Detection of -tubulin gene from benomyl sensitive isolates of Colletotrichum gloeosporioides causing anthracnose disease in mango

Abstract

Twenty six isolates of Colletotrichum gloeosporioides from anthracnose infected mango fruits were isolated from different places of Tamil Nadu, India and these isolates were identified as C. gloeosporioides by Internal transcribed spacer (ITS) and species specific (CgInt) primers. The sensitivity of C. gloeosporioides isolates to benomyl fungicide were evaluated at five different concentrations viz., 0.5, 1, 2, 5, 10 mg/l through poisoned food technique and were expressed very less to highly sensitiveness to the fungicide. All the twenty six isolates were able to grow at the lowest concentration of 0.5 mg/l benomyl amended medium and the average mycelial growth was 70.70 mm at even days after inoculation. At the highest concentration of 10 mg/l benomyl, only two isolates viz., MCG 7 and 16 were able to grow with the mycelial diameter of 12.00 and 18.00 mm, respectively and 100% inhibition was found in the remaining isolates. In addition, benzimidazole sensitive and resistance β-tubulin gene sequences of TUB 1 and TUB2 were amplified from the benomyl sensitive isolates of C. gloeosporioides. The results indicated the differential resistance or sensitivity to benomyl fungicide against C. gloeosporioides and thereby allowed to identify the variability and diversity of the isolates on regional basis.