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

Table 3 Comparison of mycelial growth, conidiation, and virulence between the tebuconazole-sensitive and tebuconazole-resistant isolates of Colletotrichum siamense

Isolates	Phenotype	Genotype	Colony diameter (mm)^a	Conidiation (× 10⁵ spores/mL)^b	Lesion size (mm)^c
Zz14	Field/S	–	83.00 ± 0.85a	9.25 ± 0.56a	11.15 ± 0.98a
Zz17	Field/S	–	82.66 ± 0.77a	9.21 ± 0.51a	10.98 ± 0.64a
Zz9	Field/HR	I	82.67 ± 1.15a	8.13 ± 0.21b	6.73 ± 0.33b
Zz10	Field/HR	I	82.33 ± 1.14a	8.21 ± 0.22b	7.21 ± 0.45b
Zz5	Field/HR	II	74.01 ± 1.34b	3.59 ± 0.19f	6.59 ± 0.28b
Zz20	Field/HR	II	73.160 ± 0.94bc	3.54 ± 0.17f	6.85 ± 0.37b
Zz11	Field/HR	III	69.50 ± 1.21d	6.14 ± 0.33d	4.84 ± 0.15c
Zz22	Field/HR	III	70.00 ± 0.79d	6.19 ± 0.46d	4.62 ± 0.26c
Zz12	Field/R	IV	72.50 ± 0.53bc	7.23 ± 0.17c	3.51 ± 0.26d
Zz18	Field/R	IV	72.51 ± 0.80bc	7.28 ± 0.21c	3.14 ± 0.24de
Zz3	Field/R	V	73.33 ± 0.49bc	4.89 ± 0.42e	2.63 ± 0.22f
Zz15	Field/R	V	72.00 ± 0.75c	4.82 ± 0.19e	2.87 ± 0.31ef

Values 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. ^aThe isolates were grown on PDA medium, and colony diameter of each isolate was measured after 5 days of incubation at 25 °C. ^bThe sensitive and resistant isolates were incubated in PDB medium for 5 days at 25 °C, and conidia produced by each isolate were collected and determined using a hemocytometer. ^cMycelial plugs of each isolate were inoculated on wounded chili fruits, and lesion sizes were measured after 7 days of incubation. Each isolate was inoculated on 15 chili fruits