基于QTL定位的蓖麻株高性状遗传解析

Genetic Analysis of Traits Related to Plant Height in Ricinus communis L.Based on QTL Mapping

用YC2(高杆)×YF1(矮杆)和YC1(高杆)×YF1(矮杆)组合衍生的2个F2代群体,对蓖麻株高性状进行相关、回归和QTL定位分析。结果表明,株高与主穗位高、主茎节长和主茎茎粗之间显著正相关,但与主茎节数不相关;主穗位高与主茎节数、主茎节长和主茎茎粗之间呈显著正相关;主茎节数与主茎节长之间呈显著负相关。利用QTLNetwork 2.0软件在YC2×YF1的F2群体中检测到株高、主穗位高、主茎节数、主茎节长和主茎茎粗的5、4、6、3和2个QTL,分别解释了45.9%、45.3%、66.1%、55.4%和12.6%的总变异。在YC1×YF1的F2群体中检测到3、4、5、1和2个上述5性状的QTL,分别解释了26.0%、25.5%、35.4%、37.4%和7.6%的总变异。证明QTL间的"一因多效"和连锁是株高、主穗位高和主茎节长之间高度相关的遗传基础,加性效应是株高、主穗位高和主茎节长的主要遗传组分,互作效应是主茎节数和主茎茎粗的主要遗传组分。建议育种上将主穗位高和主茎节长作为株高早期选择和预测的间接指标,并将多节数和短节间作为高产育种的主攻方向。

The traits related to plant height were analyzed with correlation, regression and QTL mapping in two F2 populations derived from crosses of YC2×YF 1 and YC 1 ×YF 1, respectively. The results indicated that plant height （PH） was significantly and positively correlated with bearing height of primary raceme （PRH）, length of main stem internode （MSIL） and main stem diame- ter （MSD） but not with node number of main stem （MSNN）, PRH was significantly and positively correlated with MSNN, MSIL and MSD, MSNN and MSIL was significantly and negatively correlated with each other. In F2 population from a cross of YC2×YF1, five, four, six, three, and two QTLs for PH, PRH, MSNN, MSIL, and MSD were detected by QTLnetwork 2.0, which explained for 45.9%, 45.3%, 66.1%, 55.4%, and 12.6% of the phenotypic variation, respectively. In F2 population from a cross of YC1×YF1, three, four, five, one, and two QTLs for the five traits mentioned above were detected, which explained for 45.9%, 45.3%, 66.1%, 55.4%, and 12.6% of the phenotypie variation, respectively. We concluded that the pleiotropy or linkage between QTLs results in the positive correlation between PH, PRH and MSIL, the additive effect was the main genetic component of PH, PRH, MSIL, and the epistatic effect is the main genetic component of MSNN and MSD. It suggested that PRH and MSIL should be used to select and predict PH indirectly in the early stage, more MSNN and shorter MSIL should be regarded as the target traits for high-yield breeding.