Pollen Abortion in Cytoplasmic Male Sterile Sorghum¹

Cytological Studies in Some Male Sterile Jowars (<i>Sorghum vulgare</i>, Pers) and Their Maintainers and Restorers

“…M 22-5-16. The meiosis in the main tainer parent B 385 has been already reported by Singh and Hadley (1961) and their observations are confirmed in the present studies. In all these parents the pachytene chromosomes showed differential stainability.…”

“…Meiosis in the male sterile parents. The details of meiosis upto tetrad forma tion in the male sterile parent A 385 has been reported by Singh and Hadley (1961) and Shambulingappa and Magoon (1963). These workers have observed normal meiosis.…”

“…It would be interesting to know any other developments aiding pollen degeneration in such plants with specific cytoplasm and nuclear genes. Thus Ernst Artswager (1947) in sugar beet and Singh and Hadley (1961) in m . s. C. K. 60 have reported the specific role of tapetum layer in the anther sacs of male sterile plants .…”

“…While studying the stage of pollen grain degeneration in male sterile grain 'Sorghum', Maunder and Pickett (1959) have reported that meiosis in the male sterile grain Sorghum appeared to be normal, but after the pollen grains were partially formed they tended to shrivel and the anthers reduced in size and lacked viable pollens prior to dehiscence. Singh and Hadley (1961) …”

A comparative study on anther development in male-fertile and male-sterile plants of Pelargonium crispumL'Her. ex Ait.

“…Therefore, it may be thought that the tapetum disintegrated in connection with the formation of the exine not only in the fertile anthers but also in the sterile ones. Many reports have been published in which male sterility was closely related to the abnormal behaviour of the tapetum: e.g., the lack of tapetum (TOKUMASU, 1957), the premature degeneration of tapetum (IWAMASA, 1966), the delay of tapetal disintegration (SINGH & HADLEY, 1961), the discrepancy of growth rates between microspores and tapetum (NIsHI & HIRAOKA, 1958), the morphological change of tapetum (NISHI 8Z HIRAOKA, 1958), the weak staining of cytoplasm and the frequent occurrence of endomitosis in tapetum (SINGH HADLEY, 1961), the hypertrophy of tapetal cells (NISHI t~;H1RAOKA, 1958), and the formation of periplasmodium in originally glandular tapetum (ARTsCI-tWAGER, 1947). In these cases, it is not always easy to determine whether tapetal abnormality gives rise to the abortion of microspores, or whether abnormal microspore development affects the behaviour of the tapetum.…”