Table 2.

Resistance to four Bt toxins produced by exposure of a hybrid isofemale line (QL4) to either toxin Cry1Ab or Cry1Ac

Source	Generation	Toxin	10 mg/liter		100 mg/liter
			n	Mortality,* %	n	Mortality,* %
QL4	F1†	Cry1Ab	21	62	17	65
		Cry1Ac	19	63	19	37
Others‡	F1	Cry1Ab	100	100	96	100
		Cry1Ac	99	100	96	100
QL4	F2§	Cry1Ab	100	4	100	0
		Cry1Ac	100	0	100	4
QL4	F4	Cry1Aa	100	0	96	0
QL4	F8	Cry1Ab	40	0	40	0
		Cry1Ac	40	0	41	0
QL4	F10	Cry1F¶	50	2	50	0

^*Mortality after 5 days was adjusted for control mortality. 

^†F₁ progeny from family QL4 were produced by one NO-QA female and one LAB-P male; pooled mortality of F₁ (56%) was not significantly different from 50% (χ2 = 1.32, df = 1, P > 0.2). 

^‡Five other F₁ families from single-pair crosses of NO-QA × LAB-P were tested simultaneously with QL4. 

^§Thirty-one F₁ survivors of exposure to Cry1Ab or CryAc were pooled and mated among themselves to produce F₂. 

^¶Concentrations for Cry1F were 1 and 10 ml of formulated Cry1F per liter.