Abstract

Bitter rot and Glomerella leaf spot (GLS) are two distinct diseases of apple fruit and foliage caused by members of the ascomycete fungal genus Colletotrichum. While GLS is restricted to subtropical and in some areas to temperate climates, bitter rot is responsible for significant yield loss worldwide, particularly during the post-harvest period. Initially thought to be caused by just two species of Colletotrichum, C. acutatum and C. gloeosporioides, advances in molecular biology and sequencing techniques enabled the identification of 25 different species capable of causing bitter rot and/or GLS of apple belongs to the C. gloeosporioides species complex (CGSC), C. acutatum species complex (CASC) and C. boninense species complex (CBSC). Three species (C. gloeosporioides, C. fructicola, and C. chrysophilum) of CGSC cause both bitter rot and GLS, 18 species (6 of CGSC and 12 of CASC) only cause bitter rot, and four species (C. aenigma and C. asianum of CGSC, C. limetticola of CASC and C. karstii of CBSC) only cause GLS. These species were found to differ in their geographical distribution, environmental and host tissue preference, pathogenicity, and fungicide sensitivities. In this review, we summarize the distribution, life cycle, and pathogenicity mechanisms of all currently known Colletotrichum species responsible for bitter rot and GLS of apple. Furthermore, we describe known apple defense mechanisms and management strategies for the control of these economically significant pathogens and identify gaps in our present understanding for future research.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.