利用“永久F_2”群体进行小麦幼苗根系性状QTL分析  

Analysis of QTLs for Root Traits at Seedling Stage Using an "Immortalized F_2" Population of Wheat

作　　者：李卓坤[1] 彭涛[1,2] 张卫东[1] 谢全刚[1] 田纪春[1] 

机构地区：[1]山东农业大学国家作物生物学重点实验室小麦品质育种室,山东泰安271018 [2]济源市农业科学研究所,河南济源454652

出　　处：《作物学报》2010年第3期442-448,共7页Acta Agronomica Sinica

基　　金：国家重点基础研究发展计划(973计划)项目(2009CB118301)资助

摘　　要：为了研究小麦苗期根系性状的遗传,以小麦品种花培3号和豫麦57的杂交DH群体组配了一套含168个杂交组合的"永久F2"群体。利用WinRHIZO根系分析系统测定四叶一心期小麦水培幼苗根系总长度、直径、表面积、体积、根尖数、最大根长、茎叶干重、根干重及根茎干重比9个性状。采用复合区间作图法分析幼苗根系8个性状的QTL,定位了7个加性效应QTL和12对上位性互作QTL,包括加性效应、显性效应,加加互作、加显互作和显显互作,分布在1A、1D、2A、2B、2D、3A、3B、5D、6D和7D染色体上,单个QTL可解释0.01%～11.91%的遗传变异。在染色体2D上XWMC41至XBARC349.2区间检测到同时控制总根长和根干重的一个QTL。上位性对苗期根系生长发育有重要作用。试验结果表明,苗期根系性状的遗传机制较复杂,因此在育种中要综合考虑根系各性状之间的关系,保证根系协调统一、发达健壮。Identification of quantitative trait loci （QTLs） of roots plays an important role in the genetic mechanism study of root system. A number of QTLs for root traits have been detected using different populations in rice （Oryza sativa L.）, but rarely in wheat （Triticum aestivum L.）. The ＂immortalized F2＂ population is favorable for QTL analysis due to its similar proportions of genotypes in the population, and the replicability at multiple locations over several years. The objective of this study was to detect QTLs for several root traits at seedling stage in wheat. From a set of doubled haploid lines derived from Huapei 3 × Yumai 57, an ＂immortalized F2＂ population was constructed with 168 single crosses. Wheat seedlings were hydroponically cultured with Hoagland’s solution in a light incubator, and sampled when the fifth leaf emerged. Nine root traits including root total length, root surface area, root average diameter, root volume, root tips, maximum root length, shoot dry weight, root dry weight, and ratio of root dry weight to shoot dry weight per plant were measured using the WinRHIZO Root Analysis System. QTLs associated with the nine traits were detected using composite interval mapping （CIM） method. A total of seven additive QTLs and 12 pairs of epistatic QTLs were mapped on chromosomes 1A, 1D, 2A, 2B, 2D, 3A, 3B, 5D, 6D, and 7D. Additive, dominant and epistatic effects were observed across these QTLs, including the interactions between additive and additive, additive and dominance, dominance and additive, as well as dominance and dominance. The phenotypic variation explained by each QTL ranged from 0.01% to 11.91%. In the interval between XWMC41 and XBARC349.2 on chromosome 2D, a QTL for total root length and root dry weight was detected. Epistasis was of great importance in root growth and development at seedling stage in wheat. The results showed a complex mechanism on the genetics of root traits in wheat, and the eight root traits were significantly correlated with each other.

关 键 词：小麦 “永久F2”群体 根系性状 QTL定位 基因效应 

分 类 号：S512.1[农业科学—作物学]