Abstract
The pollen fertility and the features of sterile spikelets in straighthead rice plants were Observed. The number of pollens per spikelet and the percentage of fertile pollens decreased obviously, and unequality in the size of pollens were found. As for the features of the sterile spikelets, non-flowering, unfertilization or the abortion of kernel occurred at the early ripening stage. The enlargement of some ovaries in sterile spikelets, i.e., parthenocarpylike ovaries, occurred so often. It was concluded that the sterility of straighthead plants was caused by some unknown obstacles during the growth stages of rice plants from pollen formation to the early stage of ripening.
