| Xinjiang is the largest place for planting lavender in the China.There are 50 years of cultivation history with abundant germplasm resources.Lavender is widely used in medicine,food and daily supplies.The genetic diversity of lavender is great significance to the collection,preservation and classification of lavender germplasms.In this study,the survey of phenotypic traits and genetic diversity were conducted on 65 lavender germplasms in Xinjiang.The results of ISSR-PCR and SRAP-PCR reaction systems optimization,screening of ISSR and SRAP primers and analysis of genetic diversity will be theoretical basis for the identification,classification and preservation of lavender germplasms,and will provide a scientific basis for lavender breeding.The main research results are shown as follows:1.The phenotypic characters of 65 lavender germplasm resources were investigated,and the genetic diversity thereof was evaluated by principal component analysis and cluster analysis.The results showed that the phenotypic characters of the 65 lavender germplasm resources varied greatly,and the variation coefficient was 5.98%to 38.64%.The results of the principle component analysis showed that the top three principle components represented 63.893%of the information of the phenotypic characters of the 65 lavender germplasm resources,wherein the contribution rate was 38.657%,14.608%and 10.628%respectively.The results of cluster analysis showed that the 65 strains of lavenders could be divided into 3 groups and 9 subgroups when the genetic distance was 4.0 and 12.0,wherein the 1st,2nd,3rd and 4th subgroups were included in the first group,the 5th subgroup was included in the second group and the 6th,7th,8th and 9th subgroups were included in the 3rd group.2.In 25 μL of SRAP-PCR system,the concentration of Mg2+ was 3.0mmol/L,of dNTPs was 0.32mmol/L and of the primers was 0.24ummol/L,the DNA template quantity was 60ng,the dosage of Tap DNA polymerase was 0.4 U;11 core premiers were screened out from 153 SRAP primers and 192 amplification sites were obtained.Of all the amplification sites,182 were polymorphic sites,and the polymorphic percentage was 94.79%.Each core primer had 12 to 22 polymorphic sites with an average of 16.54.The analysis on genetic similarity and genetic distance was carried out for the 65 lavender germplasm resources by using the POPGENE1.32,wherein the range of the genetic similarity was 0.5104 to 0.8854 with an average of 0.2002,the variation range of the genetic distance was 0.1217 to 0.6931 with an average of 0.3373;the numbers of alleles(Na)and effective alleles(Ne)of the genetic diversity parameters were respectively 1.9635 and 1.5556;the Nei’s gene diversity index(He)was 0.3203,and the Shannon information index(I)was 0.4793.The results of the cluster analysis and the principal component analysis were consistent.The tested germplasm resources can be divided into four groups,wherein 35 germplasm resources were included in the I group,1 in the Ⅱ group,and 28 in the Ⅲ and Ⅳ groups respectively.3.The best reaction system of ISSR-PCR was established.In the total volume(25.0 μL)of the ISSR-PCR,10 x buffer was 2.5 μL and the concentration of Mg2+ was 1.5mmol/L,of dNTPs was 0.45mmol/L and of primers was 0.7μmol/L,theDNA template quantity was 100ng,the dosage of Tap DNA polymerase was 0.1 U;15 core premiers were screened out from 100 ISSR primers and 205 amplification sites were obtained.Of all the amplification sites,168 were polymorphic sites,and the polymorphic percentage was 81.95%.Each core primer had 8 to 19 amplification sites with an average of 16.66,and had 4 to 17 polymorphic sites with an average of 11.20.The genetic similarity and distance analysis conducted by using the POPGENE1.32 showed that the coefficient of the genetic similarity was 0.6244 to 0.9317 with an average of 0.3712,the variation range of the genetic distance was 0.0707 to 0.5108 with the average of 0.1509,the number of alleles(Na)was 1.8488,the number of effective alleles(Ne)was 1.4362,the Nei’s gene diversity index(He)was 0.2536,and the Shannon information index(I)was 0.3846.The results of the cluster analysis and the principal component analysis were consistent.The germplasm resources can be divided into two groups,wherein 36 germplasm resources were included in the Ⅰ group,and 29 in the Ⅱ group.4.The correlation coefficient r(r=0.8329)between the two groups of similarity coefficients calculated by ISSR and SRAP reached a significant level,which showed that the ISSR marker technology and the SRAP marker technology were high in consistency and reliability for analyzing the genetic diversity of lavenders. |
PDF Full Text Request