Macrophomina phaseolina . [Descriptions of Fungi and Bacteria

Abstract

Abstract A description is provided for Macrophomina phaseolina . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Plurivorous; Young (1949) lists 284 hosts. DISEASES: Charcoal rot, ashy stem blight. The most frequent symptoms are a dry or wet, dark rot of the lower stem. In maize and sorghum this usually occurs near maturity; the cortex is destroyed, lodging may take place and numerous sclerotia are found on the vascular fibres (16: 310; 24: 96; 25: 109). Leaf lesions also occur on jute and legumes (4: 349; 23: 107; 26: 139). Stem rot and canker can be severe in potato, cotton and groundnut (15: 148; 24: 202, 228, 503; 34: 541; 47, 378). In conifers and many crops the fungus causes damping-off (13: 344; 17: 115; 21: 275; 26: 139; 35: 42; 38: 550; 40: 193; 45, 2846; 48, 2030). GEOGRAPHICAL DISTRIBUTION: Widespread in the tropics and subtropics. TRANSMISSION: Through plant debris in soil. Seed-borne spread may be important in some crops. Both sclerotia and pycnidia can occur on the seed surface and under the seed coat (18: 82; 27: 71). Sclerotia are probably the main source of infection which also occurs through conidia (26: 139). Sclerotia showed no loss in viability after 8 months and the fungus was recovered from cotton stubble after 24-42 weeks (25: 56; 35: 607).