利用ILP标记分析水稻籼粳杂交亲本和衍生系的籼粳分化

Analysis of Indica-japonica Differentiation in Rice Parents and Derived Lines Using ILP Markers

【目的】揭示水稻籼粳杂交亲本和衍生系的籼粳分化度,为培育实用型籼粳亚种间杂交稻提供理论和实践依据。【方法】以通过不断聚合和累加不同广亲和基因与恢复基因的方法,历时21年,4个育种阶段,涉及18个籼粳杂交亲本和39个衍生系为研究材料,采用籼粳特异ILP分子标记(水稻内含子长度多态性分子标记)和程氏形态指数法进行籼粳分化度检测。【结果】57个供试材料基因组DNA在所检测位点上均存在籼粳分化。18个亲本共检测出4个粳稻、5个偏粳、8个偏籼和1个籼稻类型。在18个亲本中,明恢63和9308的粳稻成分分别为12.50%和33.33%;粳型恢复系C418的粳稻成分仅有31.25%。39个籼粳杂交衍生系共检测出1个粳稻、11个偏粳、20个偏籼和7个籼稻类型。其中,粳型衍生系明恢502的粳稻成分仅占10.42%。ILP标记法与形态指数法判定籼粳分类结果的吻合度较好,粳稻成分指数、籼稻成分指数与程氏指数综合值的相关系数分别为r=0.794**和r=-0.7662**。【结论】ILP标记具有准确检测籼(粳)成分比例的功能;研究籼粳分化可以合理解释籼粳型恢复系配组的杂交稻表现明显杂种优势的原因,对有效利用籼粳亚种间优良基因具有重要作用。

【Objective】 Revealing the Indica-Japonica differentiation in parents of hybridization between Indica and Japonica rice and their derived lines can provide theoretical and practical bases for the breeding of practical inter-subspecific hybrid rice. 【Method】Using subspeeies-speeific molecular markers ILP （Intron Length Polylnorphism） and Cheng＇s Index,the indica-japonica differentiation was analyzed with special materials including 18 indica-japonica hybrid parents and 39 derived lines,which accumulated different wide compatibility and restoring genes by convergent cross method in twenty-one years spanning four breeding phases. 【Result】 The indica-japonica differentiation was detected on all tested loci in 57 materials. Among the 18 parental lines,four were japonica type,five japonicaclinous type,eight indicaclinous type and one indica type. The japonica proportion index in indica restorer lines Minghui63 and 9308 were 12.50% and 33.33%,respectively,while that in japonica restorer line C418 was only 31.25%. Among the 39 derived lines from indica–japonica hybridization,one was Japonica type,eleven japonicaclinous type,twenty indicaclinous type and seven indica type. The japonica proportion index in Minghui502 was only 10.42%. The results of indica and japonica classification by ILP molecular marker and Cheng＇s Index were relatively consistent. The correlation coefficient between the japonica proportion index and morphology index was 0.794^＊＊,while that between the indica proportion index and morphology index was -0.7662^＊＊【.Conclusion】 ILP marker could be used to accurately detect the proportion of indica/japonica content in the genome of a rice variety. The results of indica-japonica differentiation analysis could make reasonable explanation for that the hybrids obtained from indica-japonica type restorer lines had obvious heterosis. This conclusion would provide important guidance in efficient use of beneficial genes of inter-subspecific hybrid rice.