寒温带水曲柳自然群体变异分析及 优良个体的早期选择与评价

以寒温带水曲柳(Fraxinus mandshurica Rupr.)自然群体及子代测定林为对象,采用固定标准地定位观测的方法,以群体选择、变异分析和遗传效应评价为基础,探讨自然群体及其子代树高和胸径性状的遗传变异,系统分析这些生长性状的遗传力和遗传增益,从中选择出生长势、抗逆性和适应能力兼优的优异群体及优良个体.结果表明:寒温带水曲柳自然群体间的生长性状存在极显著差异,其中,树高性状的变异较小,胸径性状的变异较大,平均变异系数分别为24.29%和45.02%.另外,群体内自由授粉子代间生长性状的差异亦极显著.寒温带水曲柳的生长性状受遗传基因的控制程度较强,遗传力强,遗传增益较大,树高和胸径的遗传力分别为0.858和0.860,遗传增益分别为16.68%和30.98%.因此,以生长性状为主要评价指标,兼顾各种影响因素,确定五常(WCH)群体为优异群体,WCH25,WCH12和WCH27为优良个体,可广泛应用于多世代遗传改良育种中.

Analysis on the Natural Populations Variation,Early Selection and Evaluation of the Excellent Individual of Fraxinus mandshurica in the Cool Temperature Zone

By the method of positional observation of fixed standard fields,this thesis performed on discussing the genetic variation of the tree height and DBH from the natural populations and open-pollinated progenies, and analyzing systematically the heritability and the genetic gains in quantity characters on the basis of analyzing and evaluating its selection of population,the genetic variation and the heredity effects,then screened out excellent ones and its individual both growth vigor,resistance and adaptability from these populations. The research results showed that there were greatly significant difference on the quantitative characters among the natural populations of Fraxinus mandshurica in the Cool Temperature Zone, and the coefficient of variance from the tree height (24. 29%) was smaller,but its DBH (45. 02%) was larger. On the other hand,there was greatly significant difference among its open-pollinated progenies on the tree height and DBH within natural populations. Meanwhile,the growth characters had strong heritability,high genetic gain,and remarkable heredity effects. The heritability of tree height and its DBH was 0. 858 and 0. 860,and the genetic gain were 16. 68% and 30. 98%, respectively. Therefore,WCH was determined to be excellent natural population both in the growth,resistance and adaptation with growth traits as the main evaluation index,and WCH25,WCH12 and WCH27 were determined to be excellent individuals, which were applied in the advanced generation improvement breeding. All these for utilizing legitimately the genetic resource distributed in the Cool Temperature Zone, and for improving the scientific additional value of superior populations from Fraxinus mandshurica.