| The Grassland Institute of the Chinese Academy of Agricultural Sciences collected 17 alfalfa varieties from home and abroad in May 2017 and introduced them in Menyuan County.After the winter,only 3 alfalfa varieties successfully survived the winter in 2018.In this study,three alfalfa varieties(Medicago sativa)successfully overwintered at two test sites in Honggou Village and Hougou Village,Menyuan County were used as test materials to determine the physiological and biochemical indicators in different periods and production in different years from 2018 to 2020.Performance,explore the cold resistance physiology of 3 alfalfa varieties,and provide a theoretical basis for alfalfa breeding in alpine regions.the result shows:1.In 2018 and 2019,Honggou M.sativa Chiza No.1 has the highest plant height and hay yield,M.sativa Gongnong No.1 has the highest fresh grass production,and M.sativa Zhongmeng No.1 has the highest plant height in 2020,and M.sativa Gongnong No.1 fresh grass.The yield is the highest,the yield of M.sativa Chiza No.1 hay is the highest,the plant height of M.sativa Zhongmeng No.1 in Hougou 2018 is the highest,and the yield of M.sativa Gongnong No.1 fresh grass is,the highest hay yield,the highest plant height of M.sativa Gongnong No.1 in 2019 and 2020,and the highest fresh grass yield of M.sativa Zhongmeng No.1 in 2019.The hay yield is the highest.In 2020,M.sativa Gongnong No.1 fresh grass yield is the highest,and M.sativa Zhongmeng No.1 hay yield is the highest.M.sativa Zhongmeng No.1 has the highest plant height and hay yield,and M.sativa Gongnong No.1 has the highest fresh grass yield.The higher the plant height and yield,the stronger the cold resistance of the variety.2.In Honggou,M.sativa Zhongmeng No.1 has the longest tap root,the largest area,surface area,volume,and average root diameter.M.sativa Gongnong No.1 has the longest lateral root,the most number of lateral roots,and the largest dry weight of the main root and lateral root.In Hougou,M.sativa Zhongmeng No.1 has the longest tap root,M.sativa Gongnong No.1 has the largest volume,M.sativa Chiza No.1 lateral root has longest length,and the number of lateral roots,main root dry weight,and lateral root dry weight are the largest.The cold resistance of cultivar is positively correlated with root morphology.Honggou’s M.sativa Zhongmeng No.1has the strongest cold resistance,while Hougou’s M.sativa Chiza No.1 is slightly more cold-resistant than M.sativa Zhongmeng No.1.3.With the gradual decrease in temperature during the overwintering period from October to January,the content of soluble sugar,soluble protein,free proline,and peroxidase The content(activity)of sucrose,superoxide dismutase,catalase,sucrose,glucose,fructose,and stachyose showed an upward trend.During the lowest temperature period,alfalfa roots accumulate a large amount of soluble sugars and other substances to resist the cold and obtain Cold resistance ability,the temperature rises from January to August,and its content(activity)gradually decreases,which is negatively correlated with temperature and positively correlated with cold resistance;during the lowest temperature period in January,malondialdehyde,starch,total sugar,The content of reducing sugar and raffinose is the lowest,and then the content increases with the increase of temperature,which is positively correlated with temperature and negatively correlated with cold resistance.4.Using fuzzy function membership function method to analyze the cold resistance of the three alfalfa varieties successfully overwintering in Menyuan County,it was found that M.sativa Zhongmeng No.1 had the best cold resistance and M.sativa Gongnong No.1 had the weakest cold resistance.Analyzing the production performance and root morphology of the three alfalfa varieties with grey correlation degree,it was found that M.sativa Zhongmeng No.1 had the best comprehensive characters. |
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