白桦种群间木材纤维性状的表型变异与分子标记的遗传多态性

以东北地区的5个白桦天然种群为研究材料,在木材纤维形态性状测定的基础上,采用ISSR、RAPD分子标记研究了5个种群的遗传变异以及种群间纤维形态性状与DNA分子标记的相关性.结果表明:白桦天然林成熟材(18～31年生)的木材纤维长度在种群间差异不显著,纤维宽度和长宽比差异显著,帽儿山种群的木材纤维形态性状最好,汪清最差;利用ISSR和RAPD 2种标记检测5个白桦种群的遗传多样性,所得的研究结果基本一致,多态位点比率最高的为辽宁新宾种群,其次是帽儿山和汪清,而塔河和金山屯最低;ISSR标记的AMOVA分析表明白桦种群间的遗传变异占总遗传变异的10.82%;RAPD标记的AMOVA分析表明白桦种群间的遗传变异占总遗传变异的12.94%,研究结果均显示白桦的遗传变异主要发生在种群内部.利用2种标记技术的种群聚类结果基本一致,这一结果与基于木材纤维性状的表型聚类基本一致, 而且种群间遗传距离和地理距离之间存在一定的相关性.

Phenotypic Variation in Wood Fiber Properties And Genetic Diversity in Molecular Marker among the Populations of Betula platyphylla

Five natural populations of Betula platyphylla from northeast part of China were taken as the materials, of which ISSR and RAPD molecular markers were used to detect the genetic diversity, and then the correlation between the fiber properties and DNA markers among the populations was studied based on the fiber property measuration. The result indicated that there was no significant difference among five mature stands in fiber length of the wood, but significant differences in fiber width and the ratio of fiber length to width. The fiber properties of Maoershan population were the best and Wangqing population the worst. The similar trend existed in genetic diversity among five populations detected by beth molecular markers, which displayed the highest value in polymorphic loci percentage for Xinbin population, the second for Maoershan and Wangqing populations, the lowest for Tahe and Jinshantun. By AMOVA analysis, 10.82% of total genetic variation existed among the populations in ISSR markers and 12.94% of that in RAPD marker. That meant the genetic variation of B. platyphylla mainly occurred within the populations. The cluster analysis result according to the genetic distance among five populations by both markers was similar to that according to the fiber properties. Also, some correlation was showed between genetic distance by marker detection and geographic distance among the populations.