CALCIUM DISTRIBUTION IN FERTILE AND STERILE ANTHERS OF A PHOTOPERIOD-SENSITIVE GENIC MALE-STERILE RICE

Potassium antimonate was used to locate Ca2+ in fertile and sterile an thers of a photoperiod-sensitive genic male-sterile rice (Oryza sativa L. japonica). During the development of fertile anthers, abundant cal cium precipitates accumulated in the anther walls and on the surface o f pollen grains and Ubish bodies at the late developmental stage of th e microspore, but not in the cytoplasm of pollen grains. Following the accumulation of starch grains in pollen, calcium precipitates on poll en walls diminished and increased in parenchymatous cells of the conne ctive tissue. In sterile anthers, calcium precipitates were abundant i n the middle layer and endothecium, but not in the tapetum, as was fou nd in fertile anthers. A special cell wall was observed between the ta petum and middle layer of sterile anthers that appeared to relate to d istinctive calcium accumulation patterns and poor pollen wall formatio n in the loculi. The formation of different patterns of antimonate-ind uced calcium precipitates in the anthers of photoperiod-sensitive geni c male-sterile rice indicates that anomalies in the distribution of ca lcium accumulation correlate with the failure of pollen development an d pollen abortion.