| In view of the problems faced by the breeding of fresh corn in China,such as the lack of effective identification of germplasm resources,the low breeding efficiency and the low quality,in this study the genetic diversity of 70 fresh corn were analyzed through SSR markers and then divided into different groups,at the same time the main quality traits were also analyzed by using the near-infrared spectrometer,which would provide theoretical guidance for the utilization of heterosis of fresh corn and the cultivation of new varieties with good quality.The main resluts were as follows:1.A total of 84 pairs of SSR primers were downloaded from MaizeGDB(https://www.maizegdb.org),and 50 pairs of primers with stable polymorphism were obtained through preliminary screening;Among 70 fresh corn samples,234 alleles were detected with 50 pairs of SSR primers,and 4-11 alleles were detected with each pair of primers,with an average of 4.68 alleles.The polymorphic information content(PIC)of each pair of SSR primers was 0.47-0.81,with an average value of 0.63.2.The genetic similarity coefficient analysis results showed that the variation range of the genetic similarity coefficient of 70 fresh corn was 0.24-0.78,with an average of 0.33.There were differences in the genetic diversity among different types of fresh corn.The highest genetic diversity was sweet corn,the lowest is sweet and waxy corn;The genetic similarity coefficients of sweet corn and sweet waxy corn were the highest and those of sweet corn and sweet waxy corn were the lowest.3.The UPGMA method was used to cluster 70 pieces of fresh come,and the influence of SSR primers on the classification of groups was discussed.The results showed that the number of primers and polymorphism had a great influence on the clustering analysis.Using 50 pairs of SSR primers,70 fresh corn could be divided into three groups:sweet corn inbred line,waxy corn inbred line and fresh corn hybrid.4.The content of protein,starch,water and fat in 66 fresh maize samples were determined.The quality analysis results showed that sweet corn 1048-b,WJH 13-b-b,WJH 8-b-b-1,sf feng-l-l-b,WJH 14-#-b-1,YTY 2-5-b-1,WJH 12-#-b,Guatemala white no2-b,waxy corn QN 126-b-b,QN 117-b-1,jinknom 2000,and yunnom 3.The sweet waxy corn N3-#-B-B and jinkuo 978 had higher nutritional quality.Among the three types of fresh corn,sweet and waxy corn had better nutritional quality.There was a significant positive correlation between water and protein,protein and fat,and a significant negative correlation between starch and water,protein and fat.5.Based on the quality and trait data of 66 fresh corn samples,using the square Euclidean distance clustering analysis method in SPSS 22.0 analysis software,66 fresh corn samples were divided into two categories and six subcategories.The clustering results were not only significantly different from the SSR clustering results,but also significantly different from the groups and genealogy of fresh corn samples,indicating that the quality trait clustering could not truly reflect the genetic relationship between the research materials. |
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