Study On The Adaptability Of Alfalfa Introduction And Evaluation Of Acid And Aluminum Stress In Guizhou Area

Alfalfa(Medicago sativa L.)is an important perennial leguminous forage with high protein content and good palatability.It is widely cultivated worldwide.However,alfalfa is very sensitive to acid aluminum stress,which restricts its cultivation and promotion in southern of China and restricts the development of animal husbandry in this region.In order to understand the adaptability of alfalfa in Guizhou and its resistance to acid and aluminum stress.This study takes 44 alfalfa varieties as the research object,,and used the combination of best linear unbiased estimates,principal component analysis,cluster analysis,and gene-environment interaction GGE model to conduct comprehensive analysis,9 agronomic traits of alfalfa,including plant height,stem thickness,fresh weight and dry weight,were evaluated,and alfalfa varieties with strong adaptability were selected.The selected sensitive and tolerant varieties were tested for aluminum stress,and the electrical conductivity,survival rate,root aluminum content,and organic acids content(citric acid,malic acid,lactic acid,acetic acid,tartaric acid,fumaric acid,oxalic acid and succinic acid)of the two varieties before and after aluminum stress were measured,and were used for statistical analysis to study the physiological changes of alfalfa under acid-aluminum stress and reveal the relationship between its physiological changes and acid-aluminum tolerance.The results are as follows:(1)Five alfalfa varieties with better adaptability were screened out,namely Algonquin,Xinjiang big leaf,Trifecta,Vernal,and Zhongmu No.1.(2)There are significant(P<0.05)genotypic variation in all agronomic traits of alfalfa,and the genetic diversity is rich.plant height,number of stems,fresh weight,total fresh weight and total dry weight R value are relatively high,genetic stability is relatively high,and can be used as a reference index for the breeding of alfalfa varieties.(3)The conductivity of sensitive alfalfa UC-1465 was significantly(P<0.05)higher than that of tolerant Algonquin,and the survival rate was significantly lower than that of tolerant Algonquin,and the same concentration The aluminum content of resistant type is significantly lower than that of sensitive type UC-1465.(4)Citric acid,malic acid,acetic acid,tartaric acid,fumaric acid,oxalic acid and succinic acid of the two alfalfa varieties increased significantly(P<0.05)under aluminum stress.Oxalic acid is the most secreted organic acid from the roots of alfalfa,followed by tartaric acid,succinic acid and citric acid.The content of tolerant organic acids is higher than that of sensitive ones,and malic acid reaches a significant level.