Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Estimation of infection by Pseudomonas solanacearum in weed and non host plants.

Abstract

Field studies were conducted in the Kumaon Hills, Uttar Pradesh, between 1988 and 1990 to determine the presence of Pseudomonas solanacearum in the rhizosphere, rhizoplane and root tissues of weeds and non-host plants found with potatoes. The plants sampled were Chenopodium album, Ranunculus sceleratus, Cannabis sativa [hemp], Scutellaria scandens, Arabidopsis thaliana, Solanum xanthocarpum, Spergula arvensis, Galium aparine, Ageratum conyzoides, Datura stramonium, Capsicum baccatum, Polygala spp., Oxalis spp., Vicia spp., Antirrhinum spp., Blumea spp., Valeriana spp., Lathyrus spp., Nepata [Nepeta] spp., Artemissia [Artemisia] spp., Polygonum spp., turmeric, cabbages and maize. Samples were taken from the field from the different regions of the soil/plant complex and incubated on selected media. Results showed that low populations of P. solanacearum were found in the rhizosphere, rhizoplane and root tissues of most symptomless hosts, compared to high populations observed in plant roots showing visible symptoms. It was found that only D. stramonium, S. xanthocarpum, Antirrhinum spp. (weed hosts) and C. baccatum (non-host) showed visible symptoms on inoculation, while all the other species carried the pathogen population at 102-106 CFU/g soil in the rhizosphere, 0-105 CFU/ml per root in the rhizoplane and 0-106 CFU/ml per root in root tissue without showing symptoms. It was concluded that the presence of P. solanacearum without symptoms in weeds and crop plants may provide a continuous inoculum for potatoes grown near or with them.