硅对水稻籼粳杂种雌雄配子育性和结实率的影响

以2个籼稻品种和2个粳稻品种及其籼粳杂种一代为材料,通过水培试验研究了硅对籼粳亚种间杂种雌雄配子育性和结实率的影响。结果表明:4个水稻亲本的育性正常,而亚种间杂种‘台中65’/‘广陆矮4号’和‘穞稻’/‘秋光’F1花粉育性分别为40.1%和50.3%,小穗育性分别为25.8%和40.3%;其F1胚囊具有正常的卵细胞、助细胞、极核及反足细胞,胚囊败育率分别为5.33%和3.33%。加硅处理F1每个柱头上花粉粒多于25粒的小花数分别占90%和90.5%,而不加硅处理高于20粒的小花数仅占8%和10%;加硅处理F1花粉离体萌发率分别为75.15%和76.23%,小穗的结实率分别达到65.5%和68.7%,而不加硅处理的分别为46.7%和48.13%,小穗结实率分别只有25.8%和40.3%,且加硅处理极显著高于不加硅处理。研究表明,水稻籼粳杂种存在半不育现象,并主要由花粉半不育和花药开裂性差造成;硅肥能促进杂种F1植株的花药开裂,明显增加柱头上花粉粒数目,并促进花粉萌发,显著提高小穗的结实率。

Effects of Silicon on Gametes and Spikelet Fertility of F_1 Hybrid between Indica and Japonica Rice

There was a semi-sterility in intersubspecific hybrids(’Taichung 65’×’Guangluai 4’ and ’Ludao’×’Qiuguang’).The effect of silicon on the fertility of female and male gametes as well as the seed-setting rate in intersubspecific hybrids was studied by water culture.The results were as follows:The fertility of four parents was normal,but that of the F1 hybrids were abnormal between indica and japonica rice.The pollen and spikelet fertility of ’Taichung65’×’Guangluai 4’ were 40.1% and 25.8%,respectively,and that of the’Ludao’×’Qiuguang’ were 50.3% and 40.3%,respectively.The embryo sac of the two F1 hybrids had one egg cell,two synergid cells and antipodal cells,as that of normal plants.The rates of the embryo sac abortion were 5.33%(’Taichung 65’×’Guangluai 4’) and 3.33%(’Ludao’×’Qiuguang’),respectively.The florets number of the pollen number larger than 25 on per stigma of F1 plants were 90%(’Taichung 65’×’Guangluai 4’) and 90.5%(’Ludao’ ×’Qiuguang’),and the pollen germination rates in vitro of F1 hybrids were 75.15%(’Taichung 65’×’Guangluai 4’) and 76.23%(’Ludao’×’Qiuguang’),and the seed-setting rates of F1 hybrids were 65.5%(’Taichung 65’×’Guangluai 4’) and 68.7%(’Ludao’×’Qiuguang’),respectively,by the utilization of silicon fertilizer.While,the florets number rates of the pollen number larger than 20 on per stigma of F1 plants were 8%(’Taichung 65’×’Guangluai 4’) and 10%(’Ludao’ ×’Qiuguang’),and the pollen germination rates in vitro of F1 hybrids were 46.7%(’Taichung 65’×’Guangluai 4’) and 48.13%(’Ludao’×’Qiuguang’),and the seed-setting rates of F1 hybrids were 25.8%(’Taichung 65’×’Guangluai 4’) and 40.3%(’Ludao’×’Qiuguang’),respectively,under control.There was significant difference between the control and silicon fertilizer treatment.Therefore,the semi-sterility was caused by pollens semi-sterility and the poor anther dehiscence in intersubspecific hybrids.Our findings demonstrate that the rate of anther dehiscence,the number of pollen per stigma of F1 plants,the potential of pollen grains germination and the fertility of spikelet could be significantly improved by the utilization of silicon fertilizer.