Plant Disease (2014) 98, 1241-1247
Yu Pin Li, Ming Pei You and Martin J. Barbetti (2014)
Species of Pythium associated with seedling root and hypocotyl disease on common bean (Phaseolus vulgaris) in Western Australia
Plant Disease 98 (9), 1241-1247
Abstract: The occurrence and distribution of Pythium spp. were determined by collecting isolates of Pythium from common bean (Phaseolus vulgaris) plants showing root or hypocotyl disease symptoms from different areas of Western Australia in 2012. Eight different Pythium species (Pythium conidiophorum, P. diclinum, P. intermedium, P. irregulare, P. lutarium, P. mamillatum, P. pachycaule, and P. perplexum) were isolated and identified according to molecular sequences. P. irregulare was the most widespread Pythium sp. All species, except P. perplexum, were pathogenic to the hypocotyl and root of common bean. We believe this is the first report of P. intermedium as a pathogen on common bean worldwide. This is also the first report of P. conidiophorum, P. intermedium, P. lutarium, P. mamillatum, P. pachycaule, and P. diclinum as pathogens on common bean in Australia and the first report of P. irregulare as a pathogen on common bean in Western Australia. P. intermedium was the most pathogenic species, causing the most severe disease on 'Gourmet Delight' (percent root disease index [%RDI] 75 ± 2.9 and percent hypocotyl disease index [%HDI] 59.2 ± 3.2) and 'Pioneer' (%RDI 75 ± 2.9 and %HDI 65.8 ± 3.2). That the relative susceptibility or resistance (the ability of a plant to reduce the extent of invasion by the pathogen) of a given bean variety to one Pythium sp. was, in general, similar across the other Pythium spp. was an important finding, because this opens up opportunities to utilize a single virulent isolate of one Pythium sp. to identify general resistance to a wider spectrum of Pythium spp.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Ming Pei You
Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
general biology - morphology - evolution
