Screening Of Core Primers And Genetic Diversity Of Germplasm Resources In Kenaf(Hibiscus Cannabinus L.)

Kenaf(Hibiscus cannabinus L.)(2n=36)belongs to the Hibiscus family Hibiscus,a fiber crop that is annually pollinated by cross-pollination.Kenaf’s heterosis is very obvious and has stronger adaptability,more tolerance ofsalt-alkali and larger biomass than conventional varieties.In this study,154 germplasm resources from 16 countries were used as materials.On the one hand,core primers were screened in kenaf.On the other hand,fertility and genetic diversity of kenaf germplasm were analyzed,and core primers were used to construct fluorescent DNA molecular identification card of 24 representative germplasm.These will facilitate creating new cytoplasmic male sterility germplasm and screening excellent hybrid combinations.The main results are as follows:1.In order to assess the phenotypic diversity of kenaf germplasm resources,the variation analysis on 9 phenotypic traits of 154 germplasm resources was conducted,and the correlation and principal components analysis of 7 quantitative traits were analyzed in this study.The variation characteristics of main agronomic traits among different germplasms were different,and the variation coefficient varies from 8.72% to 52.17%,which was rich in variation among these germplasms.Correlation analysis showed that,except for the fresh skin thickness and the number of growth days and flowering days,correlation among other agronomic traits reached significantly at the 0.05 and 0.01 level.The cumulative contribution rate of the two principal components,including two main factors of fiber yield and growth stage,extracted by principal component analysis reached 73.698%.Combined with geographical sources,73 kenaf germplasm resources were randomly selected for cluster analysis of agronomic traits.At the Euclidean distance of 0.112,the materials could be divided into 7 groups,and the agronomic characteristics of different groups were significantly different.2.In order to screen the core primers of kenaf,based on the 1352 pairs of primers developed previously in the laboratory,24 different materials from 154 germplasm resources for polymorphism assessment were selected in this study.Combined with genomic data,44 pairs of core primers with clear amplified bands and high polymorphism were selected.2 or more core primers were distributed evenly in each chromosome.151 polymorphic bands were obtained by 44 pairs of core primers in 24 germplasm resources.The average of polymorphism information content(PIC)was 0.6441,and the maximum was 0.9052.These core primers can be used in genetic diversity of germplasm resources.3.To identify the sterile cytoplasm of 154 kenaf germplasm resources,the wild type CMS cytoplasmic SNP molecular tag was used for amplification in kenaf.The results showed that clear bands were detected in the three germplasms of K5(Lai yang hong ma),K11(Hong3A)and K13(Fu hong hang 1A).K11 and K13 were all sterile,which was a typical wild-type sterile line.However,the fertility separation ratio of K5 germplasm was 1:1,which initially showed the characteristics of nuclear male sterility.Its male sterility and genetic characteristics need to be further identified.Among the 154 kenaf germplasm resources,there were only 3 wild-fertile sterile cytoplasms,accounting for 1.94%.And others were fertile germplasms.4.To analyze the genetic diversity of kenaf germplasm based on molecular markers,core primers,including 39 pairs of nuclear genome primers and 5 pairs of chloroplast genome SSR primers were used to conduct genetic diversity of 73 germplasms.The dendrogram was drawn by UPGMA.Germplasm resources were clustered into 4 categories at a genetic similarity coefficient of 0.756 using the core nuclear primers,and germplasm resources were clustered into 4 groups at a genetic similarity coefficient of 0.788 using the chloroplast SSR core primers.5.The construction of DNA molecular identification cards for germplasm resources was helpful to protect varieties.The molecular weight data obtained by capillary electrophoresis were encoded in the form of numbers and English letters.And 7 pairs of fluorescent core primers were selected to construct DNA molecular identity cards of 24 representative germplasm in the form of strings,bar codes and two-dimensional codes.Combined with basic information of various germplasm resources using an online QR code generator,the simple and easy-to-identify DNA molecular ID cards of these germplasm were obtained.These results will provide gene resources and evidences for heterosis utilization and hybrid variety protection in kenaf.