[SSR molecular markers related to wood density and fibre traits in poplar]

In this study, field experiment was carried out following the randomized complete block design with five replications in 1999. F2 population was derived from a cross between the female ZH3 and the male ZH1 (ZH3, ZH1 were selected from F1 individuals derived from the cross of Populus deltoides with P. cathayana, produced by HUANG Dong-Sen in 1973). Sixty-eight F2 populations, four F1 individuals (included ZH3, ZH1) and both parents (Populus deltoides and P. cathayana) were measured for wood densities, fibre lengths, fibre widths and fibre angles. The results indicated that the trait of fibre length has obviously heterosis, there may have positive effects among the genes controlling the trait of fibre length, but may have negative effects among the genes controlling the trait of wood density. Using the method of single factor variance, the SSR markers correlated with wood density, fibre length, fibre width and fibre angle were identified to be 5, 7, 4 and 2, respectively. There were some useful markers among the above traits in P. cathayana, such as PMGC2873-1 for wood density (its contribution was 4.88%), PMGC456-3, PMGC2702-2 for fibre length (their contribution were 22.96% and 9.17%, respectively), PMGC2408-1 for fibre width (its contribution was 7.18%), and PMGC2525-1 for fibre angle (its contribution was 16.59%), these markers might be useful for wood property improvement if using them correctly in breeding program.