Studies on partial male-sterility in rice plant.

Abstract

Under the particular cytoplasm (S) which is different from cytoplasm(N) of normal fertile rice plants, partial male-sberility can, in many casesbe monogenic recessive. S-cytoplasm seemed to be variable according to environmental conditions. Consequently it changes the rate of unfertilized spikelets under low temperature. Hypertrophied tapetum induced by low temperature in normal plants and that in partially male-sterile plant are similar and appear in pollen sacs in stages between the first contraction of microspores and pollen extme formation.