大豆定向选择群体耐旱性位点基因型分析及QTL定位

利用Clark导入到红丰11为背景的回交导入系进行萌芽期和苗期的连续性耐早鉴定，经萌芽期鉴定，获得36个耐旱定向选择导入系。对耐旱选择导入系进行全基因组SSR标记扫描，并以随机群体作为对照，计算供体基因型的导入频率，利用卡方测验检测显著偏分离的SSR标记位点，并结合GGT图示基因型软件对各染色体连锁群进行分析。其中在L连锁群的Satt398和Satt156两个位点有显著的供体片段“超导入”现象，供体基因型导入频率为0．9167和0．9583，卡方值高达182和201．5。另外，在F连锁群的Satt423，K连锁群的Satt167以及N连锁群的Sat_084等位点也出现供体导入片段的偏分离现象。同时，对萌芽期耐早鉴定中相对发芽率表现超亲的35个株系采用性状-标记间的单向方差分析（P〈0．01）和QTL定位，共检测到14个控制相对发芽率的QTL，分布在4个连锁群上，其中与卡方测验检测的结果相比较，在Satt156，Satt423，Sattt167等位点具有一致性，说明这些位点是与大豆耐旱性紧密相关的QTL位点。以上结果为进一步开展大豆耐旱性有利基因的精细定位、克隆和分子设计育种奠定了基础。

Genotype and QTL analysis of drought tolerance loci for directional population in soybean

Soybean is grown worldwide where many areas are under drought stress. The drought tolerance （DT） becomes a very important trait. Previous studies have identified many QTLs associated with DT and its related traits, but there was little research on the genotype analysis. In order to obtain more useful DT material and find out related steady and repeatable QTLs, a primary backcross introgression lines （ILs） were constructed with Hongfeng 11 as recurrent parent and Clark as donor parent. 35 drought tolerance introgression populations were screened from 72 BC1F3 populations using germination screening. Then 36 individuals from 11 super introgression populations were obtained after seedling screening. Comparing with the random population, which were selected from the same generation of ILs, the whole genome SSR markers and calculation for the frequency of donor genes segments had been analyzed with the 36 DT directional populations. In addition,Ⅹ^2 test and GGT analysis for the genotypes had also been computed. There were excessive introgression of Satt398 and Satt156 in L linkage group,with the frequency of donor genes were 0.916 7 and 0. 958 3 ,respectively,and the values of Ⅹ^2 were 182 and 201.5, respe-etively. The same were Satt423 in F linkage group, Satt167 in K Linkage group,and Sat_084 in N Linkage group. The QTL identification of the relative germination index was conducted by one - way ANOVA （ for single marker a nalysis, P 〈0.01 ） with the 35 DT introgression populations. 14 QTLs in 4 linkage groups for relative germination rate were investigated. Comparing with the results of Ⅹ^2 test, there were many consistent QTLs including Satt156, Satt423 ,Sattt167. It was proved that these loci were associated with DT of soybean. The results above would be a good foundation in fine mapping, cloning and molecular breeding of favorable genes related to DT in soybean.