Identification Of Cold Hardiness Related Phenotypes And Analysis Of Characteristic Metabolites In Eight Potato Genotypes

The cultivated potato is generally not tolerant to frost,which hinders the development of potato industry to a certain extent.Therefore,it is of great significance to analyze the reasons for the differences in cold resistance of different potato materials.In this study,physiological phenotype differences,metabolites and metabolic pathways of eight different genotypes of potato materials were analyzed under normal temperature conditions and cold acclimation treatment for 1 day and 7 days,the main results are as follows:1.In this study,eight potato materials of different genotypes were treated with cold acclimation for 0,1 and 7 days,and the low temperature resistance of these eight materials under three treatments was identified by electrolyte leakage method and frost experiment.The results show that LT₅₀values of E3,RH,M6,SVA-S15 and SVA-S16are higher than-3.0℃at normal temperature,which indicates that they are low-temperature sensitive materials.LT₅₀values of ACL-27,CMM60-2 and MLM266-2are<-3.0℃,which belong to cold resistant materials.After 1 day of cold acclimation,the strongest acclimation capacity of MLM266-2 was 1.922℃,which was much stronger than other materials.After 7 days of cold acclimation,the acclimation capacity of MLM266-2 and CMM60-2 was 3.509℃and 1.894℃,respectively,which were significantly higher than other materials and belongs to the strong acclimation-capacity material.2.The Fv/Fm value of chlorophyll fluorescence could reflect the damage degree of plants to a certain extent.In this experiment,the chlorophyll fluorescence of 8 potato materials under three treatment conditions before and after frost treatment was measured.The results showed that there was a significant positive linear correlation between the Fv/Fm value and the absolute value of LT₅₀of eight potato materials after frost treatment,indicating that chlorophyll fluorescence Fv/Fm values can reflect the degree of plant stress to a certain extent and can be used as an indicator for identifying potato cold resistance.3.Based on LC-MS,a wide range of untargeted metabolic analyses were performed on eight potato materials at normal temperature and after 1 and 7 days of cold acclimation.The results showed that the constitute contents of some metabolites in the eight potato materials were directly related to the direct cold resistance of potato,including lipid,carboxylic acid,carbohydrate,flavonoid and terpenoid metabolites.Substances related to cold acclimation ability of potato after 1 day of cold acclimation included coumarins,flavonoids,benzoquinones and lipids.Lipid,carboxylic acid,carbohydrate,amino acid and terpene metabolites were related to cold acclimation capacity of potato after cold acclimation for 7 days.These differential metabolites can be used as biomarkers to evaluate the cold resistance of potato.4.KEGG enrichment analysis of different metabolites of 8 potato materials after cold acclimation for 7 days showed that"Biosynthesis of unsaturated fatty acids","metabolism of linoleic acid","biosynthesis of valine,leucine and isoleucine"were specifically enriched in the materials with strong cold acclimation resistance.These metabolic pathways play an important role in the formation of cold acclimation and cold resistance of potato.