分子标记增效座位在不同生长环境下预测籼型杂交稻籽粒外观性状的效应

Effects of Molecular Marker Effect-increasing Loci on Predicting Grain Appearance Traits of Indica Rice Combination under the Different Growing Environments

以两套杂交水稻不完全双列组合(按NCⅡ设计)及其亲本为材料,在重庆和泸州两个环境条件下种植,利用SSR和AFLP技术分析32个亲本材料的1085个标记座位,并从这1085个标记座位中筛选出与F1粒形性状相关的阳性位点和增效位点,分别用此两类座位计算的遗传差异对F1谷粒、糙米和整精米的长、宽和厚共9个籽粒外形性状进行了预测。结果表明,增效位点的亲本遗传距离与相应F1粒形性状的相关系数在0.321￣0.892间,平均0.736,高于阳性位点的相关系数。对不同亲本组合(套间)的预测结果表明,增效位点的预测效果明显好于阳性位点,其预测值为0.138￣0.805,平均0.451,其中对谷宽、糙米宽和整精米宽预测值分别为0.704、0.707和0.654,达到了可预测水平。同一套组合在不同环境下(环境间)预测结果表明,增效位点的预测效果明显好于阳性位点,预测值平均达0.653,除谷厚、糙米厚和整精米厚外的6个粒形性状其预测值均在0.640以上,达到了可预测水平。部分性状在组合间和环境间达到可预测水平,这将为育种家们对这些性状进行早期选择具有一定指导意义。

Heterosis of F1 hybrid is closely correlative to genetic distances between their parents at certain extent. Study on predicting hybrid performances of shape traits of grain of hybrid rice （Oryza sativa spp. indica L.） would be more helpful to choose parents efficiently and to enhance the yield and quality of hybrid. In present research, 151 F1 hybrids were made by the designs of in two half-diallels sets （based on NC Ⅱ design） and 32 gernplams were employed as the parents to planted in two ecological sites （Chongqing and Luzhou）. The 1 085 polymorphic bands generated by SSR and AFLP for the 32 parents were recorded which used for loci-screening with F1 performances of nine shape traits of grain （length, width and thickness of grain, brown rice and head rice）, positive loci （PL） and effect-increasing loci （IL） were firstly obtained and applied to predict the hybrid performances of crosses with different parents under the different rice growing environments, respectively. The results showed the correlations between parental GD and corresponding F1 grain shape traits in two sets of combinations under two growing environments varied from 0.321 to 0.892, with a mean of 0.736, larger than those based on PLs. ILs were more effective than that of PLs on predicting hybrid performance of combinations with different parents in the same environment and with the same parents in different environments. The predicting result of ILs with different parents in the same environment showed that the predicting values of different traits varied from 0.138 to 0.805, with a mean of 0.451. Mean values of predicted effects of width of grain, brown rice, and head rice were 0.704, 0.707, and 0.654, respectively, which might present the feasibility in heterosis prediction. The mean value of predicted effects of ILs with the same parents in different environments was 0.653. All traits except thicknesses of grain, brown rice, and head rice, respectively, were fine predicted by ILs and the prediction values were above 0.640, further presented the feasibility in heterosis prediction. The predicting effects of some traits demonstrated the promising perspective in heterosis prediction, which would be helpful for rice breeders to improve the efficiency of breeding program.