花生出仁率和株高的QTL定位分析

QTL Mapping for Shelling Percentage and Plant Height in Cultivated Peanut(Arachis hypogaea L.)

花生出仁率、株高等性状都对产量有重要影响,鉴定出仁率和株高相关的主效QTL,分析QTL的加性、上位性及其与环境的互作效应以及出仁率与株高之间的遗传关系,有助于加快花生分子育种研究进程。本研究以远杂9102×徐州68-4构建的RIL群体为材料,在4个环境中调查出仁率和株高等表型性状,相关性分析结果表明,4个环境中,出仁率与株高均存在极显著负相关。利用前期构建的高密度遗传图谱,通过QTLNetwork 2.0软件对出仁率和株高进行QTL定位分析,检测到13个具加性效应的出仁率QTL,8个具加性效应的株高QTL,其中,2个与出仁率相关的主效QTL(qSPA05.2和qSPA09.1)和1个与株高相关的主效QTL(qPHA09.1)至少能在3个环境下被重复检测到。还检测到11对上位性QTL,包括出仁率6对和株高5对,与环境之间均存在互作效应。比较QTL在连锁群上的位置发现,在A09染色体Ad91I24–AGGS2492区间同时检测到稳定的出仁率主效QTL(qSPA09.1)和株高主效QTL(qPHA09.1)。通过条件QTL排除该位点株高的效应后,出仁率加性效应贡献率从14.37%下降到5.50%,表明qSPA09.1和qPHA09.1为同一位点,同时控制株高和出仁率。

Peanut yield is greatly influenced by shelling percentage （SP） and plant height （PH）. Marker-assisted selection for shelling percentage and plant height improvement can be facilitated by detecting additive and epistatic QTLs, understanding their interactions with environment, as well as the genetic relationship between SP and PH. In a four-year experiment, the variations of SP and PH were evaluated with the recombinant inbred line population derived from the cross between Yuanza 9102 and Xuzhou 68-4. QTLs associated with SP and PH were analyzed using a high density linkage map and QTLNetwork 2.0 software. The re-sults showed that SP and PH were negatively correlated （P 〈 0.01）. Thirteen and eight additive QTLs were identified for SP and PH, respectively. Major loci qSPA05.2 and qSPA09.1 for SP and major locus qPHA09.1 for PH were repeatedly detected in three or four years. Six pairs of epistatic QTLs for SP and five pairs of epistatic QTLs for PH were identified, and they all had interac-tion effects with environment. qSPA09.1 and qPHA09.1 were located in the same interval （Ad91I24–AGGS2492） on chromosome A09. The additive effect of this locus for SP variation decreased from 14.37% to 5.50% after eliminating the PH effect, suggesting the pleiotropism of qSPA09.1 for SP and qPHA09.1 for PH.