枇杷果、叶、花相关性状QTL定位分析

Quantitative Trait Locus Mapping and Analysis of Traits Related to Flower,Fruit,and Leaf in Loquat

以枇杷‘宁海白’ב大房’的130株F1群体为研究对象,利用已构建好的枇杷高密度遗传图谱,对枇杷17个果、叶、花相关性状进行QTL定位以及对关键QTL区间进行候选基因筛选。17个性状共获得153个QTL,其中果横径、果肉厚、种子数、种子质量、果形指数、花序宽、叶片长、叶片宽和叶基形状9个性状定位的QTL贡献率均在25%以上。特别是第4连锁群(LG4:13.500~14.276 cM和23.646~24.804 cM)、第8连锁群(LG8:0~8.851 cM)、第12连锁群(LG12:41.198~45.852 cM和65.246~66.407 cM)以及第15连锁群(LG15:92.921~95.244 cM)这6个区间有6个以上性状的QTL重合,且多个性状的QTL贡献率在35%以上。在第12连锁群(LG12:41.198~45.852cM)和第15连锁群(LG15:92.921~95.244 cM)重合区间挖掘到13个与植物生长发育、细胞分裂、细胞膨大以及植物激素调控相关的候选基因。

The study focused on an F1 population of 130 individuals from the cross between‘Ninghaibai’בOobusa’loquat cultivars.Based on a well-constructed high-density genetic map of loquat,QTL mapping was performed for 17 fruit-,leaf-and floral-related traits,and candidate genes were screened from the key QTL intervals.The results showed significant correlations exceeding the significance level among multiple traits.A total of 153 QTLs were identified for the 17 traits.Nine traits,including transverse diameter,flesh thickness,seed number,seed weight,fruit shape index,width of leaf blade,length of leaf blade,width of leaf blade,and shape of leaf base,had QTLs with phenotypic variance explained rates of above 25%.Notably,six QTL intervals on LG4(13.500–14.276 cM and 23.646–24.804 cM),LG8(0–8.851 cM),LG12(41.198–45.852 cM and 65.246–66.407 cM),and LG15(92.921–95.244 cM),were shared among six or more traits,with phenotypic variance explained rates above 35%for multiple traits.Furthermore,a total of 13 candidate genes related to plant growth and development,cell division,cell expansion,and plant hormone regulation were obtained from the overlapping intervals of LG12(41.198–45.852 cM)and LG15(92.921–95.244 cM).