2018 ASHS Annual Conference

Chinese chestnut (Castanea mollissima Blume.), native to China, has been cultivated as an economically important fruit tree species for thousands of years. Chinese chestnut was found to display late-acting self-incompatibility (LSI), resulting in low fruit bearing percentage and yield. During the LSI process in chestnut, self pollen tubes are hampered in the ovaries instead of styles. To understand molecular character on LSI, transcriptome analysis were conducted on ovaries at four different stages after pollination. A total of 75,554 unigenes were assembled, of which 11,677 unigenes were annotated KOG database covering 26 categories. Genen Ontology (GO) enrichment analysis revealed that many genes involved in metabolic processes, cell part, binding, and catalytic activity. Among them, a number of self-incompatibility-related genes were identified including S-locus-specific glycoprotein S13 precursor, S-locus lectin protein kinase family protein, S-locus-specific glycoprotein S6, calcium-binding protein CML17, and 24 calcium-dependent protein kinase. Compared to 15 days and 30 days after pollination, we screened a total of 285 differentially expressed genes, of which there were 175 genes showed up-regulated and 110 genes down-regulated. Most of the genes participated in catalytic activity, transferase activity, hydrolase activity and nucleotide−sugar metabolic process. The results of study will help fully understand the mechanism of the chestnut LSI and provide useful information for breeding projects.