马尾松双列杂交亲本遗传距离与杂种生长优势相关性分析

马尾松6×6全双列杂交的不同组合,其11年生子代在生长性状及其杂种优势上均存在较大的差异。对亲本遗传距离与子代杂种优势的相关分析发现:亲本的ISSR遗传距离(0.266 0~0.467 0)与子代树高、胸径等生长性状及其杂种优势表现为显著的线性正相关,遗传距离与正、反交子代材积杂种优势的相关系数分别达到0.601和0.597,表明随着亲本间遗传距离的增大,子代各生长性状的杂种优势将呈线性增加。马尾松亲本遗传距离与子代杂种优势的相关性明显高于遗传距离与子代生长性状的相关性,表明根据亲本遗传距离对子代杂种优势进行预测比直接预测子代生长性状更可靠。根据这一结论,优先选择树高、材积等经济性状优良同时遗传距离较大的杂交亲本,有望提高子代杂种优势幅度并获得材积性状优良的子代。

Genetic distances of parents of Pinus massoniana and relationship between growth traits and heterosis of progeny

Large degree of variation in growth performance and heterosis were found among different cross combinations of 6×6 diallel cross of Pinus massoniana. ISSR(intro-simple sequence repeat) was employed to detect the relationship between the parental GD (genetic distance) and hybrid performance. Significant positive correlation between parental GD and hybrid performance was found, and the correlation coefficient between GD and heterosis of volume index was 0.601 and 0.597 for forward and reverse hybridizations respectively. It was also demonstrated that the correlation between GD and heterosis was larger than that between GD and progeny growth performance, which indicated that it would be more effective to predicting heterosis than predicting growth traits. Based on this conclusion, to produce progeny with both large heterosis and excellent growth performance, the genotypes with superior growth performance and large genetic distance should be preferred in the selection of parents.