Analysis Of Genetic Diversity And Construction Of Primary Core Collection Of Populu Deltoids

Populu deltoids, natived to North America along the Mississippi River, is the important forest tree species in North America. It has fast growth, good material, strong resistance and wide adaptability, is an important fast-growing timber species. This article, P. deltoids germplasm samples were collected, using modern molecular techniques to genetic diversity research and its core collection construction, provided the scientific basis of poplar species. By the use of SSR molecular markers, this paper carried out genetic diversity of research about Populu deltoides germplasm resources and constructed the core collection.The results obtained are as follows:1. A total of 89 alleles were detected using 24 SSR loci in 124 P. deltoides clones, showed 100% polymorphism, with an average allele number of 3.83 per locus (range:2～6).2. By the application of SSR markers, it was carried out the genetic diversity analysis of the 124 germplasms of Populu deltoides. By use of PopGene 32 software, it was caculated the genetic similarity coefficient of the 124 germplasms of P. deltoides. The resulits of SSR polymorphism analysis were as follows:effective number of alleles, Nei's gene diversity and Shannon's information was 1.3028～4.4644,0.2324～0.7760and 0.4454～1.5463. This indicated that there were the large SSR variation and high polymorphism between the 124 germplasms of P. deltoides. Clustering results showed that 21 sib-families could be divided into two differrent large categories obviously.The 35,40,47,70 and 74 sib-family were classed into each other, because of they have one or two clones only.The classification result of other sib-families were match for their originated place.3. Based on the analysis of genetic diversity, the core collection of P. deltoids was constructed using the existing germplasm resources. By use of PopGene 32 and SAS software using stepwise clustering and random methods, construct core collection of 179 germplasms of P.deltoides. Accrding to different sampling rate of 30%,20%,15% and 10% the primary core collections with 54,38,27and 18 biotypes were constructed. By using statistical software SAS and combining with observed number of alleles, effective number of alleles, Nei's genetic diversity index and Shannon's information index to evaluate and make t test of two groups core collection, the results showed that the 27 core collections of P.deltoides could conserve the genetic diversities and structures of the primary collection.