摘要： 在盐、碱胁迫条件下，分析水稻苗期的根数和根长并定位其QTL位点，为水稻的耐盐性和耐碱性的遗传机制及分子标记辅助育种提供理论基础。以盐碱敏感水稻品种东农425与强耐盐碱水稻品种长白10为亲本构建的重组自交系（RIL）为作图群体，在盐胁迫140 mmol/L的NaCl和碱胁迫0.15% Na₂CO₃的处理条件下，以正常浇灌为对照，进行水稻苗期时根数和根长的测定，利用QTL IciMapping v3.3软件的完备区间作图法（ICIM）分别对盐、碱胁迫和对照条件下水稻的根数和根长进行QTL分析。检测到18个加性效应QTL，在第1，2，3，4，5，7，8，9和10染色体上，LOD值为2.01~3.35，表型变异的贡献率为6.02%~20.06%。自然条件下，检测到4个与根数相关的QTL，qNRN7-2贡献率最大，为12.46%，未检测到根长相关的QTL。在盐胁迫下，共检测到5个与根长、根数相关的QTL，qSRN3的贡献率最大，为20.06%。在碱胁迫下，共检测到与根数和根长相关的3个QTL，qARN2的贡献率为12.99%；qARL3和qARL5的贡献率分别为7.04%和8.88%。共检测到4个自然条件与盐胁迫差值的根数和根长相关的QTL，其中，qN-SRN8-2和qN-SRL1贡献率较大，分别为14.01%和14.12%。在自然条件与碱胁迫的差值条件下，共检测到2个与根长、根数相关的QTL，分布在3，10号染色体上；检测到1个与根数相关的QTL，位于3号染色体上的qN-ARN3，贡献率为6.02%；检测到1个与根长相关的QTL，位于10号染色体上的qN-ARL10，贡献率为7.45%。在盐胁迫和碱胁迫条件下，水稻苗期的根数和根长都受到明显影响，相对于盐胁迫，水稻对碱胁迫更为敏感。

关键词: 水稻, 盐胁迫, 碱胁迫, 根数, 根长, QTL

Abstract: The number and the length of roots as well as its QTL would provide theoretical basis for genetic mechanisms and molecular marker assisted breeding of salt and alkaline tolerance. Recombinant inbred lines(RIL)of sensitive varieties Dongnong 425 tolerant varieties Changbai 10 cross were treated with 140 mmol/L NaCl and 0.15% Na₂CO₃ as salt and alkali stress,and normal condition as control. The number and the length of roots during seedling stage were measured,and using complete interval mapping(ICIM)of QTL IciMapping v3.3 software to analysis the QTL under salt,alkali and normal conditions. We detected eighteen additive QTL located on 1,2,3,4,5,7,8,9 and 10 chromosomes with LOD 2.01-3.35,and the contribution rate to phenotypic variation was 6.02%-20.06%.Under natural conditions,four QTL related to the root number were detected,among which,12.46% was the largest contribution rate of qNRN7-2,while no QTL were detected related to the root length. Under salt stress,five QTL were detected related to the number and length of roots,among which,20.06% was the largest contribution rate of qSRN3. Under alkali stress,three QTL related to the root number and root length were detected. The contribution rate of qARN2 was 12.99%,and the contributions of qARL3 and qARL5 were 7.04% and 8.88% respectively. We found four different number and length related QTL between normal and salt condition. Among them,the contribution rates of qN-SRN8-2 and qN-SRL1 were relatively large,14.01% and 14.12%,respectively.In normal and alkali conditions,two number and length related QTL were detected on 3 and 10 chromosomes. One QTL associated with root number, qN-ARN3,located on chromosome 3,with contribution rate 6.02%.One QTL were detected related to the number and length of roots,among which,7.45% was the largest contribution rate of qN-ARL10 on chromosome 10. Under alkali and salt stress conditions,the number and length of rice seedling roots were significantly affected,and compared with salt stress,rice was more sensitive to alkali stress.

Key words: Rice, Salt stress, Alkali stress, Root number, Root length, QTL

中图分类号: 

• S511.03