成恢448近等基因导入系的稻米延伸性分析

Study on cooked rice elongation(CRE) of near-isogenic introgression lines of Chenghui 448

对列入全球水稻分子育种计划的38个水稻供体品种及其与轮回亲本成恢448(CH448)不同回交后代的稻米延伸性(CRE)进行了测试和分析。因子分析结果表明,在38个供体亲本与轮回亲本CH448的BC3F2群体中,不同回交组合内稻米延伸性的变异有所不同;该世代各群体之间在CRE性状上的变异情况的不同之处,主要表现在主因子2(变异系数、最小值)和主因子3(平均值、最大值)上;这主要取决于亲本组合的不同;在这38个BC3F2群体中,CH4448分别与沈农365、冈46B和OM1706的亲本组合比较理想;选择适当的群体有利于CRE的QTLs聚合与遗传改良。在4个亲本(沈农365、x23、Palung 2和x22)分别与轮回亲本CH448的BC3F2、BC3F3以及Basmati370与CH448的BC2F3、BC2F4和BC2F5群体中,随自交世代的增加,CRE的变异趋势和幅度也随供体亲本不同而有所差异,CRE-QTLs聚合程度与供体亲本有较大关系;自交有利于CRE的QTLs进一步聚合;通过育种对稻米CRE进行遗传改良,需要选择适当的亲本,用轮回亲本与之连续回交,并结合自交使该性状的QTLs进一步纯合。讨论了通过回交方法聚合CRE有关QTLs和改良稻米CRE等蒸煮品质的育种策略。

The cooked rice elongation（CRE） of 38 core rice germpalsm listed in the Global Molecular Breeding Program and the progenies backcrossed with Chenghui 448（CH448, the recurrent parent） were tested and analyzed. The results of factor analysis showed that in the BC3F2 populations of 38 donors backcrossed with CH448, the variations of CRE were different within different backcrossed populations and also among different populations. It was decided by the donors and showed in factor 2 which was consisted of variation coefficient ＆ minimum, and factor 3 which was consisted of average ＆ maximum. Among the 38 populations, three combinations in which the donors were Shengnong 365, G46B and OM1706, were the ideal combinations for CRE improvement. It should be advantageous to select proper BC3F2 populations for the aggregation of CRE-QTLs and genetic improvement of CRE. In the BC3F2 ＆ BC3F3 populations of Shengnong365, x23, Palung2 ＆ x22 backcrossed with CH448, and the BCaF3, BCaF4 ＆ BC2F5 populations of Basmati370 backcrossed with the same recurrent parent, the variation trends and extents were different along with the different donors. The numbers of CRE- QTLs polymerized into the progenies backcrussed with the recurrent parent was related to the donors. Self-crosslng was benefit for the polymerization of CRE-QTLs, additionally. The suitable donors should be selected and backcrossed with the recurrent parent continuously for two to three generations, and adopted selfcrossing several times to polymerize and purify the QTLs of CRE in order to improve the CRE through rice breeding. The breeding strategy was discussed and proposed for the aggregation of CRE = QTLs and the improvement of the cooking quality including CRE through rice backcrossing breeding.