Pathogen Lasiodiplodia Research Articles

Isolation of an α-methylene-γ-butyrolactone derivative, a toxin from the plant pathogen Lasiodiplodia theobromae

Lasiodiplodia theobromae is known as a multi-infectious microorganism that causes considerable crop damage, particularly to tropical fruits. When the fruits are infected by L. theobromae, the typical symptom is the appearance of black spots on the surface of the infected fruit. When injected in to the peel of banana, the culture filtrate of L. theobromae induced formation of black spots. The structure of the isolated compound responsible for this effect was determined to be (3 S,4 R)-3-carboxy-2-methylene-heptan-4-olide on the basis of analysis of MS, IR, and 1H and 13C NMR spectroscopic data, including HMQC, HMBC, and 1H– 1H COSY experiments. The active compound was not only isolated from the culture filtrate derived from potato dextrose medium, but also from the extract of infected peels of bananas.

A Review ofLasiodiplodia theobromaewith Particular Reference to its Occurrence on Coniferous Seeds

SYNOPSIS The fungal pathogen Lasiodiplodia theobromae has been associated with numerous plant diseases on a wide variety of hosts. Conifers seem to be particularly susceptible to infection, although the true parasitic status of the fungus is still largely unresolved. In South Africa, L. theobromae is associated with discolouration and reduced germination of Pinus elliottii seeds. The mode of seed infection is, however, still unclear. This review attempts to critically summarise current knowledge pertaining to infection of coniferous species by L. theobromae, with special emphasis on its ability to act as a seedborne pathogen and means of controlling it.