| In order to understand the genetic diversity of different capsicum germplasm materials.Cluster analysis of 250 capsicum germplasm based on the genetic diversity of phenotypic traits and polymorphism of SSR markers were carried out,respectively,and the correlationship of the two clustering method were compared;17 pepper parents were selected to prepare hybrid combinations,and the genetic distance of the parents was obtained based on phenotype and SSR markers to predict the heterosis of F1 generation.The results will provide theoretical basis for evaluation of germplasm resources、capsicum germplasm innovation and capsicum germplasm in variety improvement.The main results are as follows:1、The coefficient of variation of 21 quality traits ranges from 16.49%to 104.65%,the fruit shoulder trait has the largest coefficient of variation,the Shannon diversity index ranges from 0.37 to 2.22,and the fruit-shaped Shannon diversity index has the largest;the coefficient of variation of 14 quantitative traits ranges from 23.59%-110.03%,the single fruit weight variation coefficient is the largest,the Shannon diversity index ranges from 1.08 to 2.11,and the plant size Shannon diversity index is the largest;the cumulative contribution rate of the first 9 components in the principal component analysis was 66.98%,which were called yield factor,ripeness factor,fruit shape factor,plant type factor,appearance Factor,fruit color factor,leaf color factor,color factor and leaf shape factor;cluster analysis divided the test pepper into 5 categories,of which fruit shape and single fruit weight are the main factors that affect the clustering results.2、Screened 20 pairs of polymorphic primers to analyze the genetic diversity of pepper,the number of effective alleles(Ne)was 1.05～2.86,with an average value of 2.08;the gene diversity index(Nei’s)was 0.05～0.65,with an average 0.47;observed heterozygosity(Ho)is 0.0052～1.00,average value is 0.56;expected heterozygosity(He)is 0.05～0.65,average value is 0.46;Shannon index(I)is 0.13～1.07,average value is 0.78;SSR marker cluster analysis also divided the test peppers into 5 categories.3、Mantel correlation was compared between the two clustering results based on phenotypic traits and SSR markers.It was found that there was no correlation between the two methods(r=-0.09).4、According to the phenotypic data of the parents and hybrid combinations,the mid-parent advantage of the first flower node is between-36.37%～38.75%,with an average of-14.58%,and the super-parent advantage is between-43.10%～38.75%,with an average of-24.53%;the parental advantage of plant height is between-58.69%～-15.79%,with an average of-40.11%,and the superparent advantage is between-59.67%～-23.76%,with an average of-48.12%;Between-69.25%～-16.45%,the average is-45.12%,the super-parent advantage is between-69.62%～-28.49%,the average is-50.56%;the single-fruit weight middle-parent advantage is-84.31%～288.23%Between,the average is 17,89%,the superparent advantage is between-89.96%-273.8%,the average is 15.01%;the minimum parental advantage of the fruit diameter is-52.33%,the largest is 64.70%,the average is 1.29%,the super The parental advantage is between-69.18%and 50.38%,with an average of-18.88%;the range of the parental advantage of fruit longitudinal diameter is-21.23%to 175.91%,with an average of 41.37%,and the superparental advantage is between-37.41%and 126.25%,With an average of 13.33%;the mid-parent advantage of thick pulp is between-47.28%and 60.37%,with an average of 9.27%,and the super-parent advantage is between-54.53%and 55.48%,with an average of-6.13%.5、Correlation analysis between the genetic distance of the parents and the heterosis of the F1 generation showed that the genetic distance of the phenotypic traits was not significantly correlated with the heterosis of the first flower node,plant height,plant width,single fruit weight,fruit longitudinal diameter and flesh thickness of the F1 generation.There is a very significant negative correlation with the heterosis of fruit diameter,the genetic distance of the parents of SSR markers is not significantly related to the heterosis of plant height,plant width,single fruit weight,fruit transverse,fruit longitudinal and thick flesh,and the first flower of F1 There is a significant negative correlation between the mid-parent advantage of node(r=-0.68*). |
