基于三维模型重构的花生网纹厚度性状QTL分析

QTLs analysis for reticulation thickness based on reconstruction of three dimensional models in peanut pods

荚果网纹厚度,不仅是花生重要的品种特性,也与花生适宜机械化收获特性密切相关。为探索花生荚果网纹厚度遗传基础,本研究开发了一种基于三维模型重构测定网纹厚度的方法,并且以品种花育36号和品系6-13配组衍生的181个重组自交系(recombinant inbred line,RIL)群体为材料,考察了该RIL群体2019—2020年在山东青岛、东营和威海3个环境下表型数据。结果表明,横向和纵向网纹厚度在RIL群体中均表现为连续分布和超亲遗传,广义遗传率分别为0.92和0.91。利用前期构建的高密度遗传图谱,共定位到11个与网纹厚度相关加性QTL,其中6个与横纹厚度相关,5个与纵纹厚度相关,表型贡献率范围为5.21%~11.06%。定位到2个主效位点qLA2和qLO9,可在不同环境下表达,其增效等位基因分别来自花育36号和6-13。共定位到22对上位性QTL,共涉及34个位点,表型贡献率范围为0.55%~4.37%,其中10对与横纹厚度相关,12对与纵纹厚度相关。本研究结果将为花生相关性状基因定位和分子育种提供重要的参考。

The thickness of pod reticulation is not only an important criterion of peanut taxonomy,but also an agronomy trait related to peanut mechanical harvesting.To explore the genetic mechanism of reticulation thickness of peanut pods,a novel phenotyping method was developed to determine the reticulation thickness through reconstructing three dimensional(3D)models of pods.Meanwhile,a recombinant inbred line(RIL)population(181 lines)was derived from a cross between Huayu 36 and 6-13and planted in three environments from 2019 to 2020,including Qingdao,Dongying,and Weihai of Shandong province.Phenotypic data of the RIL population were collected from these three environments.Two related traits,thicknesses of latitudinal and longitudinal protuberant veins(reticulations),had continuous and transgressive distributions in the RIL population,with broad-sense heritablities of 0.92 and 0.91,respectively.Based on a previous high density genetic map,a total of 11 additive QTLs were identified explaining phenotypic variations of 5.21%–11.06%,among which six QTLs were related to thickness of latitudinal protuberant vein and five related to thickness of longitudinal protuberant vein.Two major loci,qLA2 and q LO9 could be detected in more than one environments,with contributing alleles coming from Huayu 36 and 6-13,respectively.A total of 22 pairs of epistatic QTLs involving 34 loci were identified explaining phenotypic variations of 0.55%–4.37%,among which 10 pairs of interactions were related to thickness of latitudinal protuberant vein and 12 pairs were related to thickness of longitudinal protuberant vein.These results provide valuable information for further gene mapping and molecular breeding in peanut.