摘要:
六个早杂交稻组合的结实率存在着明显差异。用不育系V41A对它们的花粉进行测交。从测交F1植株育性分离情况统计分析表明,决定杂交稻种子育性的主要是恢复系两对恢复基因中的强恢基因R2的恢复力。威优35和威优057的结实率高是由于恢复力强的R2和弱恢的部分恢复基因R1的联合效应高的缘故。威优64中的R2对种子育性恢复力偏低,由于R2和R1的联合效应好,虽然结实率不够理想,其稳定性较好。威优437-1的结实率普遍偏低,其原因是由于恢复系437-1的两对恢复基因对花粉育性和种子育性恢复力都差,它的R2基因对种子育性恢复力弱是明显的。从可育花粉率大于50%的植株花粉育性和种子育性的相关系数来看,汕优菲一和威优3533的测交小区数值偏低,这两个杂交稻组合的结实率是不稳定的。选育恢复系要注意强恢源亲本的选择和两对恢复基因对杂种植株种子育性恢复的联合效应。
Abstract:
Six early-hybrid rice combinations were studied. They have been found, their seed-set rates were significantly different.These combinations were testcrossed with MS line V41A, and their F1 were observed and analysed about their fertile characters separately. The results indicated that fertility of hybrid rice mainly decided on strong one of two pairs of restorer genes (R2) and their "Synergism" in hybrid plant.For instance,the seed-set rates of Weiyou 35 and Weiyou 057 were higher, because their restoring abilities of the R2 were strong and the synergistic effects of two genes were high. In Weiyou 6 the fertility restoring ability of the R2 was low, but the "Synergism" of two restoring genes was satisfactory,therefore, its seed-set rate was stable. In Weiyou 437 the seed-set rate restoring effect of R2 was weak, and its seed-set rate was generally lowest. According to the correlation coefficient between the normal pollen rate and the seed-set rate, the testcrossing plots of Shanyouphi 1 and Weiyou 3533 were rather small, therefore, their seed-set rates were unstable. To sum up,in breeding strong restorer line we must emphasize the selection of strong restorer gene R2 and good "Synergism" between two restoring genes.
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