Inheritance of foliar resistance to ascochyta blight in lentil (Lens culinaris)

Inheritance of foliar resistance to ascochyta blight in lentil (Lens culinaris) was studied using four resistant (ILL 5588, ILL 5684, 'Indianhead', and 'Laird') and two susceptible inbreds (W6 3192 and 'Titore') in a glasshouse. Isolate "Rakaia" of Ascochyta lentis was used in all the experiments. F2, BC1 (backcross to the resistant parent), and BC 2 (backcross to the susceptible parent) generations of the crosses between resistant and susceptible inbreds were used to detect the inheritance models. F2 generations of the crosses between resistant and resistant inbreds and two 3-way crosses were used to test allelic relationships among resistance genes. Two dominant genes, one for resistance and one for moderate resistance, are present in ILL 5588. One dominant gene, which is allelic to the one for resistance in ILL 5588, confers the resistance in ILL 5684. One recessive gene is responsible for the resistance in cultivar 'Laird'. The resistance in 'Indianhead' is under control of two recessive genes with additive effects. Two complementary genes, one in W6 3192 and one in 'Titore', are responsible for the resistance observed in the F2 generation of the cross between these two susceptible cultivars.