Resistance to ascochyta blights of cool season food legumes

Abstract

Ascochyta blights are the most important diseases of cool season food legumes (peas, lentils, chickpeas, and faba beans) and are found in nearly all production regions. Despite having the same common disease name, the pathogen species differ for each of the crops. These diseases cause serious yield losses under favourable cool and humid conditions. Planting resistant cultivars is often the first choice and most economical means in managing the diseases. Therefore breeding for resistance to ascochyta blights has been an important objective of many cool season food legume research programmes. Systematic screening of germplasm collections at international research centres and other national research programmes have identified useful resistance sources that have been used successfully to breed resistant or tolerant cultivars. Genetic studies have revealed inheritance patterns of the resistance genes. Genetic linkage analyses and QTL mapping have identified molecular markers that could be useful for markerassisted selection and gene pyramiding. In general, research towards developing resistance to ascochyta blights in cool season food legume faces mainly two limitations: the lack of availability of efficient resistance sources and the lack of a good understanding of the variability of the pathogen populations. Research efforts to alleviate these limitations should be pursued. Given that modern technologies of marker development and genomics are available, further advances in deploying resistance to manage ascochyta blights in this group of legume crops will depend on concerted efforts in developing accurate screening procedures with adequate knowledge of pathogen variability and identification of additional sources of resistance.

Endogenous Auxin Content Contributes to Larger Size of Apple Fruit

“…Figure 3); thus, ploidy could not explain the larger fruit size of GLF. Previous studies have revealed that cell size and number play important roles in affecting the size of different fruit, including tomato (Cheniclet et al, 2005), sweet cherry (Olmstead et al, 2007), and peach (Guo et al, 2018). Here, we found that the large fruit size of GLF correlated with cell size (Figure 2C).…”

“…Fruit size is determined by two factors, cell number and/or cell size (Scorzal et al, 1991;Olmstead et al, 2007;Malladi and Hirst, 2010). Previous research has reported that cell number is the major factor influencing fruit size.…”

Host-specific toxins: effectors of necrotrophic pathogenicity

“…Many other Pleosporales pathogens closely resemble S. nodorum in exhibiting foliar necrotrophic symptoms and toxic culture filtrates (Strange, 2007). Examples include Pyrenophora teres (Sarpeleh et al ., 2007) and the legume pathogens in the Ascochyta group (Hernandez‐Bello et al ., 2006; Muehlbauer and Chen, 2007). A critical search for HSTs using the techniques of subfractionation of culture filtrates and genome sequencing is surely warranted.…”

Insights to plant–microbe interactions provide opportunities to improve resistance breeding against root diseases in grain legumes

“…These phytopathogenic fungi are responsible for severe leaf and stem spots and root rots on many legume host plants including pea, chickpea, lentil, and faba bean (Muehlbauer & Chen, 2007). The genus Fusarium comprises several species that can cause severe root rot impeding cultivation of pea and common bean worldwide (Coleman, 2016;Hwang, Chang, Strelkov, Gossen, & Howard, 2014).…”