植物生态学报 ›› 2006, Vol. 30 ›› Issue (1): 165-173.DOI: 10.17521/cjpe.2006.0023

• 研究论文 • 上一篇    下一篇

云杉天然群体遗传多样性的等位酶变异

罗建勋1, 顾万春2,*(), 陈少瑜3   

  1. 1 四川省林业科学研究院林业研究所,成都 610081
    2 中国林业科学研究院林业研究所,北京 10091
    3 云南省林业科学院重点实验室,昆明 650204
  • 收稿日期:2004-11-29 接受日期:2005-06-25 出版日期:2006-11-29 发布日期:2006-01-30
  • 通讯作者: 顾万春
  • 作者简介:*E-mail:guwe@forestry.ac.cn
  • 基金资助:
    国家“十五”科技攻关课题(2001BA511B10);国家“十五”科技攻关课题(2002BA515B0403)

ALLOZYME VARIATION IN 10 NATURAL POPULATIONS OF PICEA ASPERATA

LUO Jian-Xun1, GU Wan-Chun2,*(), CHEN Shao-Yu3   

  1. 1 Research Institute of Forestry, Sichuan Academy of Forestry, Chengdu 610081, China
    2 Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
    3 Key Laboratory of Yunnan Academy of Forestry, Kunming 650204, China
  • Received:2004-11-29 Accepted:2005-06-25 Online:2006-11-29 Published:2006-01-30
  • Contact: GU Wan-Chun

摘要:

采用等位酶淀粉凝胶电泳和聚丙烯酰胺凝胶电泳技术对中国西部亚高山特有树种云杉(Picea asperata)10个天然群体的300个个体的遗传多样性和遗传分化进行研究。对8个酶系统17个酶位点(27个等位基因)的检测分析结果表明,10个位点为单态位点,云杉具有中等偏低的遗传变异水平。群体水平上的遗传多样性指标分别为:多态位点的百分率PP=29.41%~41.18%,等位基因平均数AP=1.4~1.6,平均期望杂合度Hep=0.06~0.131;种级水平的遗传多样性指标分别为:Ps=41.18%,As=1.2,Hes=0.138。10个群体的群体水平的观测杂合度为0.094 3,期望杂合度为0.096 4;10个群体中,7个多态位点的单位点的观测杂合度(Ho)的均值为0.229(变幅为0.142 9~0.342 9),期望杂合度(He)的均值为0.234 1(变幅为0.160 8~0.317 3), 云杉天然群体间遗传分化度(FST)为0.311,云杉群体间变异占总变异的31.1%,基因流低(Nm=0.553 9),说明群体间的基因交流有限。异交率高(t=0.957),近交率低(Fis=0.005),这些研究结果表明:云杉群体间等位基因的频率分化显著,其它云杉属树种基因的渐渗、群体微生境差异和不同强度的选择压力可能是造成群体间分化显著的主要原因;Fdh-2-B基因与综合生态梯度值呈显著的负相关(r=-0.661 1*),He与经度呈显著负相关(r=-0.683*),云杉群体间的地理和遗传距离相关不显著。10个群体均含有绝大部分等位基因,且群体间分化很大,应加以重点保护和管理,作为云杉种质资源原地保存的基地和该树种进一步遗传改良的重要育种群体。

关键词: 云杉, 天然群体, 遗传多样性, 等位酶变异

Abstract:

Picea asperata is an important tree for the production of pulp wood and timber and a prime reforestation species in western China. P. asperata occurs in the alpine and canyon regions of northwestern Sichuan Province and southeastern Gansu Province (100°-105° E, 30°-35° N), which are important water self-restraint regions. The genetic diversity of ten populations ofP. asperata in the western part of China was assessed using allozyme analysis by horizontal sliceable starch gel electrophoresis. Seventeen loci (27 alleles) of 8 enzyme systems demonstrated relatively low levels (mean He=0.096) of genetic variation within populations with values of PP=29.41% - 41.18%, AP=1.4 - 1.6 and Hep=0.06 - 0.131; at the species level, the genetic diversity of P. asperata (Ps=41.18%, As=1.2, Hes=0.138) was lower than the mean value of long-lived woody angiosperm species (Ps=59.5%, As=2.10, Hes=0.183). Genetic diversity is generally the result of long-term evolution. The low level of genetic variation present in P. asperata populations may be due to severe contractions in the area of distribution and population size during the last glacial period. Wrights F statistics analysis indicated that Fis, a measure of deviation from random mating within the 10 populations, was 0.005 suggesting deviation from Hardy-Weinberg equilibrium and a slight (homozygosity) excess in some populations. The higher level of differentiation (Fst=0.311) among populations than those of other long-lived woody plants may have resulted from factors such as habitat fragmentation, introgression from another species, variation in environmental conditions and differing selection pressure. Low level of gene flow (Nm=0.553 9), low level of inbreeding (mean Fis=0.005), and high level of outbreeding (Fis=0.005) could be caused by environmental deterioration and human disturbance, including over-harvesting. There were significantly negative correlations between Fdh-2-B gene and ecological gradient value (r=0.661 1*), as well as between expected heterozygosity (He) and longitude (r=0.683*). It was worth noting that the 10 populations harbored the majority of alleles and had higher genetic diversity suggesting that these populations in particular should be conserved in situ and form population used for tree improvement.

Key words: Picea asperata, Natural populations, Genetic diversity, Allozyme marker