Screening common bean germplasm for resistance to genetically diverse Sclerotinia sclerotiorum isolates from Argentina

Abstract

White mold caused by Sclerotinia sclerotiorum (Lib.) de Bary is a devastating disease that affects the common bean (Phaseolus vulgaris. L) crop worldwide. In Argentina, white mold has been detected in all bean production areas, reaching seed yield and quality losses up to 100% on susceptible common bean cultivars under favorable weather conditions. The aim of this study was to screen the physiological resistance of 20 common bean accessions to five genetically distinct isolates of S. sclerotiorum collected from the main common bean growing area of Argentina, using the greenhouse straw test. The white mold reaction was scored at 7, 14, and 21 days post-inoculation using a 1 (no disease symptoms) to 9 (severely diseased or dead plants) scale and the area under the disease progress curve (AUDPC) was determined. Highly significant differences (p < 0.001) were observed between isolates, accessions and genotype x isolate interaction at the three evaluations dates. All cultivars and lines were susceptible at the end of the assessment, except line A 195 which was resistant to white mold against the five isolates tested and was significantly different from all accessions. This work represents a valuable contribution to regional breeding programmes aimed to obtain cultivars with durable resistance.

Mitigating against Sclerotinia Diseases in Legume Crops: A Comprehensive Review

“…Legumes are not spared the negative consequences of Sclerotinia disease. It is known for causing disease among legumes such as groundnut (Arachis hypogaea L.), soybean (Glycine max L.), common bean (Phaseolus vulgaris L.), faba bean (Vicia faba L.), alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.), chickpea (Cicer arietinum L.), and lupin (Lupinus albus L.) [64,[68][69][70][71][72][73][74]. These common legumes are known as grain or food legumes [75].…”

Characterization of fungal pathogens and germplasm screening for disease resistance in the main production area of the common bean in Argentina

“…In Argentina, the physiological resistance of 20 common bean accessions (cultivars and lines) was assessed at 7, 14, and 21 days post-inoculation with five genetically distinct isolates of S. sclerotiorum collected from the main common bean growing area of NWA ( Aban et al, 2020 ). These isolates were previously characterized using URP and SSR molecular markers, MCGs and pathogenicity tests ( Abán et al, 2018 , Aban et al, 2020 ).…”

“…In Argentina, the physiological resistance of 20 common bean accessions (cultivars and lines) was assessed at 7, 14, and 21 days post-inoculation with five genetically distinct isolates of S. sclerotiorum collected from the main common bean growing area of NWA (Aban et al, 2020). These isolates were previously characterized using URP and SSR molecular markers, MCGs and pathogenicity tests (Abán et al, 2018, Aban et al, 2020. Based on the modified Petzoldt and Dickson scale (Terán et al, 2006), all cultivars and lines were susceptible at the end of the assessment, except line A 195, which was resistant to WM against the five isolates tested and was significantly different from all accessions.…”