Pollen Abortion in Male‐Sterile Hexaploid Wheat (#x2018;Norin’) Having Aegilops ovata L. Cytoplasm¹

Abstract

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.

Development Anatomy in Wheat of Male Sterility Induced by Heat Stress, Water Deficit or Abscisic Acid

“…Chauhan and Singh (1966) reported three different modes of pollen abortion in the three florets within a single spikelet of cytoplasmic male sterile wheat. Alternatively the anatomical differences may be related to the stage of development at which a floret experienced stress.…”

Comparative microsporangium development in male‐fertile and male‐sterile flowers ofConsolea(Cactaceae): When and how does pollen abortion occur

“…In general, CMS-GCMS lines seem more prone to having several abortion pathways within a line, even in different locules of an anther, and pollen degeneration occurs at various stages (Chauhan & Singh, 1966;Chhabra et al 1997;Smith et al 2002). However, in Consolea, the timing of male sterility is identical for the six species studied and essentially identical in mode of action.…”

“…Recently, emphasis has shifted towards the understanding of stamen and male gametophyte development, and the genes involved in those processes in Arabidopsis thaliana (Chaudhury et al 1994;Sanders et al 1999;Zhang et al 2002). In order to determine the timing and place of the male sterility process, anatomical studies were first performed at the light microscope level (Singh & Rhodes, 1961;Dubey & Singh, 1965;Brooks et al 1966;Joppa et al 1966;Kaul & Singh, 1966;Chauhan & Singh, 1966;Pritchard & Hutton, 1972;Graybosch et al 1984;Yonggen & Rutger, 1984;Sawhney & Bhadula, 1988;Kini et al 1994) and later at the ultrastructural level (Overman & Warmke, 1972;Warmke & Lee, 1977;Horner, 1977;Lee et al , 1980Pollak, 1992;Loukides et al 1995). Recent studies combined inheritance, molecular, and ultrastructure techniques for a more comprehensive analysis of male sterility (Dawson et al 1992;Chaudhury et al 1994;Jin et al 1997;Sanders et al 1999).…”

Meiotic Irregularities in Pollen Sterile Sweet Pepper (<i>Capsicum annuum</i> L.)

“…The effect of mas nuclear factors differs in different species. In most species in which the cytoplasmic male sterility was described, Allium cepa Monosmith-(1927) cited by Jones and Emsweller (1937), Kobabe (1958), Jirik and Novak (1969), Zea mays (Rhoades 1933), Beta vulgaris (Artschwager 1948), Linum usitatissimum (Dubey and Singh 1965), Triticum aestivum (Joppa et al 1965), in hexaploid wheat with the cytoplasm Aegylops ovata (Chauhan and Singh 1966), barley (Kaul and Singh 1966), in pollen sterile hybrids of barley (Schooler 1967), in Sudan grass (Sultanul and Sandal 1967) and others the normal course of meiosis was stated. The abortion of pollen grains occurs only after the release of the tetrads during later stages of microsporogenesis.…”