Sterol demethylation inhibitor fungicide resistance in Colletotrichum siamense from chili is caused by mutations in CYP51A and CYP51B

Table 1 Sensitivities of Colletotrichum isolates from chili to tebuconazole

Isolates	Phenotype^a	EC₅₀ (mg/L)^b	MIC (mg/L)^c	RF for EC₅₀^d
Zz14	Field/S	0.039 ± 0.0036e	2	–
Zz17	Field/S	0.042 ± 0.0012e	2	–
Zz1	Field/HR	1.09 ± 0.17b	60	26.91
Zz2	Field/HR	1.13 ± 0.15b	65	27.90
Zz3	Field/HR	0.68 ± 0.013 cd	55	16.79
Zz4	Field/HR	0.72 ± 0.034c	55	17.77
Zz5	Field/HR	1.73 ± 0.27a	75	42.71
Zz6	Field/HR	1.94 ± 0.11a	80	47.90
Zz7	Field/HR	1.82 ± 0.13a	80	44.93
Zz8	Field/HR	1.75 ± 0.25a	75	43.21
Zz9	Field/HR	0.61 ± 0.056d	55	15.06
Zz10	Field/HR	0.65 ± 0.023d	55	16.05
Zz11	Field/HR	1.11 ± 0.24b	65	27.41
Zz12	Field/HR	1.12 ± 0.14b	65	27.65
Zz15	Field/HR	0.71 ± 0.054 cd	55	15.06
Zz16	Field/HR	0.74 ± 0.061c	55	18.27
Zz18	Field/HR	1.14 ± 0.21b	65	28.15
Zz19	Field/HR	1.91 ± 0.17a	80	47.16
Zz20	Field/HR	1.78 ± 0.29a	75	43.95
Zz21	Field/HR	0.69 ± 0.038 cd	55	17.04
Zz22	Field/HR	1.15 ± 0.22b	65	28.39
Zz23	Field/HR	1.08 ± 0.21b	60	29.13

^aS sensitive, HR high-resistant. ^bValues are the means ± standard deviations. Different letters indicate significant differences according to the Fisher’s LSD test at P = 0.05. ^cMIC minimal inhibitory concentration. ^dRF (resistance factor) = EC₅₀ value (resistant isolate)/EC₅₀ value (sensitive isolate)