Gene Differentiation in Natural Population of Picea asperata and Sampling Strategies for Ex situ Germplasm Resource Conservation

The number and differentiation of alleles of Picea asperata(PA) natural population were studied by means of horizontal sliceable starch gel electrophoresis and vertical slab polyacrylamid gel electrophoresis to analyze the isozyme variation of 300 individuals from 10 natural populations (30 individuals per population) in its natural distribution area. On the basis of analyzing the allozyme bands, 17 loci and 27 alleles of 8 enzyme systems were detected. The mean number of alleles determined from the 10 natural populations was 24.7, ranging from 23 to 27. The number of essential alleles and widespread alleles were 19 and 7 respectively,accounting for 70.37% and 25.93% of total number of alleles detected. There was only 1 rare allele detected in Tiebu population, i.e.,Idh-2-C, accounting for 3.7% of all alleles detected. There was no obvious difference in allele frequencies among the 10 natural populations. However, there was some difference in essential allele frequencies at the same loci among the populations. Curve maps of gene capturing of isozyme marker at both population level and at individual level inside the population for germplasm resource conservation of Picea asperata(PA) natural population were established. It was showed by correlation analysis that there was a negative relationship(r=-0.661 1^*)between the gene frequency of Fdh-2-B and the ecological gradient value. The sampling strategy for the core gene resource conservation of Picea asperata(PA) natural population was made. It was indicated that 95%~99% gene resources of Picea asperata(PA) natural population could be conserved effectively by sampling 7 populations from Tiebu, Zuoni, Arba, Xiaojin, Rewugou, Fengxian and Qugu in the whole natural distribution area and 25 individuals per population randomly.