Abstract:

Genetic variation was evaluated using phenotypic traits and RAPD markers in 8 natural populations of Betula luminifera from Fujian Province, China. The relationship between genetic variation and environmental factors was also examined. It was showed that the genetic variation of B. luminifera revealed by RAPD markers coincided well with those by phenotypic traits, and about 2/3 of the total genetic variation distributed within population while 1/3 among populations. The mean coefficient of variation (CV) of phenotypic traits of leaf, infructescence and seed was 0.063 2, 0.070 6 and 0.069 3, respectively. The CV of morphological index of leaf, infructescence and seed was much lower than those of other traits. The percentage of polymorphic loci (PPL), Neis gene diversity (h) and Shannon informative index (I) at mean population level were 65.27%, 0.246 1 and 0.362 8, respectively. The correlation analysis showed that there existed significant correlations between 15 phenotypic traits and environmental factors. The main phenotypic traits which were related with environmental factors, were leaf length/width, number of lateral vein, the angle of leaf base, seed wing width, weight of 1 000 seeds and infructescence length/width. The PPL, h and I were also significantly positively correlated with annual sunshine hours, negatively correlated with latitude/longitude and annual precipitation. The genetic distance between these populations (GD) was significantly correlated with their divergence of annual average temperature, however not with their geographic distance.

Key words: Betula luminifera, genetic variation, phenotypic variation, RAPD, habitat