VARIABLE STERILITY AND APOSPORY IN PEARL MILLET

Abstract

In inbred lines of pearl millet, one plant and its selfed progenies showed low and variable seed set in different spikes. Genetic analysis revealed the transmission of variable sterility through male gametes also. Meiosis in PMCs and pollen fertility were normal. However, plants with full seed set were not obtained in any of the segregating generations. Maternal (apomictic) plants were identified at different frequencies in progenies of crosses using genetic markers. In variable steriles, female gametophyte development showed variation within spikes, like (a) normal embryo sacs, (b) diminutive embryo sacs, and (c) multinucleate aposporous initials, one of which formed precocious embryo and endosperm. Studies after pollination with a fertile line also showed variations like (a) normal development of embryo and endosperm, (b) formation of undersized embryos, and (c) degeneration of embryo sacs.