Male sterile plants were obtained from S\5\ and S\6\ doubled haploid progenies
obtained after culturing anthers of F\1\ of the cross Co-40XVaigai and
diploidizing the resultant callus by colchicine. Whereas in one (ms-1), anthers
are highly reduced, in the other (ms-2), they are deformed and distorted to
varying degrees. Anther development in both the male steriles is abnormal. In
male sterile 1, male meiosis breaks down in early prophase I and in male
sterile 2, microspores degenerate after liberation from the PMC quartets.
Whereas, in the former, tapetal breakdown follows meiotic degeneration, in the
latter, it preceeds microspore abortion. Due to differential time and mode of
ms gene action, the two genes inducing male sterility appear nonallelic. In
each case, the sterility is controlled by one recessive ms gene. Allelism test
of the two recessive genes is in progress.