Mapping And Cloning Of Cold Resistance Genes In The Field Of S. Commersonii

The potato is the fourth most economically important food crop,vegetatively cultivated in 160 countries worldwide.The rapid increase in the worldwide population soar-rocket the food shortage.Moreover,climate change caused by global warming has led to a significant reduction in the production of frost-intolerant potatoes;leading to food security issues.Therefore,diving into the frost resistance traits of potato materials has particular importance for their growth and development management,which significantly reduce yield losses.Here,through QTL mapping the frost-resistant S.commersonii and susceptible S.verrucosum materials were used as parents to map the frost-resistance genes in naturally frost weather using a BC₁ segregating population.The main results were as follows:1.Phenotyping:The natural frost phenotype identification method was used to assess the phenotypes of 286 BC₁ individuals in 2022 and 2023.The phenotypic distribution in2022 was between 0-2 and uniformly in 2023.However,under the artificial cooling method,the phenotypic distribution was more ranging between 3 and 4.Correlation analysis showed a significant correlation between the population materials phenotypes from 2017 to 2023;except for 2022 and artificial collling method.2.Mapping of frost genes on Chromosome 11:Twenty homozygous resistant and susceptible plants were selected,and an extreme pool was constructed for sequencing.Seven algorithms were used to analyze frost-resistance loci.In addition to the 2 QTL regions previously identified on Chromosome 2,two novel QTL regions were identified on Chromosome 11.Subsequently,120 pairs of Indel markers were developed within 33 Mb-45 Mb,and t-tests were performed with phenotypic data to screen out 35 pairs of markers with high linkage to the phenotype,and a linkage map was constructed,narrowing the candidate interval to within 462 kb.Expression analysis of the parents and the resistant or susceptible progeny after low temperature treatment was performed,and two candidate genes,Solcom.CMM.11G031266.2 and Solcom.CMM.11G031271.1,were initially identified in the interval.3.Analysis of candidate genes on chromosome 2:Based on BSA data and the 889 kb interval previously located on chromosome 2,Soltu.DM.02G027730 was preliminarily identified as a frost-resistant candidate gene.Analyzing CDS and amino acid sequences indicate that the gene underwent synonymous mutations in resistant and susceptible materials.Moreover,the difference in promoter activity between the resistant and susceptible materials were predicted to led to variation in frost resistance.Subsequently,primers were designed for the CDS region of Soltu.DM.02G027730,and an overexpression vector was constructed.The gene was transformed into susceptible material E3 based agrobacterium-mediated genetic transformation for further investigation.