Important Phytopathogenic Bacteria
Sr.No | Genus | Family | Gram Reaction | Characters | Symptoms produced on host | Example |
1 | Pseudomonas | Pseudomona deveae | -Ve | 1. Rod straight to curved, size 0.5-1 X 1.5-4 mue m, one to many polar flagella.2.Colonies not yellow, do not produce acid from lactose. | Leaf spot, blights, vascular wilts, soft rots, canker. | 1. Brown rot or bacterial wilt of potato.2 Bacterial wilt of brinjal and tomato. |
2 | Xanthomonas | Pseudomona deveae | -Ve | 1. Straight rods, size 0.4-1X 1.2 -3m. One polar flagellum present.2. Colonies yellow due to Xanthomonadin, produce acid from lactose. | Leafspot, fruit spots, blight, canker | 1. Citrus canker, 2. Black arm of cotton,3.Blight of paddy. |
3 | Agrobacterium | Rhizobiaceae | -Ve | 1. Rod shaped, size 0.8 X 1.5 -3 mue m. 1 to 4 peritrichous flagella.2. Colonies mostly white do not hydrolyze starch. | Crown Gall | Crown Gall of stone fruit roses. |
4 | Erwinia | Enterobacteriaceae | -Ve | 1. Straight rods, size 0.5-1, 0-3.0 mue m , several peritrichous flagella. | Fire blight, wilt soft rot. | 1. Fire blight of apple.2. Soft rot of vegetables. |
5 | Clavibactor (Corynebacterium) | Enterobacteriaceae | +Ve | Straight to straightly curved rods, 0.5-0.9X 1.5 -4.0Mue m. non motile but some species are motile by one or two polar flagella. | Wilt | Wilt of potato ad Tomato |
6 | Streptomyces | Streptomycetaceae | +Ve | Slender branched hyphae without cross walls 0.5-2 mue m diameter. | Scab | Potato scab |