马尾松纸浆材重要经济性状配合力及杂种优势分析

报道了马尾松不同种源优良无性系 6× 6全双列交配的 7a生遗传测定林的分析结果。研究发现 ,树高、胸径和材积生长、干物质积累及木材基本密度等纸浆材主要经济性状的一般配合力 (GCA)和特殊配合力 (SCA)效应极为显著 ,但显性基因效应起主导地位 ,加性基因效应次之。基因上位效应则因性状而异 ,仅对木材基本密度作用显著 ,而对树高、胸径、材积生长和干物质积累作用较小或可忽略。马尾松生长和材质材性指标的遗传控制模式不同于玉米、杉木等研究结果 ,这可能与交配亲本来源于不同地理种源及经过一般配合力间接选择有关。马尾松生长性状普遍存在自交衰退现象 ,一般配合力小的亲本自交衰退程度有增加的倾向。马尾松不同交配组合间的杂种优势差异巨大 ,正反交杂种优势在总体上大致相似。研究虽然发现一般配合力较高的亲本间杂交在材积增加和干物质积累等性状上会产生强杂种优势的倾向 ,却无明显的规律可寻。以干物质指数作为主要筛选指标 ,初选出 8个优良杂交组合

Analysis on Combining Ability and Heterosis of Main Economic Traits of Pinus massoniana for Pulp Production

This paper gave the results at age 7 from a complete-diallel cross among 6 Pinus massoniana clones from different seed sources. It was found that variances due to general combining ability (GCA) and specific combining ability (SCA) were significant for height, DBH, volume index, wood basic density and dry matter index. However, the dominant gene effect was predominant over the additive effect. Epistasis effect was varied with traits tested. Analysis of data revealed marked epistasis gene action for wood basic density. Inheritance pattern of growth and wood properties was found to be different from maize and Chinese Fir. The main reason for this seemed to be that the mating parents were from different seed sources and/or indirect selection on GCA of growth had been made for mating parents. There was usually selfing depression for growth traits. Selfing progeny from parents with smaller GCA seemed to reveal more significant depression. Heterosis between various cross combinations was greatly varied. As a whole, reciprocal crosses had similar heterosis. There were some but no obvious trend that the cross between parents with larger GCA could produce more heterosis in volume increment and dry matter accumulation. Eight superior cross combinations for pulp wood were screened based on dry matter index.