and female generative spheres were established. Male generative sphere: The anther is tetrasporangiate and its wall, the development of which follows the monocotyledonous-type, consists of epidermis, endothecium, one middle layer, and glandular tapetum. Predominantly, tetrahedral microspore tetrads form after simultaneous type of microsporogenesis. The mature pollen grains are two-celled. Female generative sphere: The mature ovule is ana-amphytropous, crassinucellate, and bitegmic with unicellular archesporium that functions as a megaspore mother cell without cutting off of parietal cells. The development of the embryo sac follows the polygonum-type development. The embryo and endosperm develop after the onagrad-type embryogenesis. The established peculiarities of the reproductive biology characterize the studied species as sexually reproducing taxa that guarantee the stability of size of their populations. This is important for the conservation of these species as part of the Bulgarian flora biodiversity given their status of valuable medicinal plants. The data obtained will contribute to the knowledge of the embryological characteristic of genus Lepidium. The results contribute to the understanding of Lepidium biology and potential development of Lepidium species as oilseed cash crops for marginal lands.

Sporogenesis, Gametogenesis, and embryogeny of Wahlenbergia bicolor N. Lothian

1963 ◽  
Vol 11 (2) ◽  
pp. 152 ◽  
Author(s):  
G Want
Keyword(s):  
Mother Cell ◽  
Embryo Sac ◽  
Pollen Grains ◽  
Type A ◽  
Middle Layer ◽  
Anther Wall ◽  
Suspected Case ◽  
Polygonum Type ◽  
Chalazal Megaspore ◽  
Coastal Species

In Wahlenbergia bicolor, the anther wall is composed of four layers: epidermis, endothecium, middle layer, and tapetum. Wall formation and microsporogenesis are described, and the pollen grains are shed at the two-celled condition. The ovules are tenuinucellate, with a hypodermal archesporial cell which develops directly as the megaspore mother cell. Megasporogenesis is normal, and a monosporic eight-nucleate embryo sac of the most common Polygonum type develops from the chalazal megaspore. The antipodals degenerate before fertilization. The development of the embryo is of the solanad type. A suspected case of polyembryony was observed. The endosperm is cellular from its inception, and so conforms to the Codonopsis type. A micropylar and a chalazal haustoriurn, both consisting of two uninucleate cells, are formed from the endosperm. Comparative studies were made with a known but as yet undescribed coastal species of Wahlenbergia, and no differences were found.

Cytological and histological studies on male and female gametophyte of endangered species Amygdalus nana in Slovakia

Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Renáta Chudíková ◽  
Ľuba Ďurišová ◽  
Tibor Baranec ◽  
Ivan Ikrényi
Keyword(s):  
Fruit Set ◽  
Abiotic Factors ◽  
Reproductive Potential ◽  
Pollen Grains ◽  
Reproductive Organs ◽  
Great Variability ◽  
Ornamental Plant ◽  
Natural Habitats ◽  
Male And Female ◽  
Female Reproductive Organs

AbstractAmygdalus nana L. (Dwarf Russian Almond) a well-known ornamental plant is endangered in its natural habitats on the territory of Slovakia. Using methods of cytology and embryology, the stages of reproductive cycle of the species were clarified. Especially the development of the male and female reproductive organs, processes of the fertilization and formation of the embryo were studied. The reduction of reproductive potential was caused by synergic influence of negative biotic and abiotic factors. Despite the presence of degenerated, misshapen pollen grains and a great variability in shape and size, a sufficient amount of normally developed viable pollen grains originated within the species Amygdalus nana. We did not observe serious disturbances during megasporogenesis and megagametogenesis, the reduction in fruit set was caused by the degeneration of ovules after unsuccessful pollination (unfavourable conditions during the flowering period) and after unsuccessful seed development, caused mainly by damages of reproductive organs by pests.

scholarly journals REPRODUCTIVE BIOLOGY OF TWO EDIBLE HONEYSUCKLES [Lonicera edulis Turcz. ex Freyn., Lonicera kamtchatica (Sevast.) Pojark.] IN THE CONDITIONS OF SOUTHWESTERN SLOVAKIA

2020 ◽  
Vol 19 (3) ◽  
pp. 63-72
Author(s):  
Ľuba Ďurišová ◽  
Tünde Juríková ◽  
Pavol Jr Eliáš ◽  
Jiří Mlček
Keyword(s):  
Female Gametophyte ◽  
Pollen Grains ◽  
Reproductive Organs ◽  
Climatic Conditions ◽  
Pollen Grain ◽  
Flower Initiation ◽  
Winter Dormancy ◽  
Normal Appearance ◽  
Male And Female ◽  
Female Gametophyte Development

The formation and development of reproductive organs and fruits was examined for two edible honeysuckle species Lonicera edulis Turcz. ex. Freyn. and Lonicera kamtchatica (Sevast.) Pojark. ‘Gerda’ using cytological and embryological methods. We found out that the flower initiation has began during June in the conditions of southwestern Slovakia. Male and female archespores were differentiated before entering winter dormancy. In most cases we have observed normally developed tetrads, normal appearance of microspores, two-celled polen grains and mature pollen grain. In both species a sufficient amount of normally developed pollen grains was observed. Disturbances during female gametophyte development occurred occasionally, most mature ovules contained 7 cells female gametophyte. Our research pointed to fact that the species are protogynous. Flowering usually takes place in the first half of April. The fruits were mature in the second half of May. We have found that 10 to 11 fully developed seeds have evolved in the fruits of both representatives of Lonicera on average. The above results show the suitability of L. edulis and L. kamtchatica cultivation in SW Slovakia with a relatively low risk of fruit loss due to climatic conditions.

scholarly journals Female gametophyte and pollen tube of Epilobium palustre L.

2015 ◽  
Vol 46 (4) ◽  
pp. 603-615 ◽  
Author(s):  
Józef Bednara
Keyword(s):  
Pollen Tube ◽  
Internal Structure ◽  
Female Gametophyte ◽  
Distal Part ◽  
Embryo Sac ◽  
Apical Part ◽  
Filiform Apparatus ◽  
Linear Tetrad ◽  
Fibrillar Material ◽  
Rough Er

The monosporic, tetranucleate embryo sac of <i>Epilobium palustre (Onagraceae)</i> develops from the micropylar megaspore in a linear tetrad. In mononucleate embryo sacs a peculiar chromatic structure associated with a nucleolus appears in the nucleus. This structure seems to be formed by fibrillar material and is not visible in the subsequant stages of development. A large amount of rough ER cisternae occurs in the late mononucleate stage, during the binucleate stage their contents become optically dense. It the early tetranucleate stage the amount of ER is small, it increases again in the developing synergids and central cell. Numerous amyloplasts present in the mononucleate embryo sac loose their starch grains and some are transformed into cup-shaped plastids or proplastids. They are passed on to each of the embryo sac cells. The growth of the pollen tube ceases immediately after the penetration through the filiform apparatus of a synergid. At the apex of the tube a pore is formed. At the last stages of the penetration the apical part of the pollen tube becomes separated by a transverse partition from the distal part of the tube. The contents of the both parts differ in their internal structure. The distal part contains cytoplasm with numerous organoids, while the apical part is mainly filled with spherical bodies.

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