Dynamic QTL analysis of dry matter accumulation in soybean seed at different developmental stages | 不同发育时期大豆籽粒干物质积累的QTL动态分析

Chinese. 【目的】在不同发育时期,探索影响大豆籽粒干物质积累QTL的加性效应、上位性效应和环境互作效应及其对大豆籽粒干物质积累的影响,可加深大豆育种工作者对产量形成的理解和加速育种进程。【方法】以美国大豆品种Charleston为母本,东农594为父本及二者杂交所得F5所衍生的143个F5:9、F5:10和F5:11重组自交系为研究材料,研究不同发育时期控制大豆籽粒干物质积累的QTL及其遗传效应对大豆籽粒干物质积累的影响。【结果】在不同发育时期检测到与大豆籽粒干物质积累相关的13个加性QTL和14对上位性QTL,其中8个加性QTL和8对上位性QTL存在与环境互作效应。另外,在本研究中仅有加性QTL dmaC2_2能够在6个发育时期都被检测到,而其它加性QTL和14对上位性QTL只能在某个或某些时期被检测到。【结论】在6个不同的发育时期,加性QTL数目、加性QTL能够解释的表型变异呈现“S”型曲线变化,与大豆籽粒干物质重的表现型变化相似,而上位性QTL能够解释的表型变异相对稳定且较小。从效应值上看,加性效应在籽粒发育开始（30 d发育时期）较大,从40 d发育时期开始降低,在70 d发育时期降至最低,在籽粒发育结束时（80 d发育时期）略有上升;上位性效应从30 d发育时期到70 d发育时期一直上升,在籽粒发育结束时（80 d发育时期）略有下降;QTL×环境互作效应在6个发育时期均显著地影响大豆籽粒干物质的积累。从连锁群的位置上看,在6个不同的发育时期控制大豆籽粒干物质积累的加性QTL主要集中在C2连锁群（从OPK14_70到satt134区间,即QTL dmaC2_1、dmaC2_2、dmaC2_3所对应的区间）,特别是发育初期（30 d发育时期）;从40 d发育时期到籽粒发育结束时（80 d发育时期）,控制大豆籽粒干物质积累的加性QTL的连锁群位置变化较多,表现为发育时期的选择性。在6个不同的发育时期中,除50 d发育时期以外,控制大豆籽粒干物质积累的上位性QTL主要集中在C2连锁群（从OPK14_70到satt202区间,即QTL dmaC2_1所对应的区间）和D1b连锁群（从satt537到sat_135区间,即QTL dmaD1b_1所对应的区间）之间。

English. 【Objective】 To explore the additive (A), epistatic (AA) and quantitative trait locus (QTL) ×environment interaction effects (QE) of QTL on dry matter accumulation of soybean seed for deepen understanding the nature of the yield formation and accelerating the breeding process. 【Method】 The aim of the present study was to measure A, AA and QE effects of QTL on dry matter accumulation in a population of 143 F5:9,F5:10 and F5:11 derived recombinant inbred lines developed from the cross between the soybean cultivars Charleston and Dongnong 594. 【Result】 Thirteen QTLs with A effect were detected at different developmental stages, eight of which had significant additive × environment (AE) effect. Fourteen AA pairwise QTLs were found, eight of which showed significant epistatise × environment (AAE) effect. Furthermore, only dmaC2_2, QTL with A effect could be found from 30 day to 80 day developmental stage, other QTLs with A effect and 14 AA pairwise QTLs were only found at some developmental stages. 【Conclusion】 The number of QTL with A effect and phenotypic variation explained by QTL with A effect, present “S” curve from 30 day to 80 day developmental stage, which was similar to phenotypic variation of dry matter accumulation of soybean seed. However, phenotypic variation explained by these AA pairwise QTLs was relatively stable and small. Additive effect, being high in 30 day developmental stage, decreased from 40 day to 70 day developmental stage, rising at 80 day developmental stage. Epistatic effects continuously rised from 30 day to 70 day developmental stage, slightly declined at 80 day developmental stage. QTL×environment effect had a greater impact on the dry matter accumulation of soybean seed from 30 day to 80 day developmental stage. QTL with additive effect, mostly located in linkage group C2 (the interval from OPK14_70 to satt134, corresponding to QTL including dmaC2_1, dmaC2_2 and dmaC2_3 ) at six developmental stages, especially at 30 day developmental stage. Loci of linkage group of QTL with additive effect had most change from 40 day to maturity, which had selectivity at developmental stage. QTL with epistasis effect, mostly located between linkage group C2 (the interval from OPK14_70 to satt134, corresponding to QTL dmaC2_1) and linkage group D1b (the interval from satt537 to sat_135, corresponding to QTL dmaD1b_1) at most developmental stages, except for 50 day developmental stage.