大豆导入系群体芽期耐低温位点的基因型分析及QTL定位

Genotype Analysis and QTL Mapping for Tolerance to Low Temperature in Germination by Introgression Lines in Soybean

利用美国大豆品种Clark(供体亲本)与主栽品种红丰11(轮回亲本)所构建的回交导入系,经过严格的芽期耐低温筛选鉴定,得到46个在芽期耐低温性状上明显超过轮回亲本的导入系个体。利用这套选择群体结合随机对照群体和基因型分析,通过基于遗传搭车原理的卡方分析和单向方差分析方法,检测到分布于大豆8个连锁群的12个与大豆芽期耐低温相关的QTL。其中卡方分析检测到9个供体片段的超导入位点,对芽期耐低温性状表现为正效应。方差分析检测到5个位点,也表现为正效应,且其中Satt237和SOYPRP1两个位点是两种方法共同检测到的,应视为与耐低温直接相关的QTL。本研究旨在创建大豆芽期耐低温分子育种的检测方法平台,为大豆芽期耐低温研究提供有用的分子标记。

Northeast of China is the main soybean production area. Low temperature is one of the main factors to reduce soybean yield and to limit soybean production spreading to north regions. Shortening the growth stage is considered as one way of solving the problem, but the effective way is to breed cultivars with low temperature to tolerance. The identification of low-temperature tolerance germplasm is the basis for soybean breeding. A set of backcross introgression lines were constructed with Hongfeng 11 as recurrent parent and Clark as donor parent, 46 individuals were screened out, which were more tolerant than recurrent parent Hongfeng 11 under low temperature condition. Fifty individuals from BC1F4 were used as control （random population）. Twelve QTLs on eight linkage groups for tolerance to low temperature in germination were detected with genotype analysis by chi-test and one-way ANOVA. Nine excessive-introgression alleles from donor parent with positive effect were acquired by chi-square and 5 alleles by ANOVA. Satt237 and SOYPRP1 were detected by the two methods, so the two loci should be the main effect QTL and more believable. Introgression lines were used for mapping QTL related with tolerance to low temperature in germination, and the molecular mechanism could be studied in the further research on the platform established in this study for molecular assisted breeding.