The Anlysis Of Combining Ability And Heterotic Grouping In Superior Heading Chinese Cabbage Lines

In this study,the all-round hybridization design was used to study the combining ability and the hybrid's growth vigor of agronomic traits and economic traits in 10 superior inbred lines selected by the Chinese cabbage research group of Northwest A&F University.Then the SCA-Yang's,the SCA method and cluster analysis were used to divide the heterotic grouping,which will provide effective reference materials for the division of heterotic grouping in Chinese cabbage.The main findings obtained as follows: 1.There are significant differences between the orthogonal combination and reverse cross combination of Chinese cabbage and high correlation between traits related to yield.Except for the condensed stem length and the leaf costa thickness,the average value about each trait of the orthogonal combination is higher than the reverse combination,and the maximum and the minimum are different between the orthogonal combination and reverse cross combination.These phenomena suggest that cytoplasmic genes have a certain effect in these traits.Correlation analysis of the traits showed that traits were significantly correlated except for the condensed stem length and the leaf costa thickness.And the correlation between gross weight and net weight was the highest,reaching 0.909.2.The 14 traits' heterosis performance of Chinese cabbage inbred lines was clarified.In the mid-parent heterosis and the high-parent heterosis,the positive advantage ratio of the orthogonal combination is higher than that of the reverse cross in the 11 traits such as gross weight,net weight,leaf ball longitudinal diameter and transverse diameter and so on,except for leaf costa thickness,Plant height,and Plant width.In the ranking of the heterosis index,the outer leaf number,plant width,the largest outer leaf length,the largest outer leaf width,and the condensed stem length have an obviously differences between the orthogonal combination and reverse cross combination,indicating that the cytoplasmic genes have a relatively large influence on these traits.3.Screen out combinations with strong heterosisThe combination with the highest gross weight and net weight heterosis was 15S964× 14S96.The combination had no high-parental heterosis in the width of lesf costa and the length of the condensed stem,but it had high high-parent heterosis and excellent performance in 12 traits such as gross weight,net weight,plant height and plant width.The high-parental heterosis index of gross weight could reach to 185.19%,and net weight high-parent heterosis index coulad reach to 177.63%.4.The parents with high general combining ability and the hybrid combinations with high special combining ability are selected.Comparing the general combining ability of 10 excellent inbred lines in gross weight,net weight,longitudinal diameter,transverse diameter,leaf costa thickness and maximum outer leaf length,it was found that the general combining ability was higher when 13S93 and 15S964 were used as female parent,and 14129,14S256 and 09S602 were used as male parent.According to the analysis results of special combining ability,the special combining ability effect of 15S964×14S96 14S256×13S93 was higher in the yield traits such as gross weight,net weight,plant height and plant width.5.The heterotic group was initially dividedFor the traits about yield,the 10 excellent inbred lines in this study were divided into three groups,group one: 15S964,13S93,group two: 15S1094,14S256,group three: 14S96,09S602,15S1063,14S568,14S346 And 14S129.