大豆叶片性状和叶绿素含量QTL间的上位性和环境互作效应

以丰产性好、抗旱力强的栽培大豆晋豆23为母本,山西农家品种半野生大豆灰布支黑豆为父本杂交衍生的447个RIL作为供试群体。将亲本及447个家系分别于2011、2012和2013年采用随机试验种植,按照标准测量叶长、叶宽和叶柄长3个性状,并于2012年8月1日和8月8日和2013年8月2日和8月9日各测量1次叶绿素含量。采用QTLNETwork 2.0混合线性模型分析方法和主基因+多基因混合遗传分离分析法,对大豆叶片性状和叶绿素含量进行遗传分析和QTL间的上位性和环境互作效应研究。结果表明,叶长受2对加性-加性×加性上位性混合主基因控制,叶宽受3对等效主基因控制,叶柄长受4对加性-加性×加性上位性主基因控制,叶绿素含量受4对加性主基因控制;检测到10个与叶长、叶宽、叶柄长和叶绿素含量相关的QTL,分别位于A1、A2、C2、H_1、L和O染色体。其中2个叶长QTL分别位于C2和L染色体,是2对加性×加性上位互作效应及环境互作效应QTL;3个叶宽加性与环境互作QTL分别位于A2、C2和O染色体;2个叶柄长QTL分别位于L和O染色体;3个叶绿素含量QTL分别位于A1、C2和H_1染色体。叶片性状和叶绿素含量的遗传机制较复杂,加性效应、加性×加性上位互作效应及环境互作效应是大豆叶片性状和叶绿素含量的重要遗传基础。建议大豆分子标记辅助育种中,一方面要考虑起主要作用的QTL,另一方面要注重上位性QTL的影响,这对于性状的遗传和稳定表达具有积极的意义。

Epistatic and QTL × Environment Interaction Effects of QTLs for Leaf Traits and Leaf Chlorophyll Content in Soybean

A RIL population containing 447 lines, derived from a cross of cultivar Jingdou 23 × Huibuzhiheidou, as well as their parents were used to analyze inheritance and detect epistatic effects, and QTL × environment (QE) interactions related to leaf traits and leaf chlorophyll content (CC) in soybean using major gene plus polygene mixed inheritance analysis and composite interval mapping (QTL NETwork 2.0). The leaf traits including leaf length (LL), leaf width (LW), leaf stalk length (LSL) were evaluated in 2011, 2012, and 2013, as well as CC was detected on 1 August and 8 August, 2012, and on 2 August and 9 August, 2013. LL was found to be controlled by two pairs of additive-additive by additive epistatic hybrid main genes, LW was found to be controlled by three pairs of equivalent main genes, LSL was found to be controlled by four pairs of additive-additive by additive epistatic major genes, CC was controlled by four pairs of additive major genes. Ten QTLs for LL, LW, LSL, and CC were mapped on the linkage group (LG) A1, A2, C2, H_1, L, and O, separately. Of them two QTLs for LL were mapped on LG C2 and LG L, additive by additive epistatic effect and QE interactions. Three QTLs with additive effect and QE interactions associated with LW were mapped on LG A2, C2, and O. Two QTLs for LSL were mapped on LG L and O. Three QTLs for CC were mapped on LG A1, C2, and H_1. The genetic mechanism for leaf traits and leaf chlorophyll content is more complicated containing additive effect, additive × additive epistatic effect and QE interaction. It is important to consider not only to QTLs with major effects, but also to those with epistatic effects in soybean molecular marker-assisted breeding for stability of expression and inheritance of agronomic traits.