Phytotoxins distribution

Guenzi and McCalla (1966) extracted soils with various extractants, and by paper chromatography identified several phenolic acids. The concentrations were probably too low to produce appreciable effects on plant growth if we assume even distribution throughout the soil. Much higher concentrations of the phytotoxins would be expected in the immediate vicinity of decaying crop residues. 

The inhibitory effect of partitioned extracts of mungbean stems show that the naturally occurring allelopathic phytotoxins were distributed throughout the water, I-butanol, ethyl ether, and ethyl acetate fractions, which indicates that several types of compounds are represented. 

T. from plants (phytotoxins) include both high- and low-molecular weight substances. Examples of the former are the lectins distributed in legumes (abrin, con-canavalin A, crotin, phasin, ricin). The low-molecular weight plant T. are more numerous and of greater diversity, including the cardiac glycosides, saponins. 

P. Hess and J. Aasen, Chemistry, origins and distribution of yessotoxin and its analogues, in L.M. Botana (Ed.), Phytotoxins, Chemistry and Biochemistry, Blackwell Publishing, Ames, Iowa, 2007, pp. 187-202. 

The genus Alternaria is widely distributed in nature, and a number of Alternaria spp are pathogenic to plants (66). A. alternata f sp. lycopersici was isolated from susceptible asc/asc) tomatoes with stem canker disease (33,40, 48). The active phytotoxin responsible... 

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