Studies on carbendazim-resistance of Colletotrichum gloeosporioides on mango fruit.
Zhan RuLin, Li Wei, Zheng FuCong
Author Affiliation: Southern Subtropical Crops Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang 524091, China.
Acta Phytophylacica Sinica 32 : 71-76
Abstract : The carbendazim resistance of C. gloeosporioides [Glomerella cingulata] infecting mango was tested in vitro. The minimum inhibitory concentration of sensitive isolates were 0.110 µg/ml. Resistant isolates were able to grow well even in carbendazim at 500 µg/ml. Carbendazim resistance was stably inherited after continuous transfer for 10 generations on carbendazim-free PDA medium. The biological characters of resistant and sensitive isolates were tested and compared. Correlation analysis of MIC to the number of conidia produced and pathogenicity was conducted. Results showed that these factors did not correlate with carbendazim resistance. Resistant isolates showed positive cross-resistance to thiophanate-methyl, benomyl and thiabendazole, and sensitivity to diethofencarb and prochloraz. The resistant and sensitive isolates were inoculated on mango fruits soaked in carbendazim solution in vitro. Fruits treated with fungicide and then inoculated with resistant isolates showed disease symptoms as severe as the control, while those inoculated with sensitive isolates did not show symptoms.