Salt Tolerance Screening And Evaluation Of 14 Alfalfa Hybrid Combinations

In order to screen salt-tolerant crops suitable for salinized land cultivation,the application of hybrid seed production of alfalfa at the same time can effectively improve the yield,resistance and quality of alfalfa,which is of great significance for the development of alfalfa industry.In this study,male sterile line MS-GN was used as the female parent,and 14 hybrid combinations with 14 elite alfalfa cross combinations were used as the parent to study the CAT activity and POD activity of seedlings under different salt stress.The determination of SOD activity,SOD activity,MDA content,soluble sugar content,and soluble protein content were combined with membership function method to comprehensively evaluate the salt resistance ability of F1 generation of 14 alfalfa hybrid combinations.In addition,the high yield and quality of alfalfa were determined by measuring the biological characteristics such as yield and nutritional quality of F1 hybrids in each crossbreeding group,which provided excellent selection and data basis for the breeding of elite alfalfa hybrids.The main findings are as follows:1.In indoor pot experiment,different combinations had different responses to different concentrations of salt stress,soluble protein,soluble sugar,CAT,POD,SOD were positively correlated with tolerance,while MDA was negatively correlated with tolerance.The salt tolerance is ranked from large to small as follows: combination 2>combination 3>combination 12>combination11>combination14>combination 5>combination 1>combination 6> Combination 9>combination 13>combination 4>combination 7>combination 8>combination 10.2.Through comprehensive analysis of the yield traits and nutritional quality traits of 14 alfalfa hybrid F1 generations,it was found that there was a significant difference in the yield and quality of alfalfa F1 generation(P<0.05).The number of branches per plant was the highest in the cross combinations of 6 and the content of nitrogen-free extracts was also the highest.The 7 plant height and fresh grass yield were the highest in the cross combinations,and the hay yield and leaf-stem ratio were the highest in the cross combinations of 10.The percentage of crude fat content in the combination 9 is the highest,the crude protein content in the hybrid combination 13 is the highest,and the percentage of crude fat content also ranks in the front.Hybridization between MS-GN and 55V48 was prominent in plant height and yield of fresh grasses;MS-GN and Crown,BR4010 and Gannong-3 were good for improving forage quality;hybrids with alfalfa variety 54V09 were dominant in grass yield.The potential for a combination of high yields can be obtained.Combined with the grey correlation analysis,the number of branches per plant,hay yield,crude protein,and crude fat had the greatest influence on the comprehensive production performance of alfalfa,and the combination of Crown and Victorian MS-GN had the best overall production performance.Followed by BR4010 × MS-GN,MF4020 × MS-GN;WL440HQ × MS-GN comprehensive production performance is relatively poor.3.Combined with the two parts of the experiment,we can screen out the BR4010,Victorian as the male and the male sterile MS-GN hybrid combinations are superior in salt tolerance and yield quality.