杉木种源地理变异的影响因子及性状遗传、相关和选择

GEOGRAPHIC VARIATION AND INHERITANCE, CORRELATION AND SELECTION OF TRAITS OF PROVENANCES OF CHINESE FIR

研究表明,影响种源生长的主要因素是温度、湿度和日照时数,而导致木材比重自东向西递减的主要原因可能是日照时数和降水量。种源表型的优劣与其对气候的适应性无关。在种源水平上,杉木各性状具有中等或较强的遗传力,其中以生长性状为最高。3个生长性状(H_8、D_8、H_2)之间、两个分枝性状(NB、NW)之间,以及冠幅(CD)与胸径(D_8)之间,都存在着很强的表型和遗传相关性,而木材比重(SG)与其它性状之间的相关都非常微弱。利用Smith-Hazel指数对种源进行选择,可以使木材比重保持平均水平,而使生长和形态(尤其是8年生胸径和树高)性状的遗传进度达到最大。选出的10个最优种源为:湖南会同、广西融水、湖南祁阳、广东乐昌、广西那坡、福建永春碧卿、湖南江华、贵州锦屏、福建永安大湖和广东信宜。

This study reveals that the leading climatic factors which result in variation of growth are temperature, humidity and hours of sun. But for specific gravity, the main reason for decreasing from east to west seems to be hours of sun and precipitaion. There is no evidence that the traits of provenance are related to its adaptation to climate. There are medium or stronger degrees of genetic control for all traits measured on the provenance level (0. 43-0.75). Highly phenotypic and genetic correlations were found among three growth tratis and among two branch traits and between crown and diameter. Specific gravity is apparetly inherited independently. By using Smith-Hazel index selection, it is pussible to maximize genetic gains of growth and branch traits (especially for DBH and H at 8-year-old) while holding genetic gains of specific gravity to zero. Ten super provenances were selected.