水稻细胞质雄性不育系裂颖种子的穗上分布规律研究

Distribution of Dehiscent Seeds on the Panicles of Cytoplasmic Male Sterile Lines in Rice

对4个具有不同裂颖特性的水稻细胞质雄性不育系及其保持系的种子裂颖率和4个不育系种子裂颖粒在穗上的分布特点进行了研究。结果表明:保持系种子裂颖轻于不育系,不育系与相应保持系的种子裂颖率呈显著正相关。不育系种子裂颖与同穗颖花开放的迟早有关,开花迟,裂颖率高;强势穗裂颖轻于弱势穗;一次枝梗轻于二次枝梗;穗上部轻于中部,中部轻于下部;一次枝梗第6粒位裂颖最轻,第2粒位相对较重;强势粒轻于弱势粒。

The percentages of dehiscent seeds, i. e. , the seeds with unclosed or dehiscing glume, of four pairs of cytoplasmic male sterile and maintainer lines with different extent of seed dehiscence and the distribution of dehiscent seeds on the panicles of the four male sterile lines were studied. The results showed that the seed dehiscence of the maintainer lines was lighter than that of the male sterile lines, and there existed a significant positive correlation between the percentages of dehiscent seeds of the male sterile lines and those of their corresponding maintainer lines. The extent of seed dehiscence on the same panicle of the male sterile lines was related to the order of spikelet opening, and a later opening of spikelets resulted in a higher percentage of dehiscent seeds. The percentage of dehiscent seeds of superior panicles was lower than that of inferior panicles; that of the primary branches was lower than that of the secondary branches; that of the upper positioned seeds on the panicles was lower than that of the middle positioned ones, and the latter was lower than that of the lower positioned ones; that of the sixth seeds was the lowest and the second seed was relatively higher on the same primary branch; and that of superior grains was lower than that of inferior grains.