Screening of lentil genotypes for resistance against collar rot, Stemphylium blight and rust diseases

摘要

Lentil (Lens culinaris Medik), is an edible pulse having the third-highest level of protein, by weight, of any legume or nut, after soybean and hemp. In India, it is grown in the winter season and 90 % of its production comes from Uttar Pradesh, Madhya Pradesh, Bihar and West Bengal. Diseases are the major biotic production constraints in obtaining higher lentil yields. Among them, collar rot (Sclerotium rolfsii Sacc), foliar blight (Stemphylium botryosum Wallr.) and rust (Uromyces vicia- fabae Pers.J. Schroet) are the most destructive ones causing yield losses to the tune of 50-60% (Bakr, 1991; Erskine and Sarker, 1997) in India. Collar rot is considered as an important and destructive disease of pulses in almost all legume-growing countries of the world. It causes seedling death at early stage resulting in very poor plant stand, which ultimately produces very low yield. Stemphylium blight is a serious threat to lentil cultivation in South Asia, including Bangladesh, and in North America (Vandenberg and Morrall, 2002; ICARDA, 2004). The pathogen has wide geographic distribution and causes substantial yield loses annually in Bangladesh, India, Ethiopia, Morocco and Pakistan. Rust disease causes up to 70% yield loss, although occasional complete crop losses were observed (Negussie et al., 2005). Incidence of the disease varies considerably from year to year depending upon environmental conditions. Early sole or combined incidence of diseases may lead to complete loss of the crop (Sepulveda, 1985).