TABLE 1.

Virulence of A. tumefaciens strains on various plants

Plant and organ	Virulencef
	C58 (wild type)b	A205 (AttR mutant)g
B. daigremontiana leavesa	100 ± 5	0 (80)
Carrot root disksc	100 ± 10	0 (25)
Tomato stemsa	100 ± 5	0 (40)
Bean stemsa	75 ± 15	0 (10)
Pea stemsa	75 ± 20	0 (15)
Alfalfa stemsc	46 ± 10	0 (35)
Bean leavesd	100 ± 10	0 (16)
Bean root diskse	75 ± 20	0 (10)
Pea root diskse	40 ± 15	0 (10)

^aTumors were scored 6 weeks after inoculation. 

^bMean ± standard deviation of a minimum of three experiments. 

^cTumors were scored 8 weeks after inoculation. Each disk was scored as positive or negative. The average carrot root disk inoculated with C58 had about 20 tumors. 

^dTumors were scored 1 week after inoculation. Each leaf was scored as positive or negative. The average leaf inoculated with C58 had about five tumors. 

^eTumors were scored 4 weeks after inoculation. Each root disk was scored as positive or negative. The average bean or pea root disk inoculated with C58 had about three tumors. 

^fPercentage of inoculated sites developing tumors after inoculation with bacterial strain. 

^gNumbers in parentheses represent the number of plants scored. No tumors were ever detected in any of these inoculations.