First report of Penicillium georgiense as a fungal pathogen of onion (Allium cepa L.)

Published Date
Crop Protection
June 2015, Vol.72:83–89, doi:10.1016/j.cropro.2015.02.009
Short communication

• Author 

• Ji Yeon Oh ^a,b,1
• Gyung Deok Han ^a,1
• Jin-Ju Jeong ^a
• Mee Kyung Sang ^a,c
• Se-Chul Chun ^d
• Ki Deok Kim ^a,,

• aLaboratory of Plant Disease and Biocontrol, Division of Biotechnology, Korea University, Seoul 136-713, Republic of Korea
• bInstitute of Life Science and Natural Resources, Korea University, Seoul 136-713, Republic of Korea
• cDivision of Agricultural Microbiology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 560-500, Republic of Korea
• dDepartment of Molecular Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea

Received 13 December 2014. Revised 13 February 2015. Accepted 14 February 2015. Available online 14 March 2015. 

Highlights

• •
  Penicillium sp. GR-68 was identified by morphological and molecular analyses.
• •
  Isolate GR-68 was identified as Penicillium georgiense.
• •
  This fungus was pathogenic on onion bulbs.
• •
  This is the first report of P. georgiense as a fungal pathogen of onion bulbs.

Abstract

Previously, we identified Aspergillus awamori, Fusarium oxysporum, Penicillium brasilianum, and Rhizopus oryzae as the predominant fungal species in onion bulbs in Korea. In that study, we also observed other minor Penicillium spp., among which a specific species was often isolated from yellowish sunken lesions of the bulbs and usually appeared with A. awamori. Hence, in this study, we identified this unknown Penicillium sp. GR-68 by molecular and morphological characteristics and tested its pathogenicity against onion bulbs. As a result, isolate GR-68 was identified as Penicillium georgiense by phylogenetic analyses using neighbor-joining and maximum-likelihood methods with internal transcribed spacer (ITS) and β-tubulin region sequences. When the micro- and macro-morphological characteristics of isolate GR-68 were compared with those of the reference isolate NRRL 35509^T of P. georgiense, isolate GR-68 was similar to the reference isolate. In the pathogenicity tests, isolates GR-68 and NRRL 35509^T were found to be pathogenic to onion bulbs, where hole-inoculated bulbs showed symptoms of weak yellow halos or yellowish sunken lesions. In addition, the fungal isolates were re-isolated from the symptomatic lesions on the inoculated bulbs and re-confirmed as P. georgiense by the ITS and β-tubulin region sequence analyses. To the best of our knowledge, this is the first report of P. georgiense as a fungal pathogen of onion bulbs.

Keywords

Allium cepa L.

Fungal identification

Onion

Penicillium georgiense

Postharvest disease

---

Fig. 1.

Fig. 2.

Fig. 3.

 Table 1

Table 1.

Fig. 4.

Fig. 5.

• ∗ 
  Corresponding author.

Copyright © 2015 Elsevier Ltd. All rights reserved.

For further details log on website :
http://www.sciencedirect.com/science/article/pii/S0261219415000599