Pollen Abortion in Male-Sterile Hexaploid Wheat (#x2018;Norin’) Having Aegilops ovata L. Cytoplasm1
- S. V. S. Chauhan and
- S. P. Singh2
Another development and microsporogenesis were compared in male-fertile wheat and a male-sterile line, Nr 26. Premeiotic stages of anther development in both the strains are more or less normal, but in later stages, the sterile line shows abnormal development of three types. All three are present in every spikelet, but only one is observed in a single floret. In the central flower of the spikelet, the tapetal layer degenerates before the separation of sporogenous cells, followed by the degeneration of the latter. The degenerated mass is soon absorbed and the mature anther is left with only an epidermal layer. In one of the lateral flowers, the tapetum remains intact and is accompanied by the increase in nuclear size. Later, with the differentiation of exine and intine in microspores, the tapetal layer is completely absorbed. The pollen grains are devoid of germ pore, cytoplasm, and nuclei. The third type results in the formation of a tapetal periplasmodium when microspore mother cells enter meiosis. The contents of the plasmodium and microspore mother cell intermingle and start degenerating. The anthers are left with an epidermis, an endothecium and a degenerated mass of plasmodium and microspore mother cells. Male-sterility in all the three types seems to result from improper nourishment of the developing sporogenous cells or the microspores due to abnormal behaviour of the tapetum.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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