Resistance to Multiple Tuber Diseases Expressed in Somaclonal Variants of the Potato Cultivar Russet Burbank

Table 5

Stem canker severity evaluation of selected potato cv. Russet Burbank variants in glasshouse (GH1—2010; GH2 and GH3—2011) trials. Rhizoctonia solani AG3 isolates R299, R422, and TAS1 were tested separately in each trial.

Variants	Mean stem canker^a—GH1			Mean stem canker—GH2			Mean stem canker—GH3
	R299 ^b	R422	TAS1	R299	R422	TAS1	R299	R422	TAS1
A380	0.63^a	0.06	0.06	0.67	0.67	0.67	0.00	0.33	0.33
A168a	0.94^ab	0.63	0.44	—	—	—	—	—	—
TC-RB8	0.31^a	0.38	0.25	1.33	0.67	0.00	0.67	1.00	0.00
A362	1.63^b	0.94	0.56	—	—	—	—	—	—
Russet Burbank (parent)	0.88^ab	0.63	0.63	0.33	0.50	0.00	0.67	0.67	0.33
𝑃	0.02	0.40	0.149	0.28	0.91	0.11	0.31	0.25	0.69
LSD (0.05)	0.80	ns	ns	ns	ns	ns	ns	ns	ns

—: lines not tested within the specified trial.
^aStem canker disease score—0: no disease, 1: <10% of stem area covered with lesions, 2: 10–25% of stem area covered with lesions, 3: 26–50% of stem area covered with lesions, and 4: stem girdled with lesions.
^bMeans followed by the same letter within the same column are not significantly different at 𝑃=0.05 using Fisher’s LSD test; ns: nonsignificant.