Screening techniques and sources of resistance to foliar diseases caused by major necrotrophic fungi in grain legumes

Abstract

Necrotrophic pathogens of the cool season food legumes (pea, lentil, chickpea, faba bean and lupin) cause wide spread disease and severe crop losses throughout the world. Environmental conditions play an important role in the development and spread of these diseases. Form of inoculum, inoculum concentration and physiological plant growth stage all affect the degree of infection and the amount of crop loss. Measures to control these diseases have relied on identification of resistant germplasm and development of resistant varieties through screening in the field and in controlled environments. Procedures for screening and scoring germplasm and breeding lines for resistance have lacked uniformity among the various programs worldwide. However, this review highlights the most consistent screening and scoring procedures that are simple to use and provide reliable results. Sources of resistance to the major necrotrophic fungi are summarized for each of the cool season food legumes. Marker-assisted selection is underway for Ascochyta blight of pea, lentil and chickpea, and Phomopsis blight of lupin. Other measures such as fungicidal control and cultural control are also reviewed. The emerging genomic information on the model legume, Medicago truncatula, which has various degrees of genetic synteny with the cool season food legumes, has promise for identification of closely linked markers for resistance genes and possibly for eventual map-based cloning of resistance genes. Durable resistance to the necrotrophic pathogens is a common goal of cool season food legume breeders.

Development of screening techniques and identification of new sources of resistance to Ascochyta blight disease of chickpea

“…Breeding of chickpea for resistance to AB is an important goal worldwide but is often limited due to the absence of high levels of resistance in chickpea germplasm which along with the highly variable pathogen, has precluded the development of varieties with both high and durable resistance (Knights and Siddique 2002;Pande et al 2005;Chen et al 2004, Tivoli et al 2006. The ICARDA scientists have developed more than 3000 lines with moderate resistance to AB (Malhotra et al 2003), but the frequency of highly resistant lines to AB is generally low (Iqbal et al 2002;Atanasova and Mihov 2009).…”

Genetic diversity and virulence of Colletotrichum lupini isolates collected in Chile

“…The isolates classified as C. lupini by Nirenberg et al (2002) and the majority of the worldwide isolates of lupin anthracnose fit within the highly homogeneous group A1 from C. acutatum that was described by Sreenivasaprasad & Talhinhas (2005). After the description given by Nirenberg et al (2002), C. lupini is now accepted as the causal agent of anthracnose in lupins (Lotter & Berger 2005;Tivoli et al, 2006;Thomas et al, 2008;Yang et al, 2008).…”

Legume Crops Phylogeny and Genetic Diversity for Science and Breeding

“…Other abiotic stresses, like heat tolerance and water logging, also require attention. Identifying and incorporating host resistance to biotic stresses is needed (Infantino et al, 2006;Tivoli et al, 2006;Pérez-de-Luque et al, 2010;Sillero et al, 2010).…”