水稻产量性状杂种优势的QTL定位

 【目的】利用QTL定位方法检测水稻产量性状杂种优势QTL,并解释杂种优势产生的可能分子机理。【方法】利用重组自交系与亲本协青早B构建BC1杂种群体,通过两地重复试验,以中亲优势考察6个产量性状的杂种优势表型,利用Windows QTL Cartographer 2.5的复合区间作图法检测其QTL。【结果】多数产量性状均表现出较强的杂种优势。在两地试验中,共检测到20个产量性状杂种优势QTL,分布在水稻第2、3、6、7、8、10等6条染色体上,包括3个控制单株产量杂种优势的QTL、2个控制单株穗数杂种优势的QTL、6个控制每穗总粒数杂种优势的QTL、4个控制每穗实粒数杂种优势的QTL、4个控制结实率杂种优势的QTL和1个控制千粒重杂种优势的QTL。单个QTL对群体性状表型变异的贡献率为4.90%—12.85%。【结论】检测到控制6个产量性状杂种优势的20个QTL,其中qHNP-3、qHTNSP-7、qHNFGP-7、qHSF-7、qHTGWT-3 5个QTL在两地试验中稳定表达;检测到的20个杂种优势QTL中,有13个与在RIL群体中检测到的QTL重叠,重叠率达65%,因此,认为来自纯系的产量性状加性效应对杂种优势产生具有重要贡献。

QTL Mapping for Heterosis of Yield Traits in Rice

【Objective】 In experiments, the heterosis QTL for yield traits was detected and the genetic basis of heterosis in rice was studied by method of QTL mapping. 【Method】 A backcross (BC1) population derived from XQZB/RILs was developed to observe the heterosis of six yield traits in two location trials. QTLs for six yield traits were determined using Windows QTL Cartographer 2.5 with composite interval mapping. 【Result】 Heterosis of majority yield traits were stronger. As the results indicated, a total of 20 significant heterosis QTLs for six yield traits were detected distributing on rice chromosomes 2, 3, 6, 7, 8, and 10, including three heterosis QTLs for grain yield (GYD) per plant, two heterosis QTLs for number of panicle (NP) per plant, six heterosis QTLs for total number of spikelet per panicle (TNSP), four heterosis QTLs for number of filled grain per panicle (NFGP), four heterosis QTLs for spikelet fertility (SF) and one heterosis QTL for 1000-grain weight (TGWT), respectively. The phenotypic variance explained by a single heterosis QTL ranged from 4.90% to 12.85%. 【Conclusion】 A total of 20 significant heterosis QTLs for six yield traits were detected and five heterosis QTLs among them were stable expression in two trials, included qHNP-3, qHTNSP-7, qHNFGPH-7, qHSF-7, qHTGWT-3. In the checked 20 heterosis QTLs, 13 of them were also checked in the RIL population, the degree of overlap were bigger up to 65%. It is suggested that additive effects also play an important role for yield heterosis.