利用基础导入系群体定位氮胁迫下水稻产量性状QTL

摘要

The genetic mechanism underlying yield traits is very complex, while QTL of rice yield traits which are uncovered in nitrogen starvation condition can provide a valuable reference to explain the genetic mechanism of yield traits, and facilitate fine QTL mapping and gene cloning, as well as screening of selective breeding of rice varieties tolerant to nitrogen starvation. In this study, 66 ILS population derived from the cross of Shuhui 527 (Oryza. sativa ssp. indica) and Chujing 12 (0. saliva ssp.japonica) which were served as the recurrent parent and donor parent; both marker-assisted selecting and high-generation backcrossing were used to detect QTL under the field experiment with normal and nitrogen starvation conditions by mapping with the single marker. A total of 24 QTLs were detected. Among of these QTLs, 20 QTLs were newly characterized, while qpn-1, qph-1, qby-A and qby-2 were similar to the previous studies, qph-la and qph-lb could affect the height of the site under the different treatments; we also found that both in the QTL of panicle number and grain yield per plant were linked with marker RM521 under nitrogen starvation condition; the additive effects of qpn-lb, qpn-2a and qpn-2b were less than 1. The results show that nitrogen starvation has strong negative effect on grain yield, panicle number, and biomass yield. Introgression lines population has strong ability for detecting micro effect QTL.%水稻产量性状的遗传机制复杂,在低氮胁迫下进行QTL定位,可为产量性状遗传机制的解释、基因的精细定位和克隆提供参考价值,也可为筛选耐低氮水稻材料提供有价值的参考.本研究以66个水稻籼粳交片段导入系群体[粳稻(Oryza sativa ssp,japonica)楚粳12是供体亲本,籼稻(O.sativa ssp,indica)蜀恢527是受体亲本,采用回交和分子标记辅助选择相结合的方法构建]为定位群体,利用单标记作图法,对正常与低氮胁迫条件下水稻有效穗、单株产量、株高和生物学产量等性状进行QTL定位.共检测到24个QTLs,20个为新检测出的QTL,而qph-1、qpn-1、qby-2、qby-4与前人研究结果相似,另外,qph-1a和qph-1b为在不同处理下均能影响株高的位点；生物学产量的QTL仅在低氮处理下被检测到；qpn-2b与qyd-2具有共同的连锁标记RM521；qpn-1b、qpn-2a、qpn-2b等加性效应值都小于1.结果表明,低氮胁迫明显影响单株有效穗、单株产量和生物学产量,且导入系群体检测微效QTL的能力较强.