The Study Of Drought Resistance And Core-Collection Construction Of Salix

In order to explore the differences of the ecophysiological adapations of four Salix clones, the dynamic changes of osmotic adjustment and protective enzyme activities were studied under drought stress by pot experiments. The results showed the relative electrical conductivity and malondialdehyde increased with the increase of drought stress. However, proline, soluble sugar and the activities of peroxidase and superoxide dismutas increased under gradual drought stress.The result of principal component analysis on all ecophysiological indexes suggested the order of the four Salix clones on drought resistance from big to small in turn was A44, A87, A95, A97.Based on AFLP markers, studying the genetic diversity and the core-collection construction of 119 Salix gathered from inside and outside Shandong province. From 64 pairs of Pst I/Mse I primers, 9 pairs of primers are selected with the clear stripes, highly polymorphic and strong repeatability.8 primer combinations produced a total of 1307 bands, 1304 of which were polymorphic with a polymorphism percentage of 99.75 %. The value of Na, Ne, H, I were 1.9988, 1.2157, 0.1401 and 0.2346, which indicated that it had a high genetic diversity among Salix germplasm. 241 specific bands amplified from 85 germplasm of 119 Salix single plants, which were all single and accounted for 18.48% of total polymorphic bands. Genetic similarity coefficient of Salix germplasm changed from 0.3500 to 0.7899 with the average was 0.616. In the cluster result, Genetic similarity coefficient of Salix germplasm was closer with geographic origin, but there was no strict limits both different and geographic origin.Core collection were constructed by using the strategy of sample proportional method and UPGMA clustering sampling method within subgroups after the grouping, and combined geographic origin and growth index. which reserved 34.45% samples of original collection with 41 resources. The reserved rate of number of polymorphic loci and percentage of polymorphic loci were 93.25 % and 99.834%, and the reserved rate of observed number of Na, Ne, H, I were 99.81%,100.92%,106.42%,107.83 respectively. The result of t-test,s showed that the genetic diversity indexes didn,t have significant difference between the contruction of core collection and original collection, which indicated that the genetic diversity of core collection could stand for what of the original collection.