Analysis And Evaluation Of Main Traits Of 50 Sweet Corn Hybrids From Domestic And Abroad

Sweet corn breeding research in China started in the 1960 s.Genetic breeding research of sweet corn has had a rapid development since entering the 21 st century,achieving delightful achievements.However,compared with the advanced level reached by the other countries,we are lacking in the resources of sweet corn germplasm and our basic research is relatively weaker,which has a restriction on the development of breeding industry.To breed sweet corn varieties with high yield,high quality and good resistance have become a major problem for breeders.In order to explore the specific differences of domestic and foreign sweet corn varieties and provide basic reference for sweet corn breeding research in China,this experiment tries to have an analysis on 50 domestic and foreign sweet corn hybrids(varieties)for their three kinds of main traits such as agronomic traits,grain traits and quality traits.The results are as follows:1.In terms of agronomic traits,sweet corn varieties in China are superior to foreign varieties in the plant height,ear height,stem diameter,number of stem node,number of leaves above the ear and harvest time.These six indexes respectively are 29.71% 、88.85%、19.50%、30.00%、20.00%、6.62% higher than the foreign varieties,reaching a significant level.The average harvest time of domestic varieties is 79 days,while that of foreign varieties is 74 days,which shows relatively late maturity.The results of cluster analysis also show that the domestic and foreign sweet corn varieties can be clearly divided into different groups,indicating that there are significant differences in agronomic traits of sweet maize varieties at home and abroad.2.In terms of ear traits,the weight of fresh bract,net weight of each ear,the length of the ear and the bald tip,grain number per row and ear diameter of sweet corn varieties in China are respectively 26.67%,22.73%,5.24%,126%,17.27%,7.90% higher than those of foreign varieties(p < 0.05).However,the number of rows per panicle is significantly lower than that of foreign varieties(p < 0.05),with an average of less than2 rows.Yet there is no significant difference in 100-grain weight and axial diameter between the two groups(p > 0.05).The results of cluster analysis show that the varieties of sweet corn at home and abroad can be clearly divided into different groups,indicating that there is a significant difference between them.3.In terms of quality traits,sucrose content and taste score of domestic varieties are significantly lower than those of foreign varieties(p < 0.05),but there is no significant difference in reducing sugar content between the two varieties(p > 0.05).However,the thickness of the skin of sweet corn varieties in China is significantly thicker than that of foreign varieties(24.00% higher)(p < 0.05),indicating that there is still a gap between the quality of domestic sweet corn and abroad.The results of cluster analysis show that there are four kinds of sweet corn varieties at home and abroad,and the quality of some sweet corn varieties in China has been greatly improved,and therefore has been classified into foreign varieties.4.According to the correlation analysis of the main characters,all agronomic traits have positive correlation and reaches to a very significant level.The most significant correlation is between the plant height and the height of ears,and the correlation coefficient reaches to 0.92.The minimum correlation is between the spike height and leaf blade number,whose coefficient reaches to 0.62.In terms of quality traits,the correlation between single ear yield and row grain number is the most significant,and the correlation coefficient is 0.70.The correlation coefficient between single ear yield and stem diameter is 0.68.In terms of quality traits,the taste of sweet corn is correlated with sucrose content and the thickness of the skin,both reach to extremely significant level.The correlation coefficient between sucrose content and the taste of sweet corn is 0.59,and that between the skin thickness and the taste is minus 0.58.In addition,the early or late harvest of the harvest also affects the taste of sweet corn,and they are negatively correlated and reached to a significant level.