籼型染色体置换片段在杂交粳稻中的配合力分析

利用10个以粳稻为遗传背景、籼稻为供体的染色体片段置换系(CSSL)及6个粳稻测验种, 按NCII设计, 分析了籼粳亚种间杂种在10个染色体区段上的配合力效应及遗传力等参数。结果表明, 除千粒重外, 各置换系主要产量构成性状的GCA值均高于背景亲本Asominori, 其中带有第12、第4、第1和第11染色体片段的AIS84、AIS27、AIS3、AIS80和AIS76置换系产量相关性状的GCA综合表现最好。说明在染色体片段水平上, 水稻籼粳亚种主要产量构成性状的杂种优势都大于粳亚种内的杂种优势, 对粳稻基因组导入籼稻X24-2~R367 (Chr.12)、R1854~R288 (Chr.4)、C970~C955 (Chr.1)、C1350~R257 (Chr.11)和X52~R2913 (Chr.11)染色体片段, 可显著提高杂交粳稻的产量水平。同一亲本所配的不同组合及同一组合在不同性状间的特殊配合力差异较大, 最高或最低SCA的组合可来自不同GCA的亲本组合类型, 表明在一般配合力与特殊配合力间不存在必然的联系。在双亲一般配合力均高的前提下结合较高的特殊配合力是超高产杂交稻育种中亲本选择的基本原则。

Combining Ability of Yield-Component Traits for Indica Chromosome Substituted Segments in Japonica Hybrids

NC II(10´6) experiment derived from crossing between 10 indica-japonica chromosome segment substitution lines (CSSLs) with uniform japonica genome background and 6 japonica testers was conducted to analyze GCA, SCA, and relative genetic parameters of target chromosome segments. The GCAs of 10 CSSLs in main yield-component traits except 1000-grain weight were higher than those of background parent. CSSLs AIS84, AIS27, AIS3, AIS80, and AIS76 with chromosome substitution segments respectively from chromosomes 12, 4, 1, 11, and 11 ranked the top 5 in GCA of yield-related characters. The results indicated that heterosis of main yield-component traits in indica/japonica combinations at chromosome segment level was much stronger than that of typical japonica hybrid rice and intentionally substituting japonica chromosome segments with indica coun-terparts of X24-2–R367 (Chr. 12), R1854–R288 (Chr. 4), C970–C955 (Chr. 1), C1350–R257 (Chr. 11), and X52–R2913 (Chr. 11) could significantly upgrade yield potential of japonica hybrid rice. The SCA of different combinations with one same parent or different traits in the same combination had significant difference and the combinations with top SCA or bottom SCA could be derived from different parental GCA groups, which show that there is no causal relation between SCA and parental GCA. High GCA combining with strong SCA is a basic principle of parent selection in super-high yield hybrid rice breeding.