Analysis On Heterosis And Combining Ability Of Waxy Maize DH Lines

In this experiment,6 waxy maize DH lines were obtained through DH breeding techniques,and 30 waxy maize cross combinations were obtained by combining with 5 common waxy maize inbred lines according to incomplete double crosses.Using SSR molecular marker technique to analyze the genetic distance of waxy maize DH lines,and cluster analysis of waxy maize DH lines.Through field investigations and quality testing experiments,the heterosis and combining ability effects of the main characters of waxy maize parents and their cross combinations were analyzed.The main findings are as follows:1.20 pairs of SSR core primers all had good amplification products.A total of 81 allelic variants were detected in 6 waxy maize DH lines,and each locus detected a range of 2-8 changes with an average of 4.05.The genetic distance of 6 waxy maize DH lines was between 0.5107 to 0.8572 with an average of 0.7332.The genetic distance between CH3 and CH5 is the largest,and the genetic distance between CH4 and CH5 is the smallest.Six waxy maize DH lines were divided into three groups: Group I included CH4 and CH5 two materials;Group II included CH1,CH2 and CH6 three materials divided into two subgroups,and subgroup II1 included CH1,subgroup II2 included CH2 and CH6;Group III included CH3.2.There are significant differences among the main traits of the 11 waxy maize parents and 30 waxy maize cross combinations,and the trait values of single trait have a wide distribution range.The average advantage and super-parent advantage of waxy maize cross combinations all have a wide range of variation.Except for the skin residue rate and crude starch content of super-parent advantage are more negative than positive,and the other traits in average advantage and super-parent advantage are both positive than negative.The hybrid combinations with strong heterosis are N3,N5,N7,N10,N20,N26 and N27.Heterosis index ranking for each trait: Axle weight > single ear weight > grain number per row > ear height > rea ear length > ear length > plant height > skin residue rate > axis diameter > stem diameter > ear width > ear row number > crude starch content > amylopectin content.3.11 parts of waxy maize parents,the GCA of 6 parents are more positive than negative and 5 parents are more negative than positive,the GCA of CH6 has most positive value,the GCA of C3 has most negative value.The frequencies of occurrence of hybrid combinations ranked in the top five for SCA were counted,and the frequencies of N30,N5,N27,N2,N26,N15 were high,the comprehensive traits of them were outstanding.The parents with higher combining ability were mated with CH1,CH3,CH6,C1,C2,and C5,and the SCA of other hybrid combinations that mated by these parental groups were also higher,indicating that their mating ability was Stronger.