TABLE 6.

Dominance of resistance to Cry1Ac in the Melaka population of P. xylostella as a function of the concentration of Cry1Ac

Concn (μg ml−1)	Population	Mortalitya (%)	Fitnessb	hc
0.002	Cry1Ac-SEL	0	1
	ROTH	23	0.77
	F1d	13	0.87	0.43
	F1e	3	0.97	0.87
0.02	Cry1Ac-SEL	0	1
	ROTH	100	0
	F1d	43	0.57	0.57
	F1e	38	0.62	0.62
0.2	Cry1Ac-SEL	0	1
	ROTH	100	0
	F1d	80	0.20	0.20
	F1e	60	0.40	0.40
1.0	Cry1Ac-SEL	0	1
	ROTH	100	0
	F1d	83	0.17	0.17
	F1e	85	0.17	0.17
1.5	Cry1Ac-SEL	0	1
	ROTH	100	0
	F1d	87	0.13	0.13
	F1e	85	0.15	0.13

^an = 40 (39 for ROTH at 0.002 μg ml⁻¹). 

^bFitness is the survival rate of the larvae divided by the survival rate of Cry1Ac-SEL larvae (survival rate is estimated as 100 − percent mortality). 

^cDominance (h) can vary from 0 (completely recessive resistance) to 1 (completely dominant resistance); h = (w₁₂ − w₂₂)/(w₁₁ − w₂₂), where w₁₁, w₁₂, and w₂₂ are the fitness values for resistant homozygotes, heterozygotes, and susceptible homozygotes, respectively. 

^dF₁ hybrid progeny of mass crosses between 40 females of ROTH and 40 males of Cry1Ac-SEL. 

^eF₁ hybrid progeny of mass crosses between 40 females of Cry1Ac-SEL and 40 males of ROTH.