关键词: 树木年轮, 大气, δ¹³C, 模型

Abstract: In this paper, inter-simple sequence repeats (ISSR) technique was applied to study the genetic diversity and genetic differentiation of six Magnolia officinalis populations in Sichuan Province. For the 159 individuals of the six populations, 10 ISSR primers yielded a total of 114 bands sized 150-2000 bp, among which, 93 bands (81.58%) were polymorphic. The number of the bands per primer yielded varied from 10 to 13, with an average of 11.4 bands. A relatively low genetic diversity was detected at population level (the percentage of polymorphic loci PPB=48.25%, Nei’s genetic diversity H=0.189, and Shannon’s information index  I=0.277). However, the genetic diversity at species level was relatively high (PPB=81.58%, H=0.320, and I=0.469). The coefficient of genetic differentiation (G_ST) among populations was 40.42%, and the results of molecular variance analysis indicated that the genetic differentiation occurred mainly within populations (63.18%). The gene flow between M. officinalis populations was 0.737, and the average genetic distance was 0.211. The six populations were divided into three groups, according to UPGMA. Structure analysis showed that the genetic structure of the M. officinalis populations had the characteristics of independence.

Key words: Tree ring, Atmosphere, ¹³C, Model