Phenotypic Clustering And SSR Clustering For Classification And Heterosis Of Inbred Lines In Popcorn

Sixty inbred lines of popcorn with genetic background difference were selected in this paper.The inbred lines were divided by phenotypic clustering and SSR clustering,and 12 popcorn inbred lines wit h large genetic differences were selected as experimental parents by cluster analysis.According to the design method of incomplete diallel crossing,35 cross combinations were crossed.The F1 generat ion and parent inbred lines were investigated,the data were analyzed,and the heterosis analysis of 13 characters was carried out.Analysis of general combining ability and special combining ability.The test results are as follows:1)measuring the phenotypic shape of 60 inbred lines,the genetic distance between different inbred lines was calculated,and cluster analysis was made according to the value of genetic distance.At genetic distance of 0.79,60 inbred lines were divided into five groups.There were 8 inbred lines in 4th class and 8 inbred lines in 5th class.2)A total of 87 alleles were detected in 60 inbred lines of popcorn by PCR amplification with 18 pairs of primers.The average number of variant alleles detected at each locus was 4.83.The PIC value of 60 popcorn inbred lines was 0.584.By cluster analysis,60 inbred lines were classified into five categories.19 inbred lines,mostly native,3 inbred lines in the third category,8 inbred lines in the fourth category,and 4 inbred lines in the fifth category.3)By sorting out the results of two kinds of cluster analysis,it can be concluded that the two results are basically consistent,and there are individual individuals,and the inbred lines selected from the two results of cluster analysis are selected as the parents inbred lines of the experiment.4)Through the analysis of the characters of 35 cross combinations,it was shown that the heterosis of F1 generation was universal,and the positive part of the heterosis or super parent heterosis of most traits was larger than that of negative part.The results indicated that there were dominant combinations in 35 cross combinations selected by 12 parents in this experiment,and Z42×Z55,Z1×Z55,Z29×Z20,Z23×Z35,Z28×Z20,Z51×Z35,Z23×Z35 had strong superiority in the quality characters including explosive flower rate and expansion ratio.The yield of Z42×Z55,Z1×Z55,Z29×Z20,Z28×Z20,Z51×Z35,Z23×Z35 was stronger than that of popcorn in the comprehensive plot.The hybrid Z42×Z41,Z42×Z35,Z23×Z41,Z51×Z41,Z29×Z41 had strong heterosis.5)The special combining ability analysis of general combining ability of inbred lines and hybrid combinations.The analysis shows that if one with special traits of hybrid force is positive,the general combining ability of their parents were also positive for the general or with a parent together as positive additive genetic effects with general decision force,if the general combining ability of a trait of parents,which matched the hybrid offspring traits are influenced by it.From the above analysis,characters of parent Z35,good Z20,general Z42 with the three inbred lines of force is positive,so in the breeding of good quality popcorn varieties combination It can be used as an excellent parent.