Inheritance of resistance to Ascochyta blight in lentil

Non-Peer ReviewedLentil (Lens culinaris Medik.) is a major grain legume (pulse) crop in North America. Canada is the second largest lentil producer and the largest exporter in the world (Slinkard, 1996). Ascochyta blight, caused by Ascochyta fabae Speg. f.sp. lentis Gossen, is a serious disease in Canada and in many other countries that produce lentil. The main objective of this study was to determine the mode of inheritance of resistance to Ascochyta blight in lentil. Seven cultivars/lines, 4 resistant (ILL 5588, Indian Head, PI 374118 and PI 339283) and 3 susceptible (Eston, Laird and ZT4) were crossed in all possible combinations excluding reciprocals. F1 plants were grown in the greenhouse and spaced F2 plants were grown in an irrigated Ascochyta nursery-. F2 plants were harvested individually and seeds were plated on agar media to determine percentage seed-borne Ascochyta infection. Chi-squared test of goodness-of-fit to various one and two gene ratios were calculated. Data from F2 plants showed that resistance to Ascochyta in Indian Head is governed by a single recessive gene and the resistance in ILL 5588 is governed by one or more dominant genes. F2:3 rows will be grown in an irrigated Ascochyta nursery in the field to confirm the Ascochyta ratings on individual F2 plants