Phenotypic identification of peanut germplasm for resistance to southern stem rot

Southern stem rot, caused by Sclerotium rolfsii Sacc., is a destructive soil fungal disease of peanut in China and other countries. To evaluate resistant germplasm, a total of 256 peanut accessions were investigated on their resistance to southern stem rot in 3 environments by artificial inoculation. Variance analysis indicated that disease index was significantly influenced by environment, genotype and genotype ​× ​environment interactions. Peanut accessions of var. vulgaris type exhibited higher resistance to southern stem rot. Disease index was significantly negatively correlated with linoleic acid content, while positively correlated with oleic acid content. Six resistant accessions were identified, including Hua 28, Shandongzai, ICG 6326, Quanhua 7, Quanhua 9 and Guihua 836, with their disease indexes under 40 and mortality were less than 30% in the three environments. The identified resistant accessions showed the great potential to be applied in resistant peanut breeding, and would be good genetic resources for enhancing the resistance to southern stem rot.