Evaluation of pathogenicity of Botryodiplodia theobromae and resistance to stem-end rots on the main varieties of mango

【Objective】Mango stem- end rot(Botryodiplodia theobromae)is the main fungal disease ofmango during storage. It was also found in most mango growing regions of the world. It is one of main post-harvest diseases causing production loss of mango in Hainan,which is very difficult to be controlled. Thestudy aims to clarify the pathogenicity of B. theobromae and resistance to stem-end rots on mango variet-ies,and provide the fundation for the prevention and treatment of mango stem- end rot. 【Methods】Through artificial inoculation in plastic boxes,pathogenicity of 124 stains of B. theobromae from mangofruit were tested. Resistances of 11 mango varieties to stem-end rot were evaluated by inoculation with 5strains of B. theobromae.【Results】The results showed that all stains had different pathogenicity,the highvirulent strains accounted for 28.23%,the median virulent strains accounted for 83.0%,and the low viru-lent strains accounted for 5.65%. The resistances of same variety to stem-end rot depended on the strainsinoculated. The stem-end rot resistances were graded by average disease index(DI)of 5 strains of B.theobromae. Based on the comprehensive evaluation of resistance to multiple strains,‘White Ivory'per-formed as high susceptive(HS),while other 10 materials as susceptive(S).【Conclusion】B. theobromae was considered as prevalent pathogens causing mango stem-end rot,and the high virulent strains and themedian virulent strains had wide distribution in Hainan. There was no stem-end rot resistant mango vari-ety among the 11 tested mango materials.