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

Table 4 Sensitivities of Colletotrichum siamense isolates to tebuconazole, difenoconazole, prochloraz, and propiconazole

Isolates	Phe	Gen	Tebuconazole		Difenoconazole		Prochloraz		Propiconazole
Isolates	Phe	Gen	EC₅₀ (mg/L)^a	RF^b	EC₅₀ (mg/L)	RF	EC₅₀ (mg/L)	RF	EC₅₀ (mg/L)	RF
Zz14	S	–	0.039 ± 0.0036e	–	0.018 ± 0.0013e	–	0.026 ± 0.0025e	–	0.065 ± 0.0016e	–
Zz17	S	–	0.042 ± 0.0012e	–	0.015 ± 0.0024e	–	0.027 ± 0.0012e	–	0.063 ± 0.0023e	–
Zz9	HR	I	0.61 ± 0.056d	15.06	0.14 ± 0.036d	8.48	0.033 ± 0.0041d	1.24	0.22 ± 0.016d	3.43
Zz10	HR	I	0.65 ± 0.023d	16.05	0.16 ± 0.013d	9.69	0.033 ± 0.0053d	1.24	0.23 ± 0.014d	3.59
Zz5	HR	II	1.73 ± 0.27a	43.21	0.92 ± 0.031a	55.75	0.084 ± 0.0015a	3.16	0.78 ± 0.013a	12.18
Zz20	HR	II	1.91 ± 0.17a	47.16	0.98 ± 0.014a	59.39	0.085 ± 0.0016a	3.21	0.75 ± 0.027a	11.71
Zz11	HR	III	1.11 ± 0.24b	27.4	0.39 ± 0.061b	23.63	0.068 ± 0.0038b	2.56	0.45 ± 0.019b	7.03
Zz22	HR	III	1.15 ± 0.22b	28.39	0.41 ± 0.052b	24.85	0.071 ± 0.0013b	2.67	0.49 ± 0.036b	7.65
Zz12	HR	IV	1.12 ± 0.14b	27.65	0.47 ± 0.022b	28.48	0.043 ± 0.0020c	1.62	0.28 ± 0.032c	4.37
Zz18	HR	IV	1.14 ± 0.21b	28.15	0.44 ± 0.034b	26.67	0.045 ± 0.0014c	1.69	0.31 ± 0.015c	4.84
Zz3	HR	V	0.71 ± 0.054 cd	17.53	0.28 ± 0.037c	16.96	0.034 ± 0.0064d	1.28	0.29 ± 0.064c	4.53
Zz15	HR	V	0.74 ± 0.061c	18.27	0.31 ± 0.012c	18.78	0.037 ± 0.0031d	1.39	0.28 ± 0.051c	4.37

^aValues are the means ± standard deviations from three replicate experiments. Different letters indicate significant differences according to the Fisher’s LSD test at P = 0.05. ^bRF (resistance factor) = EC₅₀ value (resistant isolate)/EC₅₀ value (sensitive isolate)