野生二粒小麦粒重相关基因GW2的克隆及其单倍型分析  

Cloning and Haplotype Analysis of Grain Weight Related Gene GW2 in Wild Emmer Wheat

作　　者：王利 魏新雨 杨文琪 贾彦哲 李冰冰 吕树作 聂小军[2] WANG Li;WEI Xinyu;YANG Wenqi;JIA Yanzhe;LI Bingbing;LÜShuzuo;NIE Xiaojun(Institute of Agricultural Resources and Environmental Science,Shandong Academy of Agricultural Sciences,Jinan,Shandong 250100,China;College of Agriculture,Northwest A&F University,Yangling,Shaanxi 712100,China;Luoyang Academy of Agricultural and Forestry Sciences,Luoyang,Henan 471027,China)

机构地区：[1]山东省农业科学院农业资源与环境研究所,山东济南250100 [2]西北农林科技大学农学院,陕西杨凌712100 [3]洛阳农林科学院,河南洛阳471027

出　　处：《麦类作物学报》2024年第8期966-974,共9页Journal of Triticeae Crops

基　　金：国家重点研发计划项目(2021YFD1900190)。

摘　　要：野生二粒小麦作为普通小麦A、B基因组供体,具有遗传类型多、变异丰富,以及粒重、粒大、抗病、耐逆等优良特性,一直是小麦遗传改良重要的种质资源和基因库。GW2(grain width 2)基因是调控水稻、小麦等谷类作物籽粒重量和宽度的关键基因,对高产育种具有重要价值。为了明确野生二粒小麦GW2基因的遗传变异,挖掘其优异单倍型,本研究克隆了野生二粒小麦的GW2基因并进行了序列特征和基因结构等分析。结果显示,在野生二粒小麦中,GW2基因具有A和B两个同源拷贝,分别命名为TdGW2-A和TdGW2-B,两者均编码一个425 aa的蛋白序列,并具有一个Ring结构域。基于公共数据库的重测序数据分析发现,野生二粒小麦、栽培二粒小麦和硬粒小麦的GW2-A/GW2-B的π值分别为0.297239/0.332527、0.295072/0.296317和0.264839/0.198636,推测两个同源拷贝在四倍体小麦驯化过程中均发生了遗传瓶颈效应,其B拷贝受到的瓶颈效应更强。单倍型分析发现,TdGW2-A和TdGW2-B分别具有4种单倍型;栽培二粒小麦和硬粒小麦A拷贝具有5种单倍型,B拷贝只有3种单倍型;3种四倍体小麦的GW2-A和GW2-B主要单倍型占比分别为58%/63%、65%/83%和77%/67%,暗示驯化和人工选择趋向于主要单倍型。本研究克隆了野生二粒小麦粒重基因GW2并初步分析了其在四倍体小麦中的遗传分化和单倍型,为进一步挖掘野生二粒小麦粒重优异单倍型和功能性分子标记开发奠定了基础。Wild emmer wheat(Triticum dicoccoides)is the donor of the A and B subgenome of bread wheat,with various excellent characteristics,such as multiple genetic types,high genetic variations,high grain weight as well as outstanding disease resistance and stress tolerance,and thus it is always considered as an important germplasm resource and gene bank for wheat genetic improvement.Previous studies have found that GW2 is a key gene regulating grain weight and width in cereal crops,such as rice and wheat,having important value for crop high-yield breeding.In order to clarify the genetic variation of the GW2 gene in wild emmer wheat and explore its excellent haplotypes,this study firstly cloned the full-length GW2 from wild emmer wheat,which has two homologous A and B copies,namely TdGW2-A and TdGW2-B.Both of them encode a protein with 425 amino acids with a Ring domain.Furthermore,based on the re-sequencing data from public databases,theπvalues of GW2-A and GW2-B in wild emmer wheat,cultivated emmer wheat,and durum wheat were 0.297239/0.332527,0.295072/0.296317 and 0.264839/0.198636,respectively,indicating an obvious genetic bottleneck effect during the domestication process of tetraploid wheat.Finally,haplotype analysis revealed that wild emmer wheat had four haplotypes for TdGW2-A and TdGW2-B respectively,while that of cultivated emmer wheat and durum wheat had five haplotypes in TdGW2-A,and only three haplotypes in TdGW2-B.The main haplotypes of GW2-A and GW2-B in these three emmer wheat populations were 58%/63%,65%/83%,and 77%/67%,respectively,suggesting a trend towards selecting the main haplotypes in domestication and genetic improvement processes.This study conducted a preliminary analysis of the genetic differentiation and haplotypes composition of GW2 in tetraploid emmer wheat,providing useful information for further exploring the excellent haplotypes of grain weight in emmer wheat and laying the foundation for the development of functional molecular markers.

关 键 词：野生二粒小麦 GW2 单倍型 遗传多样性 

分 类 号：S512.9[农业科学—作物学] S330