Clustering Analysis Of Genetic Diversity In Eggplant Based On Morphological And ISSR Marker

Eggplant(Solanum melongena,L.)originated in Indian sub-continent and Asian tropics;it was domesticated in the region of Indian in earlier of age.It had a long cultivate history and very rich in germplasm resource in China,where it was recognized as secondary center of eggplant origin.The study on the genetic diversity of eggplant germplasm resources can benefit the conservation,classification, identification,genetic enhancement and effective utilization of eggplant germplasm resources.Currently,with the development of molecular marker,it was widely used in taxonomy of plant.ISSR(Inter-simple sequence repeat)as highly polymorphic and economic marker was used to test the genetic diversity evaluation among 55 eggplant germplasms in this experiment,the main results are as follows:1.The principal component analysis and cluster analysis was determined among 55 eggplant varieties on morphological traits.There are different extents of diversity on the different varieties.Among the different varieties,the variation coefficients of fruit shape exponent goes up to 74.41%,which is the important trait in the period of growth on eggplant.There were 18 principal components and 6 of them could explained 81.071%of the variance.Cluster analysis showed that the studied cultivars could be classified into 8 cluster,and the major clusters grouped cultivars of similar quantitative morphological traits.2.The establishment of the improved CTAB,is the ideal method of extracting DNA from the eggplant fresh leaves.The major steps were removed the impurity before broken cells,splited to release DNA,precipitated and separated DNA,so this method could be well applied to ISSR reaction and other means of testing requirements.3.Optimum system of ISSR amplification for Chinese eggplant.In 20μl reaction solution:Template 60ng,Primer 0.4μmol/L,400μM dNTPeach,TaqDNA polymerase 1U,3 mM Mgcl₂,2×buffer2.0μl;added to 20μl with ddH₂O.The amplified procedure was:Step1:94℃5min;Step2:94℃45s,59℃45s,72℃75s,40 cycles;Step 3:72℃10min,4℃preservation.4.10 effective primers were screened from 100 ISSR arbitrary primers,and a total of 107 fragments were amplified,129 of which were polymorphic(82.94% polymorphisms),the average number of fragment amplified by each primer was 12.9. The result of POPGENE analysis indicated that the average of Shannon's Information index was 0.4326,Nei's Gene diversity H was 0.2844,and effective number of alleles per loci was 1.4820 on all average.5.Based on the amount of fragment amplified by ISSR,genetic similarities, among the 55 eggplant germplasms,were calculated by SPSS12.0,which ranged from 0.02 to0.95,there were minimum similarity 0.02and maximum similarity 0.95. According to the data,a dendrogram of genetic relationship constructed by using Within-groups linkage method showed that all the tested eggplant germplasms were classified as two groups with the similarity coefficient of 0.97.Among of the second group,which includes only seven germplasm,are hybrids,was the smallest group, and the first group,which includes 48 germplasms,was the largest group,the rest germplasms were cluster into other groups.Furthermore,the first group was divided into three sub-groups with the similarity coefficient of 0.49.The first sub-group are consisted of 28 germplasm known;the second sub-group consisted of 4 germplasms, which cataloged as cultivar,and majority of them had a longer fruit shape.ISSR marker was corresponded with traditional classification on fruit shape on the sub—group grade.