ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Inhibitory activity of yeasts isolated from fig fruits against Penicillium digitatum.

Arras, G.; Dessi, R.; Sanna, P.; Arru, S.;

Acta Horticulturae Year: 1999 Issue: No. 485 Pages: 37-46 Ref: 20 ref.

1999

บทคัดย่อ

The isolation of 129 yeasts from the carposphere of fig fruits capable of inhibiting P. digitatum development on artificially wounded citrus fruits is reported. The wounds were challenged with a pathogen suspension (105 or 106 conidia/ml) after yeast inoculation (108 cells/ml). The best results (96-100% inhibition) were obtained with the following strains: 5A of Pichia guilliermondii and 43E, 44E and 69F of Candida famata [Torulopsis candida]. One isolate, 43E, showing particularly high activity, was further tested in order to better characterize its mode of action against the pathogen. Mechanisms of action were primarily competition for space and nutrients through colonization of pathogen hyphae, as seen in scanning electron micrograph (SEM) photographs; it was not possible to detect antibiotic or toxic substance production by the yeast. The isolate 43E of C. famata was found to be compatible with high thiabendazole (TBZ) concentrations (5 g/litre). A test was carried out to determine the inhib

itory activity at lower cell concentrations than usual (107, 106 and 105/ml) and in the presence of TBZ. The fungicide was employed at about one-seventh and one-fifteenth of the concentration in commercial use. The results show that the 43E strain of C. famata, when used together with 0.1 g TBZ/litre at a concentration of 106 cells/ml, gives significantly better disease control than either TBZ or the yeast alone.