IDENTIFICATION AND GENETIC-CHARACTERIZATION OF DIFFERENT RESISTANCE SOURCES TO ASCOCHYTA BLIGHT WITHIN THE GENUS LENS

Genetic regulation of host resistance in lentil to ascochyta blight wa s found to be controlled by two complementary dominant gene pairs in w ild species of Lens ervoides and Lens odemensis. Both genes must be pr esent in the dominant form, whether homozygous or heterozygous, for co mplete resistance. When one pair of genes is present in homozygous rec essive state, they mask the effect of the other dominant gene pair and ultimately makes the lentil plant susceptible to the pathogen, a case of duplicate recessive gene interaction. The results also suggested t hat in Lens culinaris ssp. orientalis, ascochyta blight resistance was controlled by a single dominant gene pair. The possible utilization o f wild Lens species to improve the genetic resistance of cultivated le ntil to ascochyta blight is reported and it is suggested that interspe cific hybrids should be included in lentil breeding programmes aiming at ascochyta blight resistance.