The role of volatile compound in recognition and germination of Penicillium digitatum and Penicillium italicum on citrus fruit
Droby S, Eick A, Macarisin D, Cohen L and Rafael G
Program and Abstracts, 11th International Citrus Congress (ISC Congress), 26-20 October 2008, Wuhan, China. 333 pages.
2008
บทคัดย่อ
The role of volatile compound in recognition and germination of Penicillium digitatum and Penicillium italicum on citrus fruit
Volatiles emitted from wounded peel tissue of various citrus cultivars had a pronounced stimulatory effect on germination and germ tube elongation of both P. digitatumand P. italicum; however, P. digitatum appeared to be more sensitive to the stimulatory action of citrus peel volatiles. When exposed to volatiles from grapefruit, the percentage of germinated spores of P. digitatum and P. italicum was 10 and 5 fold, respectively as compared to the control. In contrast, B. cinerea and P. expansum were either not affected or inhibited by the peel volatiles. GS-MS analysis of volatiles present in the peel of various citrus fruit cultivars revealed that limonene is the major fruit peel volatile. Its percentage ranged from 89-95% at the early stages of fruit development throughout the harvest season. Myrcene and α-pinene made up the second and third greatest amounts among the volatiles found in these oils. All four monoterpenes, limonese α-pinene, β-pinene and myrcene were stimulatory to P. digitatumand P. italicum but inhibitory to or had no effect on P. expansumand B. cinerea. Germ tube elongation in P. digitatumresponded most strongly to limonene and less strongly to α-pinene and β-pinene while myrcene had little effect. In P. italicum myrcene stimulated germ tube elongation the most followed by limonene, with α-pinene, and β-pinene being about equal. Germination of P. italicum conidia was highest in response to myrcene with the effect of the other compounds being about equal at concentrations of 5 µl or more per plate.