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高温热害是水稻生产的重要制约因素之一。本研究利用籼稻恢复系蜀恢527为轮回亲本,以来自不同来源的6个籼稻品种为供体亲本构建了131个BC2F3:4选择导入系群体,在正常大田和温室大棚高温胁迫条件下进行连续两年(2011年和2012年)的耐热性鉴定,并结合基因型分析进行产量相关性状和耐热性QTL定位。耐热表型分析结果表明,尽管轮回亲本和供体本身不具备很强的耐热性,但绝大多数导入系后代出现了耐热性的超亲分离。本研究通过分子标记基因型和表型分析的单向方差分析进行产量相关性状(每穗总粒数,结实率,千粒重,单株产量)和耐热性(热胁迫指数)QTL发掘,共定位的到39个产量相关性状QTL,贡献率为7.3%~39.7%和12个耐热性QTL,贡献率为14.7%~30.2%。12个耐热性QTL中,有9个也在产量相关性状中检测到。40例QTL有利等位基因来自供体亲本,61.5%的QTL能在不同群体或环境中被重复检测到。产量性状和耐热性QTL在染色体上大多成簇分布,每个簇往往同时影响几个性状(多效性)。其中,第2染色体上RM341(Bin2.8)对每穗总粒数、千粒重和单株产量影响较大;第7染色体RM051(Bin7.1)则是主要控制结实率、单株产量和耐热指数等性状。第10染色体RM258(Bin10.5)则是主要控制每穗总粒数和耐热指数等性状。研究结果将为水稻耐热性改良及其分子标记辅助育种提供有益信息。
High temperature heat damage is one of the important constraints of rice production. In this study, 131 BC2F3: 4 selection inbred lines were constructed from six indica rice varieties from different provenances using the indica restorer line Shuhui 527 as a recurrent parent, and were continuously cultured under the conditions of high temperature in normal fields and greenhouses Two years (2011 and 2012) of heat resistance identification, combined with genotypic analysis of yield-related traits and heat-resistant QTL mapping. Thermotolerant phenotype analysis showed that although the recurrent parents and donors themselves do not possess strong heat tolerance, most of the progenies introduced into the progenies have thermophilic super-pro-segregation. In this study, QTLs for yield-related traits (total grain number per panicle, grain yield per plant, grain weight per plant, yield per plant) and heat tolerance (heat stress index) were excised and colocalized by one-way analysis of variance using molecular marker genotypes and phenotypic analysis To QTLs for 39 yield-related traits, accounting for 7.3% -39.7% and 12 QTLs with contribution rates ranging from 14.7% to 30.2%. Nine of the 12 heat-resistant QTLs were also detected in yield-related traits. Forty QTL favorable alleles were from donor parents, and 61.5% of QTLs could be repeatedly detected in different populations or environments. QTLs for yield traits and heat tolerance are mostly clustered in chromosomes and each cluster often affects several traits simultaneously (pleiotropy). Among them, RM341 (Bin2.8) on chromosome 2 had a significant effect on the total grain number, 1000-grain weight and yield per plant. On chromosome 7 RM051 (Bin7.1), the main control seed setting rate, yield per plant and heat tolerance Index and other traits. Chromosome RM258 (Bin10.5) is the main control of total grains per panicle and heat-resistant index and other traits. The results will provide useful information for rice thermotolerance improvement and its molecular marker-assisted breeding.