不同营养水平水培条件下幼苗期大豆下胚轴性状QTL定位与上位互作分析

Identification of Quantitative Trait Loci and Epistatic Interactions for Seedling Hypocotyl Taits in Soybean Under Different Hydroponic Culture Nutrition Level

为探究不同氮磷钾水平对大豆幼苗期下胚轴性状的影响,发掘其基因资源,了解其遗传机制,本试验以栽培大豆晋豆23为母本,以山西农家品种灰布支黑豆为父本及其所衍生的447个重组自交系(RIL)为材料,设置3个处理:CK(模拟种植不施肥)、T1(模拟大田正常配施氮磷钾肥)和T2(模拟高肥田块,含量为大田常规配施氮磷钾肥的1.5倍),研究不同营养水平水培条件下幼苗期大豆QTL间的上位性和环境互作效应。结果表明,基于复合区间作图(CIM)共检测到20个影响下胚轴长和下胚轴重的QTL,分布于第2、第6、第7、第8、第9、第10、第13、第16、第20共9条染色体上,单个QTL的贡献率介于3.65%~18.13%之间。基于混合线性模型(MCIM)检测到3对下胚轴长上位互作QTL,2对下胚轴重上位互作QTL,5对QTL均发生在2个非主效QTL之间。第9和第10染色体分别在3种处理中同时检测到下胚轴长和下胚轴重QTL,表明加性效应、加性与环境互作效应和加性×加性上位性互作效应在下胚轴长和下胚轴重的形成和遗传中起重要作用。本研究为大豆幼苗期下胚轴性状的QTL定位、图位克隆和分子标记辅助选择以及为实际生产中苗期施肥时间的选择和氮磷钾高效利用提供了一定的理论参考。

In order to study hypocotyl trait under different NPK conditions at seedling stage in soybean,and dig gene resources and reveal the genetic mechanisms. A set of 447 recombinant inbred line（ RIL） derived from a cross between Jindou23（ cultivar,female parent） and ZDD2315（ semi-wild,male parent） was used as materials in this study.Epistatic QTL effects and QTLx enviroment interactions were identified in soybean under three treatments： CK（ nonfertilized condition）,T1（ normal NPK fertilization conditions） and T2（ high fertilization conditions of 1. 5 NPK）.The results showed twenty QTLs for hypocotyl length and weight were detected on 9 chromosomes of 2,6,7,8,9,10,13,16 and 20 using composite interval mapping（ CIM） method in this study; the variations accounted for by one signle QTL ranged from 3. 65% to 18. 13% . Three and two pair of epistatic QTLs for hypocotyl length and weight was detected respectively non-major QTLs by Compressed mixed linear model（ MCIM）. The 9 and 10 chromosome contained some QTLs for hypocotyl length and weight in three treatments,and showed that additive effects,additive × environment interactions effects and additive × additive epistatic effects are important genetic factors for hypocotyl length and weight formation and inheritance. The results will give a significant reference for hypocotyl traits QTL mapping,map-based cloning and marker-assisted selection in soybean at the seedling stage,and provide theoretical guidance to fertilization time at seedling stage in soybean and NPK use efficiency in the practical production.