Articles
A molecular tool to identify fungal postharvest pathogens of pear
Article number
1451_13
Pages
95 – 98
Language
English
Abstract
The pome fruit industry is facing the loss of several widely used fungicides, which have suppressed fungal decay of apples and pears for many decades.
While grey mould and blue mould caused by Botrytis cinerea and Penicillium expansum, respectively, are well known storage pathogens worldwide, less is known about the identity and presence of other fungal species that can lead to heavy crop losses.
Therefore, a screening method, PCR-RFLP of the internal transcribed spacer regions ITS1 and ITS2 using the TasI restriction enzyme, was optimized to determine which of the potential 17 postharvest decay-causing pathogens are present in Western Cape orchards in stored pears.
Species identification was verified with phylogenetic analysis of barcoding genes such as translation elongation factor 1 alpha.
The vast majority of symptomatic pears showed blue mould symptoms (Penicillium sp.; 33-57% of decayed fruit), closely followed by isolations of Alternaria alternata, which mostly caused superficial calyx or stem end mould (up to 50% in individual orchards). Of the 1200 fungal isolates collected, most constituted known pear pathogens of the Botryosphaeriaceae family and could be distinguished to genus level using the PCR-RFLP method.
Knowledge of the occurrence of the pathogens will enable more targeted and integrated management strategies in future.
While grey mould and blue mould caused by Botrytis cinerea and Penicillium expansum, respectively, are well known storage pathogens worldwide, less is known about the identity and presence of other fungal species that can lead to heavy crop losses.
Therefore, a screening method, PCR-RFLP of the internal transcribed spacer regions ITS1 and ITS2 using the TasI restriction enzyme, was optimized to determine which of the potential 17 postharvest decay-causing pathogens are present in Western Cape orchards in stored pears.
Species identification was verified with phylogenetic analysis of barcoding genes such as translation elongation factor 1 alpha.
The vast majority of symptomatic pears showed blue mould symptoms (Penicillium sp.; 33-57% of decayed fruit), closely followed by isolations of Alternaria alternata, which mostly caused superficial calyx or stem end mould (up to 50% in individual orchards). Of the 1200 fungal isolates collected, most constituted known pear pathogens of the Botryosphaeriaceae family and could be distinguished to genus level using the PCR-RFLP method.
Knowledge of the occurrence of the pathogens will enable more targeted and integrated management strategies in future.
Authors
M. Farquhar, M. Kotze, M.J. Richard, C.L. Lennox, J.C. Meitz-Hopkins
Keywords
fungal pear diseases, molecular detection, pear decay
Online Articles (37)