Analysis Of Genetic Diversity And Utilization Of Heterosis In Sweet Maize Germplasm Resources Using SSR Molecular Markers

This experiment conducted cluster analysis of agronomic traits and SSR molecular markers on 120 sweet corn inbred lines,and selected 14 sweet corn inbred lines with significant genetic differences from different groups as parent materials.According to incomplete diallel crossing design,48 hybrid combinations were assembled.Correlation analysis,principal component analysis,heterosis analysis,combining ability analysis,and genetic parameter analysis were performed on the parents and hybrid combinations.The main research results are as follows:1.The variation coefficient of 12 agronomic traits in 120 sweet corn inbred lines ranged from 9.25% to 168.52%,and the variation range of genetic diversity index was1.16-1.98;Among the 12 agronomic traits,the correlation between axle weight and single spike weight was the highest,followed by plant height and spike position.2.Both agronomic trait clustering and SSR molecular marker clustering divided120 sweet corn inbred lines into 5 groups,with similar clustering results but some differences.3.The highest correlation between agronomic and quality traits among 48 sweet corn hybrid combinations is the ratio of husk residue and 100 grain weight,followed by lutein and 100 grain weight.4.Principal component analysis extracted a total of 9 principal components,with a cumulative contribution rate of 81.99%;XB27,XB08 and XB36 are a combination of the top three overall scores5.The positive part of average heterosis and super parent heterosis is mostly greater than the negative part.XB37 shows higher heterosis in food quality related traits,XB36 and XB48 show higher heterosis in nutritional quality,and XB09,XB13 and XB17 show higher heterosis in agronomic traits and quality traits.6.The GCA analysis results indicate that 21033,21074,and 21099 can be used as hybrid combinations with good palatability,while 21010,21072,21074,and 21029 can be used as hybrid combinations with higher nutritional quality.7.The results of SCA analysis indicate that XB02 performs well in 20 traits,XB14,XB16,XB20,and XB43 perform well in edible quality traits,and XB13,XB30,and XB36 perform well in nutritional quality traits.8.The results of heritability analysis showed that plant height,ear position,single ear weight and axle weight were easily affected by environment;Except for the selection of shaft thickness and folic acid in the late generation,the other 18 personality traits should be selected in the early generation.