植物学报2025，Vol.60Issue(3)：342-353,12.DOI:10.11983/CBB24047
基于高密度Bin图谱的水稻苗期耐热性QTL定位
Mapping of QTLs for Heat Tolerance at the Seedling Stage in Rice Based on a High-density Bin Map
摘要
Abstract
INTRODUCTION:As the main grain crop,rice plays an important role in ensuring food security of China.Rise in global average temperature is detrimental to crop yield and heat stress is currently one of the major abiotic threats on rice production.There are significant variations in heat tolerance among different rice varieties.As a typical quantitative trait,heat tolerance of rice is controlled by multiple genes.Identification of new QTLs and genes related to heat tolerance is very important for the genetic research and the breeding of new heat-tolerant rice varieties. RATIONALE:In recent years,many heat tolerant QTLs had been identified with different genetic populations and evaluation indicators at different growth stages.Most of those QTLs were mapped in large intervals due to the limited population sizes,simplified experimental designs and inaccurately controlled environments.The heat tolerance level identification in a population is very difficult for mature plants.Therefore,we developed a population of recombinant inbred lines(RILs)with 186 lines derived from japonica rice TD70 and indica rice Kasalath,which showed large varia-tions in seedling survival rates under high temperature stress(HTSR).QTLs associated with HTSR were mapped by the high-density linkage Bin-map and candidate genes were identified. RESULTS:Twenty-six QTLs related to the HTSR were mapped on 11 of the 12 chromosomes,with the exception of 3.The LOD values of single QTL ranged from 2.59-16.15,four of which with LOD values greater than 10.Seven QTLs were located within the same interval or adjacent to known heat tolerance QTLs.The major locus of qHTSR5.2 was located in the 26.25-26.38 Mb region of Chr.5 with an LOD value of 12.07,which explained 7.18％of the total pheno-typic variation in the HTSR.According to the annotation and sequence analysis of the genes located in the region of four major QTLs,we found that twenty-seven annotated genes with non-synonymous mutations in the coding regions be-tween TD70 and Kasalath.Five of them were identified as potential candidate genes because the RILs sharing each of the distinct haplotypes of their parents for each gene exhibited significant different HTSR resistance level.Among them,three candidate genes encode heat shock proteins HSP20 or HSP17.5. CONCLUSION:We detected 26 QTLs controlling seedling heat tolerance based on a high-density Bin map in a RIL population.Some of the QTLs were overlapped with known heat tolerance loci,indicating their strong effects on regu-lating heat tolerance of rice.Five candidate genes were identified through gene annotation,parental sequence com-parison,effect analysis of heat tolerance between RILs with different haplotypes.The candidate genes identified in our study could be used for molecular mechanism research on high temperature tolerance of rice in the future.关键词
耐热性/高密度Bin图谱/QTL定位/水稻/苗期Key words
heat tolerance/high-density Bin map/QTL mapping/rice/seedling stage引用本文复制引用
赵凌,管菊,梁文化,张勇,路凯,赵春芳,李余生,张亚东..基于高密度Bin图谱的水稻苗期耐热性QTL定位[J].植物学报,2025,60(3):342-353,12.基金项目
江苏省种业振兴"揭榜挂帅"项目(No.JBGS(2021)040) （No.JBGS(2021）
