Detection and identification of seed‐borne pathogenic bacteria of imported tomato seeds in Egypt

Abstract

Imported tomato seed lots of different cultivars were assayed for the presence of seedborne bacterial pathogens. The liquid assay method was used for detection of the bacteria, and seed extracts were plated on different semi-selective media. Pseudomonas corrugata and Xanthomonas campestris pv. vesicatoria were detected in 14.7% and 12% of the seed samples tested respectively. These pathogens were identified by means of biochemical, physiological and pathogenicity tests as well as the Biolog GN Microplate System for X. campestris pv. vesicatoria. Both P. corrugata and X. campestris pv. vesicatoria were more easily identified on Tween B and CKTM media than on other media. This is the first report of the occurrence of these important pathogens on tomato seeds in Egypt.

Bacterial Spot of Tomato and Pepper in Africa: Diversity, Emergence of T5 Race, and Management

“…Seeds are important in bacterial spot disease epidemiology, as they often serve as sources of inoculum for the pathogens. In Africa, the bacterial spot pathogens have been routinely isolated from seeds ( Abdalla, 2000 ; Black et al, 2001 ; Opara and Odibo, 2009 ; Shenge et al, 2010 ; Mbega et al, 2012b ). Isolation of pathogens from fruits is also common in Africa.…”

“…Seeds play central roles in vegetable production in Africa ( Abdalla, 2000 ; Opara and Odibo, 2009 ). Much of the tomato and pepper production in Africa results from transplants on nurseries raised by smallholder farmers themselves ( Perez et al, 2017 ).…”

“…The 16S rRNA sequences of recovered strains were identical to X. euvesicatoria and X. gardneri sequences ( Mbega et al, 2012b ). In Egypt, bacterial spot pathogens have also been isolated from imported seeds ( Abdalla, 2000 ; Ashmawy et al, 2020 ). One of the identified species from the imported seeds was designated as X. vesicatoria based on 16S rRNA ( Ashmawy et al, 2020 ).…”

Pseudomonas corrugata: plant pathogen and/or biological resource?

“…Some evidence suggests that the bacterium may be seed‐borne. Contaminated tomato seed lots have been intercepted in Israel (Zutra, 1989) and Egypt (Abdalla, 2000), but as tests are not routinely performed on seeds its incidence is not known. The bacterium from infected plants can be dispersed by rain splash, sprinkler splash and dew, or during handling.…”