| Eggplant(Solanum melongena L.)is one of the important vegetable crops in China.With the continuous growth of eggplant planting area and multiple cropping index,disease has become the main factor affecting the yield and quality of eggplant.Sclerotinia rot is one of the main diseases of eggplant.The pathogen has a wide host range and causes great economic losses to the vegetable industry in China annually.It is difficult to prevent and control the occurrence of Sclerotinia rot effectively using drugs.Therefore,identifying eggplant germplasm which is resistant to Sclerotinia rot and excavating the key genes regulating the resistance are important to breeding for the Sclerotinia rot resistance in eggplant.In this study,based on the collection and extraction of Sclerotinia rot pathogen from infected eggplant,the eggplant mutant dwf,wild type ’14-345’,their hybrid F1,and their F2 population were used in this experiment.The resistant germplasms to Sclerotinia rot in eggplant were screened by disk inoculation at flowering stage and then the genetic rule of the resistance was analyzed.Extremely resistant and susceptible individuals were selected from the F2 population to construct a bulk,and Mutmap method was used to screen the resistant genes.At the same time,the genes related to Sclerotinia rot in eggplant were further identified by transcriptome sequencing analysis.The main results are as follows:1.The Sclerotinia rot pathogens collected from the infected eggplants which grew in the areas mainly producing eggplants.Through observing the morphological characteristics,measuring the pathogenicity to eggplants and amplifying the conserved region of the pathogen sequence,it was confirmed that the pathogen collected from the infected eggplants was Sclerotinia sclerotiorum.2.It was identified the dwf showed moderate resistance belonging to resistant level by inoculation identification using the extracted pathogen,the F1 and wild-type ’14-345’showed high sensitivity belonging to susceptible level.The number of susceptible and resistant plants in F2 population was separately 98 and 85.Chi-square test analysis showed that the separation ratio of susceptible and resistant plants was conformed to 9:7(X2=0.541<X20.05=3.84),indicating that the resistance to Sclerotinia sclerotiorum in dwf was controlled by two recessive genes.3.The susceptible pool(30 plants)and the resistant pool(30 plants)were constructed based on the inoculation identification results of F2 population.The candidate regions significantly associated with Sclerotinia rot resistance were located by MutMap method,and five candidate genes related to sclerotinia resistance were screened combined with gene function annotation.4.Transcriptome analysis of stem materials infected with Sclerotinia sclerotiorum for 0 h,6 h and 24 h from the dwf mutant and wild-type ’14-345’ was processed and totally1286 differentially expressed genes were screened.GO enrichment analysis showed that differentially expressed genes were mainly enriched in the regulation of biological processes,cell processes and membrane structure.KEGG enrichment analysis showed that the differentially expressed genes were mainly concentrated in the plant-pathogen interaction,plant hormone signal transduction,phenylpropanoid biosynthesis and other related disease resistance pathways.5.Jointly analyzing the candidate genes obtained by MutMap and transcriptome sequencing,two candidate genes related Sclerotinia sclerotiorum resistance were screened,one was annotated to calmodulin-binding transcription activator and the other one was annotated to LRR repeat receptor protein kinase rich in leucine. |
PDF Full Text Request