GENETIC VARIATION ANALYSIS OF A TRIPLOID CLONAL SPECIES LILIUM LANCIFOLIUM BASED ON MORPHOLOGY AND SRAP MARKER AND THE VARIATION OF CLONAL RAMETS

摘要

Triploid Lilium.lancifolium is widely distributed in China and they can tolerated varied environment condition of China. Bulbils, as the only reproduction module for triploid L.lancifolium, have important impact on the population size and genetic diversity of this species. Little genetic variation studies have been done for triploid L.lancifolium of China. To obtain the first information of genetic variation and understand the promoting force of evolution in triploid L.lancifolium, SRAP marker and morphological traits were used to investigate the genetic variation of eight groups of wild triploid L.lancifolium from China, then we assessed the clonal variation using SRPA marker for six clonal ramet groups. Significant differences of morphological traits were detected among and within groups, and for most traits, the variation within group always higher than among groups. Ten sets of primer generated a total of 167 bands for all the wild materials and 75 were polymorphic with a polymorphic percentage of 44.91%. A higher level of genetic differentiation was detected between groups from same region (Gst=0.2862) than between regions (Gst=0.2210) suggesting a certain degree of irrelativity between genetic differentiation and geographic distribution. Two clustering approaches, unweighted pair group method for arithmetic averages and principle coordinate analysis, supported a division of the eight groups into two major clusters, and molecular variance analysis further determined the genetic structure and confirmed the 66% of total variance within groups. A total of 174 bands were produced by six clonal groups of 242 ramets and 46 were polymorphic with a polymorphic percentage of 26.43%. The polymorphic percentage of six clonal ramets groups ranged from 9.77% to 15.52% with an average value of 12.74. Within clonal ramet group, the level of genetic variation at different locus was significant different; among clonal ramet group, the level of genetic variation at same locus was significant different too. Considering the characteristic of obligate asexual reproduction of triploid L.lancifolium, we believed the genetic variation among ramets is the fundamental variation source of triploid L.lancifolium in China.