Black root rot

Pseudomonas fluorescens CHAO HCN. 2,4-Diacetylphlo roglucinol, pyoluteorin Thielviopsis basicola Tobacco Black root rot 118... 

C. Voisard, C. Keel, D. Haas, and G. Defago, Cyanide production by P.seudomonas fluorescens helps suppress black root rot of tobacco under gnotobiotic conditions, EM BO J 8 35 (1989). 

Tobacco blue mold tobacco mosaic tobacco ringspot black shank black root rot Peronospora tabacina 5 virus virus Phytophthora parasitica Thielaviopsis basicola, 31,32 1.3 1.3 33 34... 

Whole plant wilted or collapsed. Causes Black root rot red stele disease Verticillium wilt strawberry crown moth larvae strawberry crown borers. To discover which cause applies, remove a plant from the soil and examine its roots. Rotting black roots indicate black root rot plants are stunted, produce few fruits, and may die at fruiting time. See the opposite page for an illustration of black root rot. 

Whole plant wilted cn collapsed. Cause Black root rot. Stunted -... 

Amaranthus and, 17 Armillaria, 403,403 avocado and. 32 bean and, 33 Betula and, 401 black (see Black root rot) Campanula and, 58-59... 

Antibiotic-producing fluorescent Pseudomonas strains have been readily isolated from soils that naturally suppress diseases such as take-all (a root and crown disease) of wheat, black root rot of tobacco, and fusarium wilt of tomato [145]. 

Delon, R. and M.-N. Pululu The chemical control of tobacco black root rot Beitr. Tabakforsch. Int. 14 (1989) 189-195. 

Unbehaun, L.M. and L.D. Moore Pectic enzymes associated with black root rot of tobacco Phytopathology 60... 

Many species of plants, including some fungi, bacteria, algae, and higher plants, produce cyanide as a metabolic product. Some species of soil bacteria suppress plant diseases caused by soilborne pathogens by producing metabolites with antibiotic activity. Certain strains of Pseudomonas fluorescens, a soil bacterium, suppress black root rot of tobacco... 

The activities of scopoletin (6-methoxy-7-hydroxycoumarin) and esculetin (6,7-dihydroxycoumarin) were compared to each other and to those of their respective glucosides, scopolin and esculin (Table TV). The dihydroxy-coumarin was found to be just as active as the methoxy-hydroxy-compound. Thus, the presence of a free hydroxyl group at position-6 is not required for activity. Surprisingly, substitution of a glucose on the hydroxyls of both compounds resulted in the complete loss of activity. Gasser (3) found similar results with the activity of scopolin towards black root rot. 

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