© 2016, Koninklijke Nederlandse Planteziektenkundige Vereniging.Identifying combined abiotic (waterlogging) and biotic (Pythium) stress resistance is critical if common bean (Phaseolus vulgaris) productivity in disease-prone regions with irregular but intensive rainfall patterns is to be productive. In this study, 194 common bean varieties from 37 countries were screened, documenting the effects of waterlogging on damping-off, as well as hypocotyl and root disease severity caused by Pythium irregulare. Varieties Quqa lecherita [Percent Hypocotyl Disease Index (%HDI) 33.3, Percent Root Disease Index (%RDI) 37.5] and PAC 18 (%HDI = 40.0, %RDI = 49.9) showed the greatest resistance to Pythium. Variety RIZ 102 showed the most tolerance to waterlogging with the mean tolerance value 3.6. Navy Veracruz (%HDI unwaterlogged 50.0, waterlogged 30.0; %RDI unwaterlogged 68.8, waterlogged 45.8), Negro argel (%HDI unwaterlogged 47.5, waterlogged 45.0; %RDI unwaterlogged 56.3, waterlogged 43.8), and Phavul 77 (%HDI unwaterlogged 50.0, waterlogged 43.3; %RDI unwaterlogged 56.3, waterlogged 41.7) had combined resistance to P. irregulare and tolerance to waterlogging. This is the first study to identify combined abiotic and biotic stress resistances in common bean. There were significant correlations between hypocotyl disease severity (without waterlogging) with country of origin, with days to flowering, and with seed lustre, highlighting promising foci in developing improved bean varieties. The results demonstrated that there is ample genetic variation in common bean that can be exploited to combine root/hypocotyl disease resistance and waterlogging tolerance into new cultivars to suit a variety of environments challenged by both root/hypocotyl disease and periodic waterlogging.
Li, Y., You, M., Norton, S., & Barbetti, M. (2016). Resistance to Pythium irregulare root and hypocotyl disease in diverse common bean (Phaseolus vulgaris) varieties from 37 countries and relationships to waterlogging tolerance and other plant and seed traits. European Journal of Plant Pathology, 146(1), 147-176. https://doi.org/10.1007/s10658-016-0901-2