TABLE 2.

Direct test of monogenic inheritance for resistance to Cry1Ab protoxin by comparing expected and observed mortality of the backcross F1 and ROTH populations of P. xylostella

Concn (μg ml−1)No. of larvae testedObserved mortality (%)Expected mortalitya (%)χ2 (df = 1)bP
0.2130502114.87<0.001
0.51345821125.69<0.001
11358026210.29<0.001
21338931207.16<0.001
41289642153.76<0.001
  • a Expected number of larvae dead at given dose = 0.5 (number of F1 larvae that die + number of selected larvae that die).

  • b df = degrees of freedom.