科研之友
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摘要
Plant secondary metabolites have important ecological function not only as attractant for pollinators and seed dispersing animals but also as resistance factor against pests and pathogens. Accessions that produce high levels of metabolites involved in resistance are valuable source for sesame breeding. With the aim of identifying genotypes with high content of metabolites potentially involved in resistance against fungal pathogens, 32 sesame accessions were investigated. Metabolites were extracted from leaves, stems and roots and tested against plant pathogenic fungi Macrophomina phaseolina, Alternaria sesami and Fusarium oxysporum. Extracts obtained with 80% ethanol were assayed in microtiter plates and changes in the optical density of the growing fungal cultures were recorded at 550 nm. Most of the extracts had inhibitory effect on all the tested fungal species. Some of the root extracts supported the growth of A. sesami whereas some leaf extracts enhanced the growth of F. oxysporum as compared to the control. The variations observed amongst different sesame accessions lead to the assumption that there is potential to improve plant disease resistance in sesame using metabolic pathway engineering. Crude ethanol extracts of one the accession UCLA1 was fractionated with organic solvents. The inhibition effects of diethylether, chloroform and hexane fractions were higher than of ethanol fraction remaining after extraction with the other solvents. To test whether the synthesis of antifungal metabolites was inducible, plants were exposed to UV light, inoculation with M. phaseolina or F. oxysporum or spraying with CuCl2. The extract of the plants sprayed with CuCl2 were the most inhibitory against M. phaseolina and F. oxysporum in case of leaves extract and against F. oxysporum in case of stem extract.
- 出版日期2015
