Twig and Shoot Dieback of Citrus, a New Disease Caused by Colletotrichum Species

Abstract

(1) Background: This study was aimed at identifying the Colletotrichum species associated with twig and shoot dieback of citrus, a new syndrome occurring in the Mediterranean region and also reported as emerging in California. (2) Methods: Overall, 119 Colletotrichum isolates were characterized. They were recovered from symptomatic trees of sweet orange, mandarin and mandarin-like fruits during a survey of citrus groves in Albania and Sicily (southern Italy). (3) Results: The isolates were grouped into two distinct morphotypes. The grouping of isolates was supported by phylogenetic sequence analysis of two genetic markers, the internal transcribed spacer regions of rDNA (ITS) and β-tubulin (TUB2). The groups were identified as Colletotrichum gloeosporioides and C. karstii, respectively. The former accounted for more than 91% of isolates, while the latter was retrieved only occasionally in Sicily. Both species induced symptoms on artificially wound inoculated twigs. C. gloeosporioides was more aggressive than of C. karstii. Winds and prolonged drought were the factor predisposing to Colletotrichum twig and shoot dieback. (4) Conclusions: This is the first report of C. gloeosporioides and C. karstii as causal agents of twig and shoot dieback disease in the Mediterranean region and the first report of C. gloeosporioides as a citrus pathogen in Albania.

Inhibitory Activity of Shrimp Waste Extracts on Fungal and Oomycete Plant Pathogens

“…However, many copper-based treatments are not cost effective in commercial lemon groves, and also represent a significant source of environmental pollution [53]. Another copper-susceptible pathogen is C. gloeosporioides, the causative agent of anthracnoses in several fruits and vegetables [54] as well as of twig and shoot dieback in citruses [55]. Phytophthora nicotianae is very likely the most widespread and destructive Phytophthora species worldwide, affecting a very wide host range of more than 255 plant species [8,56,57].…”

“…Fungal and oomycete strains were included in this study. Most of them had been previously characterized [7,8,55,79,80]. The complete list of strains tested in this study is as follows: four Penicillium spp.…”

Morphology, Phylogeny and Pathogenicity of Colletotrichum menglaense sp. nov., Isolated from Air in China

“…For example, C. karstiiwas was reported from diseased black plum (Diospyros australis), strawberry (Fragaria xananassa), and banana (Musa nana Lour). C. gloeosporioides species complex organisms were also frequently isolated from a variety of hosts, including kumquat, finger lime, grapefruit, lemon, lime, mandarin, orange, and Persian lime [37,56].…”

“…Species of Colletotrichum are occasionally found as saprobes [34,35]. Some species were also isolated simultaneously as an endophyte, pathogen, and saprobe [36,37]. As for Colletotrichum spp.…”

Transcriptome Analysis of Colletotrichum fructicola Infecting Camellia oleifera Indicates That Two Distinct Geographical Fungi Groups Have Different Destructive Proliferation Capacities Related to Purine Metabolism

“…Colletotrichum species are globally distributed plant pathogens of many herbaceous and tree crops [4][5][6][7][8][9][10][11][12][13]. They are hemibiotrophic plant fungi and can affect almost all crops and economic plants.…”