一个小麦强优势组合的杂种优势遗传基础解析  

Genetic basis of heterosis in a common wheat cross with strong-heterosis

作　　者：关攀锋 逯腊虎 刘刚 汪永法 辛明明 胡兆荣 姚颖垠 倪中福 孙其信 彭惠茹 Panfeng Guan;Lahu Lu;Gang Liu;Yongfa Wang;Mingming Xin;Zhaorong Hu;Yingyin Yao;Zhongfu Ni;Qixin Sun;Huiru Peng(Beijing Key Laboratory of Crop Genetic Improvement,Key Laboratory of Crop Heterosis and Utilization of Ministry of Education,State Key Laboratory for Agrobiotechnology,College of Agronomy and Biotechnology,China Agricultural University,Beijing 100193,China)

机构地区：[1]中国农业大学农学院,农业生物技术国家重点实验室,杂种优势研究与利用教育部重点实验室,作物遗传改良北京市重点实验室,北京100193

出　　处：《科学通报》2022年第26期3207-3220,共14页Chinese Science Bulletin

基　　金：国家重点基础研究发展计划(2007CB109001);“科技兴蒙”行动重点专项(NMKJXM202111)资助。

摘　　要：北方冬麦区骨干亲本农大3338与京冬6号组配的杂交F1代,在株高和千粒重等方面表现较强的中亲杂种优势.为解析该组合杂种优势形成的遗传基础,利用农大3338和京冬6号构建了双单倍体(doubled haploid,DH)群体,并利用DH群体衍生了一套包含283个杂交组合的小麦永久F_(2)群体,在两个不同环境下进行杂种优势评价.利用包含单核苷酸多态性(single nucleotide polymorphism,SNP)和简单重复序列(simple sequence repeat,SSR)分子标记的高密度整合遗传连锁图谱,基于完备区间作图法,对永久F_(2)群体在两个环境下的株高、千粒重、中亲优势值和相应的BLUP值进行全基因组数量性状基因座(quantitative trait locus,QTL)定位和上位性互作分析.共检测到32个株高QTL和25个千粒重QTL,分别解释0.54%~36.05%和0.87%~25.78%的表型变异,包含加性效应、显性效应和超显性效应位点,其中2D、4B、4D和6A染色体上存在稳定主效QTL,主要以加性效应为主.利用中亲优势值分别检测到13个株高杂种优势QTL和15个千粒重杂种优势QTL,绝大部分QTL表现为超显性效应.株高和千粒重上位性互作分析结果表明,在加加互作、加显互作、显加互作和显显互作4种不同互作类型中,显显互作的效应值最大,且所占比例最高.因此,本研究结果表明,超显性、显性和上位性是该组合杂种优势遗传基础的重要组成部分,为3种遗传效应共同调控杂种优势形成提供了有力的证据,对杂交小麦亲本创制和强优势组合选配具有重要意义.Heterosis refers to the phenomenon that a heterozygous hybrid exhibits superior performances over its parents,which has been suggested as a solution to overcome yield stagnation of wheat.However,the molecular basis of wheat heterosis is still poorly understood.We have previously found that a cross derived from the winter common wheat Nongda3338(ND3338)and Jingdong 6(JD6)showed strong mid-parent heteroses on plant height(PH)and thousand grain weight(TGW).In this study,we further aimed to investigate the genetic underpinnings of PH and TGW using an“immortalized F_(2)”(IF_(2))derived from the ND3338/JD6 doubled haploid(DH)population.The PH and TGW of DH and IF_(2) populations were evaluated across two different environments,and the mid-parent heterosis value(HV)was used to measure heterosis.The direction and magnitude of HV greatly varied between PH and TGW across the environments.A two-way analysis of variance(ANOVA)was performed for PH and TGW in the IF_(2) population,revealing that genetic variation was the main source,despite the significant variations found from the environments and genotype by environment interaction.The broad sense heritability of PH and TGW in IF_(2) population was 94.05%and 88.14%,respectively.Pearson’s correlation coefficients of PH,TGW,HV_(PH) and HV_(TGW) in the IF_(2) population were estimated based on the best linear unbiased prediction(BLUP)values of two environments,showing that PH was significantly positively correlated with TGW and HV_(TGW),TGW was significantly positively correlated with HV_(TGW) and negatively correlated with HV_(PH),while HV_(PH) had a strong positive correlation with HV_(TGW).The genotypes of the IF_(2) population were deduced from corresponding DH parents.Based on the inclusive composite interval mapping method,quantitative trait locus(QTL)mapping was separately conducted with PH,TGW,HV_(PH) and HV_(TGW) using the QTL IciMapping software.We identified a total of 32 and 25 QTL that exhibited additive,dominant and overdominant pattern associated with PH an

关 键 词：小麦 杂种优势 永久F2群体 数量性状位点 株高 千粒重 

分 类 号：S512.1[农业科学—作物学]