Epiphytic Survival of Pseudomonas syringae pv. glycinea on Symptomless Soybean and Weeds

Abstract

During the period of 1991–1994 investigations were carried out to determine the epiphytic survival of Psgl on the main host — soybean and on weeds (25 species). The samples were gathered from diseased, healthy and symptomless soybean sowings and from uncultivated fields in different regions of the country. Psgl occurred on symptomless foliage, fiower buds and the blossoms of the natural host — soybean, during the whole vegetation in high temperature and low humidity, and epiphytically on the annual late spring weeds. The bacterium did not occur epiphytically on weeds in heaithy bean fields or in uncultivated fields. Psgl was detected in a resident phase on the annual weeds: Amaranthus retroflexus, Portulaca oleraceae, Datura stramonium, Solanum nigrum, Chenopodium album and Polygonum lapathifolium. These species are regular weed hosts for epiphytic occurrence of Psgl when they are gathered from soybean fields with a registered disease.