大豆耐旱选择群体QTL定位

QTL Identification of Drought Tolerance to Soybean in Selection Population

以红丰11为轮回亲本、Clark为供体亲本构建回交群体进行耐旱性鉴定,对获得选择群体进行全基因组SSR标记扫描,计算供体基因型导入频率,利用卡方测验检测偏分离SSR位点,并结合GGT软件对各连锁群分析,对5个耐旱相关性状进行QTL定位。以卡方测验检测到23个SSR偏分离位点(超导入),分布于10条连锁群。方差分析表明,8个叶片持水能力QTL分布于A1、B1、C2、E、L和N连锁群;9个根长QTL分布于C2、F、G和I连锁群;11个根干重QTL分布于A2、B1、B2、E、F、K、L、M和O连锁群;12个产量QTL分布于B1、D1a、E、F、G、I、L、M和O连锁群;7个生物量QTL分布于E、F、G、K、L和N连锁群。在E连锁群的Sat_136位点,对于叶片持水能力、根干重、产量和生物量具有一致性;在F连锁群的GMRUBP位点,对于根干重和生物量具有一致性,Satt586位点,对于根长、根干重和产量具有一致性;在K连锁群的Satt167位点,对于根干重和生物量具有一致性,SOYPRP1位点,对于根长和生物量具有一致性;在L连锁群的Satt398位点,对于根长和产量具有一致性,Satt694位点对于叶片持水能力和生物量具有一致性;在M连锁群的GMSL514位点,对于根干重和产量具有一致性;以上位点均与卡方测验检测到的"超导入"位点具有一致性。经过供体等位基因卡方测验和耐旱QTL定位,共检测到33个QTL,其中有17个同时被检测到。这些位点可能是控制大豆耐旱性的重要位点。

A primary backcross introgression of soybean population was constructed by using Hongfeng 11 as recurrent parent and Clark as donor parent. After screening under drought stress, the genotypes of selective population were obtained with the whole genome SSR markers, and the frequency of donor genes segments were analyzed. QTLs of five drought-tolerance traits were mapped by Chi-test combined GGT linkage group analysis. In total, 23 SSR excessive introgression loci on 10 chromosomes were detected with χ2 test. The QTL identification was conducted by one-way ANOVA （for single marker analysis, P0.01）. Eight QTLs of RWC （relative water content） were located on A1, B1, C2, E, L, and N linkage groups, nine QTLs of RRL （relative root length） on C2, F, G, and I linkage groups, 11 QTLs of RRW （relative root dry weight） on A2, B1, B2, E, F, K, L, M, and O linkage groups, 12 QTLs of RGY （relative grain yield） on B1, D1a, E, F, G, I, L, M, and O linkage groups and seven QTLs of RMB （relative microbial biomass） on E, F, G, K, L, and N linkage groups. The QTL at Sat_136 on E linkage group was identical for RWC, RRW, RGY, and RMB, and QTL at GMRUBP on F linkage group for RRW and RMB, QTL at Satt586 on F linkage group for RRL, RRW, and RGY, QTL at Satt167 on K linkage group for RRW and RMB, QTL at SOYPRP1 on K linkage group for RRL and RMB, QTL at Satt398 on L linkage group for RRL and RGY, QTL at Satt694 on L linkage group for RWC and RMB, QTL at GMSL514 on L linkage group for RRW and RGY. All above QTLs were coincident with those detected by excessive introgression of χ2 test. Thirty-three QTLs were mapped by χ2 test or one-way ANOVA, and among them 17 QTLs were detected by both methods. So these QTLs should be essential for drought tolerance. The results provide a foundation for fine mapping, cloning and molecular breeding of favorable genes related with drought tolerance.