三系杂交稻稻瘟病抗性与产量的配合力分析

Analysis of Combining Ability of the Rice Blast Resistance and Yield in Three-line Indica Hybrid Rice

为了阐明三系杂交稻稻瘟病抗性和产量之间一般配合力(GCA)、特殊配合力(SCA)的遗传效应,揭示二者间的关联性。本研究以6个三系野败型不育系和13个恢复系配制的78个杂交稻组合为材料,进行田间自然抗性鉴定,于稻瘟病盛发期调查各组合叶瘟、穗瘟、稻穗损失率,成熟期测定单株产量。配合力方差分析结果表明:稻瘟病抗性和单株产量均受亲本基因的加性效应和非加性效应的共同影响,但非加性效应高于加性效应,而且恢复系GCA基因型方差的贡献率大于不育系;稻瘟病抗性和单株产量受遗传变异效应影响较大;GCA效应分析表明,不育系L5A和恢复系LR7、LR10均为正效应,不育系的穗瘟和穗瘟损失率之间为差异极显著正相关,恢复系稻瘟病3指标间为差异极显著正相关,单株产量与稻瘟病抗性间未达到显著相关性;SCA的效应分析表明,L2A/LR1、L3A/LR13、L4A/LR10、L4A/LR13、L5A/LR4、L5A/LR11、L6A/LR1稻瘟病抗性指数和单株产量均为正效应,杂交稻组合稻瘟病3指标间为差异极显著正相关,而单株产量与稻瘟病抗性间为差异显著或极显著负相关。因此,抗病高产三系杂交水稻应选育GCA较高的亲本,同时注意协调组合的SCA。

In order to elucidate the genetic effects of parental GCA and F1 SCA on the rice blast and yield per plant of the indica hybrid rice, 78 combinations of indica hybrid rice from 6 new wild-abortive male sterile lines in the three-line system and 13 restorer lines were selected to identify their rice blast resistance in the field. The leaf blast, panicle blast, panicle blast loss rate were observed during the peak period of the rice blast, and the rice yield per plant was measured at the mature stage.The variance analysis of combining ability showed that the inheritance of the rice blast indexes and yield per plant were all affected by both the additive and non-additive effects of the parental genes and that the non-additive effect of the parental genes was higher than the non-additive effect of the parental genes. The general combining ability(GCA) variance of the restorer lines was higher than that of the male sterile lines. The resistance to rice blast and the yield per plant were more affected by genetic variance. The GCA effect analysis showed that the sterile line L5A and the restorer lines LR7 and LR10 had positive effect. The sterile line was highly significantly positively correlated with panicle blast and rate of panicle blast loss;the restorer lines had a highly significant correlation among the three indices of the rice blast;and the rice yield per plant was not significantly correlated with resistance to the rice blast. Specific combining ability(SCA) analysis showed the hybrid rice combinations L2A/LR1, L3A/LR13, L4A/LR10, L4A/LR13, L5A/LR4, L5A/LR11 and L6A/LR1 had positive SCA effects on the rice blast resistance indexes and the yield per plant. The leaf blast, panicle blast and rate of panicle blast loss were highly significantly negatively correlated in these combinations, and the yield per plant had a highly significantly negative correlation with the leaf blast, and a significantly negative correlation with the panicle blast or panicle blast loss rate. Therefore, parents with high GCA should be selected to develop indica hybrid rice with high disease resistance and yield in the three-line system,and the SCA of the crosses should also be considered.