Role of citrus volatiles in host recognition, germination and growth of Penicillium digitatum and Penicillium italicum

S. Droby*, A. Eick, D. Macarisin, L. Cohen, G. Rafael, R. Stange, G. McColum, N. Dudai, A. Nasser, M. Wisniewski, R. Shapira

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

148 Scopus citations

Abstract

Volatiles emitted from wounded peel tissue of various citrus cultivars had a pronounced stimulatory effect on germination and germ tube elongation of both Penicillium digitatum and P. italicum; however, P. digitatum appeared to be more sensitive to the stimulatory action of citrus peel volatiles. When exposed to volatiles from grapefruit peel discs, the percentage of germinated spores of P. digitatum and P. italicum was 75.1% and 37.5%, respectively, whereas germination of controls was 6.8% and 14.7%, respectively. In contrast, Botrytis 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% to 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, ranging from 2.12% to 2.33% and from 0.71% to 1.25%, respectively. All four monoterpenes, limonene, α-pinene, β-pinene and myrcene were stimulatory to P. digitatum and P. italicum but inhibitory to or had no effect on P. expansum and B. cinerea. Germ tube elongation in P. digitatum responded most strongly to limonene and less strongly to α-pinene and β-pinene while myrcene had little effect. In contrast 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 myrecene with the effect of the other compounds being about equal at concentrations of 5 μL or more per plate.

Original languageAmerican English
Pages (from-to)386-396
Number of pages11
JournalPostharvest Biology and Technology
Volume49
Issue number3
DOIs
StatePublished - Sep 2008

Keywords

  • Citrus
  • Hyphal growth promotion
  • Limonene
  • Spore germination
  • Volatiles

Fingerprint

Dive into the research topics of 'Role of citrus volatiles in host recognition, germination and growth of Penicillium digitatum and Penicillium italicum'. Together they form a unique fingerprint.

Cite this