This study investigated the biofumigation potential of nine Brassica species/cultivars by determining the levels of 2-propenyl glucosinolate in their roots and shoots, and their in-vitro suppression of four major soil...This study investigated the biofumigation potential of nine Brassica species/cultivars by determining the levels of 2-propenyl glucosinolate in their roots and shoots, and their in-vitro suppression of four major soil-borne pathogens of vegetable crops. Hydrolysis of 2-propenyl GSL produces volatile isothiocyanate (ITC) compounds which are known to have anti-fungal activity. HPLC results showed that 2-propenyl GSL only occurred in root and shoot residue of flowering plants of four Brassica cultivars developed for green manuring (Caliente 199?, Mustclean?, Nemfix? and BQ Mulch?) and in the standard (mustard seed meal) treatment Fumafert?. Levels of 2-propenyl GSL varied several fold within the four Brassica cultivars, with 77-88% of the total concentrations recorded in the shoot tissues. In in vitro assays, the level of fungal suppression by volatiles emitted by hydrated shoot and root residues related to their content of 2-propenyl GSL, and the dose of residue applied to five soilborne test pathogens (S. minor, Rhizoctonia solani, Fusarium oxysporum, Pythium dissotocum and Rhizoctonia solani). The variation in 2-propenyl GLS levels found in the Brassica green manure crops tested provides scope for selecting cultivars with greater potential for biofumigation, and to control multiple soil-borne disease problems in vegetable farms.展开更多
文摘This study investigated the biofumigation potential of nine Brassica species/cultivars by determining the levels of 2-propenyl glucosinolate in their roots and shoots, and their in-vitro suppression of four major soil-borne pathogens of vegetable crops. Hydrolysis of 2-propenyl GSL produces volatile isothiocyanate (ITC) compounds which are known to have anti-fungal activity. HPLC results showed that 2-propenyl GSL only occurred in root and shoot residue of flowering plants of four Brassica cultivars developed for green manuring (Caliente 199?, Mustclean?, Nemfix? and BQ Mulch?) and in the standard (mustard seed meal) treatment Fumafert?. Levels of 2-propenyl GSL varied several fold within the four Brassica cultivars, with 77-88% of the total concentrations recorded in the shoot tissues. In in vitro assays, the level of fungal suppression by volatiles emitted by hydrated shoot and root residues related to their content of 2-propenyl GSL, and the dose of residue applied to five soilborne test pathogens (S. minor, Rhizoctonia solani, Fusarium oxysporum, Pythium dissotocum and Rhizoctonia solani). The variation in 2-propenyl GLS levels found in the Brassica green manure crops tested provides scope for selecting cultivars with greater potential for biofumigation, and to control multiple soil-borne disease problems in vegetable farms.
