• Sarvesh Kumar Sood

      Articles written in Proceedings – Plant Sciences

    • Development of male and female gametophytes and integument initiation inPrenanthes brunoniana Wall. (Compositae)

      Sarvesh Kumar Sood Tejinder Singh Thakur

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      The development of gametophytes and initiation of integument are described inPrenanthes brunoniana. Anther wall layers consist of an epidermis, endothecium, a middle layer and tapetum. Endothecium develops fibrous thickenings. Tapetum is of secretary type. Cytokinesis in of simultaneous type. Pollen tetrads are tetrahedral and are shed at the 3-celled stage. Ovule is anatropous, unitegmic and tenuinucellate. Integumentary vascular supply is present. The cells of dermatogen, subdermatogen and inner core all take part in the integument formation. Embryo sac development is of the Polygonum type.

    • Gametophytes, integuments initiation and embryogeny inMicrostylis cylindrostachya (Orchidaceae, Epidendreae)

      Sarvesh Kumar Sood

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      The development of gametophytes, initiation of integuments and embryogeny are described inMicrostylis cylindrostachya. The anther wall consists of an epidermis, fibrous endothecium, one middle layer and secretory tapetum with uninucleate cells. Its development corresponds to the Monocotyledonous type. Cytokinesis is simultaneous. The microspore tetrads are decussate, isobilateral and tetrahedral. At shedding, the pollinia are 2-celled. The ovules are anatropous, bitegmic and tenuinucellate. Both the integuments are dermal in origin. Development of the female gametophyte is of the Monosporic type. Double fertilization occurs. The primary endosperm nucleus degenerates. Development of the embryo corresponds to the Asterad type. The mature embryo is undifferentiated. The seed is non-endospermic and the seed coat is formed entirely by the outer layer of the outer integument.

    • Gametogenesis, integuments initiation and embryogeny in three species of Habenaria (Orchidaceae, Orchideae)

      Sarvesh Kumar Sood

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      InHabenaria edgeworthii, Habenaria elisabethae andHabenaria galeandra the young anther wall consists of epidermis, endothecium, single middle layer and glandular tapetum. Tapetal cells are uninucleate and show dual origin. The microspore tetrads are linear, tetrahedral, decussate and isobilateral. At shedding the microspores are 2-celled. Ovules are anatropous, bitegmic and tenuinucellate. The development of embryo sac is of the Polygonum type. The primary endosperm nucleus degenerates. Development of the embryo in all the 3 species corresponds to the Onagrad type. The seed coat is formed entirely from the outer layer of outer integument.

    • Development of gametophytes, embryogeny and pericarp inGoodyera repens (Orchidaceae, Neottieae)

      Sarvesh Kumar Sood

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      The gametophytes, embryogeny and pericarp of the orchidGoodyera repens are described. The anther wall consists of an epidermis, fibrous endothecium, middle layer and a uniseriate tapetum of binucleate cells. Meiosis is normal. Decussate, isobilateral, linear and tetrahedral pollen tetrads are formed. At shedding the massulae are 2-celled. Ovules are anatropous, bitegmic and tenuinucellate. The inner integrument alone forms the micropyle. Development of the female gametophyte is monosporic. The primary endosperm nucleus degenerates without and division. Development of embryo corresponds to the Asterad type. the mature embryo lacks differentiation. The seeds are minute and nonendospermic. The seed coat is formed entirely by the outer layer of testa.

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