Characterization and pathogenicity of Rhizoctonia spp. from field crops in Canada

Figures & data

Table 1. Province, crop, number of fields surveyed, number of fields with Rhizoctonia spp., and anastomosis groups (AG) of recovered R. solani isolates.

			No. fields with Rhizoctonia		R. solani
Province	Crop	No. fields Surveyed	R. solani	Binucleate	AGs
Alberta	Barley	4	0	0	–
	Canola	13	6	0	2-1
	Pea	1	1	0	2-1
	Wheat	10	6	2	2-1, 4, 5, 9
Saskatchewan	Barley	1	0	0	–
	Canola	9	8	0	2-1, 9, 11
	Pea	1	1	0	2-1
	Wheat	3	2	0	2-1, 9
Manitoba	Canola	6	4	0	2-1
	Soybean	1	0	0	–
	Wheat	12	7	3	2-1, 4, 5
Ontario	Corn	3	0	2	–
	Soybean	80	11	20	2-2, 5
	Winter Wheat	12	0	4	–
	Bean	4	3	1	2-2
Quebec	Soybean	10	3	3	2-2
Total		170	52	35

Table 2. Number of isolates of Rhizoctonia spp. recovered and source of isolates listed by anastomosis group (AG).

		Source of Isolate
AG	Number of Isolates	Roots (%)	Crown (%)
2-1	94	18	82
2-2	47	38	62
4	15	7	93
5	18	28	72
9	3	0	100
11	1	0	100
Unknown	13	31	69
Binucleate	52	15	85
Total	243	22	78

Table 3. Isolates of Rhizoctonia spp. pathogenic on hosts in growth room pathogenicity assay listed by anastomosis group.

AG	No. of isolates	Isolates pathogenic^a on host plant (%)
		Canola	Corn	Lentil	Pea	Soybean	Wheat
2-1	94	100	–	56	36	28	29
2-2	47	100	83	–	91	98	100
4	15	100	–	100	100	93	93
5	18	94	100^b	93^b	78	72	89
9	3	67	–	0	0	0	67
11	1	100	–	100	100	100	100
Unknown	13	92	73^c	50^c	85	85	92
Binucleate	52	25	18^d	13^d	13	23	21
Total	243	83	55	62	51	51	53

^a Significantly greater disease severity compared with non-infested control.

^b Three isolates from central Canada were tested on corn, 15 isolates from western Canada were tested on lentil.

^c Eleven isolates from central Canada were tested on corn, two isolates from western Canada were tested on lentil.

^d Forty-four isolates from central Canada were tested on corn, eight isolates from western Canada were tested on lentil.