STRAINS OF Erwinia carotovora THE CAUSAL AGENT OF SOFT ROT OF SOME VEGETABLES AND ITS CONTROL IN EGYPT

Abstract

This study is aimed to isolate and identification the important bacterial species, the causal agent of soft rot disease in some vegetables, and study of their host range. Samples of some vegetables showing the natural soft rot disease symptoms were collected from the storages or commercial marketing locations in Giza and Beni Suef governorates. The results obtained can be summarized in the following points:

1. Seventeen bacterial isolates were obtained as follows: four isolates from potato tubers Ecc1, Ecc2, Ecc3 and Ecc4; one isolate from sweet potato tubers Ecc5; three isolates from cucumber fruits Ecc6, Ecc7 and Ecc8; three isolates from carrot roots Ecc9, Ecc10 and Ecc11; two isolates from eggplants Ecc12 and Ecc13; one isolate from red sweet pepper Ech1; two isolates from chili fruit Ecc14 and Ecc15 and one isolate from tomato fruits Ech2. 2. Bacterial isolates showing difference in their ability to grow in NaCl

at 5% solution, all bacterial isolates were grow except isolates Ecc13 and Ecc15 couldn't grow, respectively. All bacterial isolates were not sensitive to the antibiotic erythromycin, except isolates Ech1 and Ech2 were sensitive. 3. The bacterial isolates showing difference in their pathogenicity on the different hosts as well as the isolates were differed in their ability for fermentation of tested sugars viz. arabinose, dextrose, fructose, lactose, maltose, mannitol, mannose, rhamnose, salicin, starch, xylose, glycerol and sucrose producing acid & gas or acid only.