Study On Genetic Improvement For Betula Luminifera

Genetic structure were studied for six natural populations of Betula. luminifera by AFLP molecular marker. On the other hand, in order to study the seedling growth , 62 families including 12 provenances were collected from main growing regions , including Zhejiang, Sichuan, Guang xi, Fu jian, Gui zhou provinces et al. Afforestation trials were conducted in Sui chang and Kai hua, the results showed that:1. There was high genetic diversity in species B. luminifera and mean genetic diversity (h)was 0.2713, while at total species level ,The Shannon diversity index (I) was 0.4679, genetic diversity (HT) was 0.3109. The analysis of molecular variance revealed that there was significant differentiation among populations, most variation was existed in inner population, the percentage was 88.15%. The genetic distance between population LA and other 5 population had the high value, the lowest was between population JX and population GX.2. The results of variance analysis were showed that very significant differences between families within a provenance on (seedling) height and (basal) diameter, 11 and 8 superior families as fast-growing were selected in Sui chang site and Kai hua site by 20% selection rate respectively, and most of them came from Du jiangyan and Qiong lai provenance in Si chuan. The results was was similar to results of seedling selection, which inferred that superior provenance was existed. Furthermore, more genetic gain would be gotten by the selection of superior individuals.3. Based on genetic stability in two trial sites, mutual effect between family and site was significant. Height growth as the main selective index, combined with breast diameter performance, based on fast-growth and stability of all families, 6 families were selected ,which were suited for growing in two sites. Moreover, 6 families were selected , which grew well in Sui chang and similar regions.4. Based on genetic structure analysis for natural population of B. luminifera, study on families trial from different provenance and superior individual selection , combined with the distribution feature of natural resource , and character of flowering and fruiting .The strategy on genetic improvement was proposed and prospect on new variety selection further for fast-growth, selected timber.