[Analysis on SNPs linked with wood properties of Populus nigra L. gene resources].

In this study, 115 Populus nigra L. collected from Europe were used as materials. They were detected for SNPs of genes linked with lignin and holocellulose (4CL, PAL and CesA2) by TaqMan technology and correlations between SNPs and wood properties (the wood speciely gravity, fiber length, fiber width, microfibre angle, lignin, holocellulose content and a-Cellulose content) were also studied. results showed that (1) 27 SNPs were obtained in the genes, such as 4CL, PAL and CesA2 associated with lignin synthesis. Among them, 17 SNPs were transition (A-G, C-T), 10 SNPs were transversion (A-C, G-C, G-T, and A-T). (2) Three of the SNPs were discriminated, a significant negative correlation between holocellulose content of four-year old P. nigra and SNP1 was detected, and contribution ratio was 11.11%. SNP2 and SNP3 had no significant correlation with wood properties. (3) Wood properties of various genotypes of SNP1 were significantly different. CC and CT genotype relative to TT genotype had larger holocellulose content. SNP1 would be an efficient marker to choose P. nigra gene resources that have larger holocellulose content.

[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.