Analysis Of Germplasm Phenotypes And Molecular Genetic Diversity Of Different Safflower (Carthamus Tinctorius L.) Genotypes

Safflower(Carthamus tinctorius L.),also known as grass safflower and thorn safflower,is an annual or biennial herb of the genus Carthamus in Compositae.After long-term natural selection and artificial cultivation,safflower has formed a rich type of germplasm resources,but the current evaluation and research of safflower germplasm resources are still in the primary stage,and the phenotypic characters are easily affected by the environment,which leads to the confusion of safflower germplasm classification,and molecular markers are not easily affected by the environment,and the results are reliable and reproducible.In this study,ISSR,SCoT molecular markers combined with phenotypic traits are used to analyze the genetic diversity of 228 safflower germplasms,laying the foundation for safflower molecular marker-assisted selection breeding.In this research,we got the following conclusions:1.Through the analysis of the genetic diversity index of phenotypic traits,the genetic diversity index of 12 quantitative traits ranges from 1.74 to 2.07,of which the plant height is the highest,which is 2.07,and the total weight of the cone is the lowest,which is 1.74,the genetic diversity index ranges from 0.48 to 1.65 in flower color and other traits.Among them,the leaf types are the highest,which is 1.65,and the seat is the lowest,which is 0.48.Principal component analysis shows that the cumulative contribution rate of the first three principal components is 79.650%,and the eigenvalues of plant height,total number of branches,grain number of terminal fruit,weight of terminal fruit,total number of cones per plant,total weight of cones per plant and number of secondary branching fruit are larger.It can be used as an important phenotypic index to judge the germplasm classification of Safflower.2.Ten polymorphic SCoT primers were selected for PCR amplification of 228 Safflower germplasm,and 68 polymorphic bands were obtained.POPGENE software analysis shows that the percentage of polymorphic sites(PPB)of SCoT is 100%,the number of observed alleles(NA)is 2.0000,the number of effective alleles(NE)is1.5903,the Nei’s gene diversity(He)is 0.3429,and the Shannon’s information index(I)is 0.5129.SCoT molecular markers can be used to study the genetic diversity of safflower germplasm.The safflower germplasm is divided into four populations: East Asia,South Asia,West Asia,and North Africa according to geographic location.The number of polymorphic bands of the four populations range from 56 to 68,and the ratio of polymorphic bands range from 82.35% to 100%.The Nei gene diversity(H)range from 0.2921 to 0.3419,and the range is 0.0498.East Asia is the highest(0.3419),West Asia is the second(0.3311),while South Asia and North Africa are close(0.2978 and 0.2921),respectively.Comprehensive analysis shows that East Asia has the highest genetic diversity,followed by West Asia,South Asia and North Africa.The SCoT analysis shows that the coefficient of genetic differentiation(GST)is0.0514 and the gene flow Nm is 9.2335,indicating that there is frequent gene exchange among different populations of Carthamus tinctorius.The genetic variation among populations is small,but the genetic variation within populations is large.3.16 pairs of polymorphic ISSR primers are selected from 105 pairs of ISSR primers,and 124 polymorphic bands are obtained by PCR amplification of 228 safflower germplasms with 16 pairs of primers,The percentage of ISSR polymorphic loci(PPB)= 100%,observed allele number(NA)= 2.0000,effective allele number(NE)= 1.5496,Nei’s gene diversity(He)= 0.3301,Shannon’s information index(I)= 0.5008 are obtained by POPGENE software analysis.228 safflower germplasms are divided into four populations according to their geographical location.The number of polymorphic bands of the four populations range from 101 to 124,and the polymorphic ratio range from 81.45% to 100%.The Nei gene diversity(H)in East Asia is the highest(0.3316),West Asia is the second(0.2913),while that in North Africa and South Asia is close(0.2817 and 0.2789),respectively,Comprehensive analysis shows that East Asia has the highest genetic diversity,followed by West Asia,South Asia and North Africa.ISSR analysis shows that the genetic differentiation coefficient(GST)was 0.0558,and the gene flow Nm is8.4686.The results show that the genetic variation among the four populations is small,but the genetic variation within the populations is large.4.when the square Euclidean distance is 3.7,228 germplasm resources are divided into four groups by phenotype cluster analysis;ISSR cluster analysis divides safflower germplasm into four groups when the genetic similarity is 0.71;when the genetic similarity is 0.69,safflower germplasm can be divided into five groups.The safflower germplasm in the three clustering results group I performed well,and Nine varieties of Safflower germplasm with outstanding yield are screened from their common varieties,including 5 Xinjiang germplasm(No.102,104,198,203,204)and4 Indian germplasm(No.201,213,214,215).