Collection and genetic diversity analysis of wild germplasm in Salix matsudana

ObjectiveThe study was to explore genetic diversity within the species on the basis of surveying and collecting Salix matsudana germplasm in Shandong Province of eastern China.

MethodContrasted experiment at nursery stage was built and seedlings of 2-year-old were used as materials for phenotype observation and molecular marker of genetic diversity.

ResultResults showed that color of stem and branchlet was discovered as kelly-green, grayish-green, green, grayish-brown, reddish-brown and brown; stem form showed from up-right to strongly curve; branchlet form was from upswept to straight to droop. Height ranged from 1.2 to 5.5m with ground diameter from 0.6 to 4.6cm after the same growth cycle. Similar situations also existed in length, width and area of leaves. Leaf length ranged from 8.5 to 18cm, leaf width ranged from 0.92 to 3.49cm and leaf area ranged from 6.258 to 33.584cm². Extreme discrepancy of leaf length and area were mainly from within clones, while those of height, ground diameter and leaf width were mainly from among clones. Main source of variation was from among clones, and trait differentiation among clones was the reason of segregation of traits of S. matsudana, with a contribution rate at more than 80%, meaning that differentiation among clones was the key for differentiation in the spices of S. matsudana. Results of AFLP showed a real high percentage of polymorphism on observed locus and average value could be 99.5%. Diversity index revealed that Nei's index was 0.2322 and Shannon index was 0.3746, which meant all individuals could be the same species and principal component analysis and cluster analysis supported this conclusion.

ConclusionExperiments showed that there exited abundant diversity in both phenotype and genotype traits, which proved Salix matsudana was great material on selection and cross breeding.