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First report of leaf and twig blight of Indian hawthorn (Rhaphiolepis indica) caused by Neofusicoccum parvum in Italy

  • Giorgio GusellaEmail author
  • Dalia Aiello
  • Giancarlo Polizzi
Disease Note
  • 159 Downloads

Keywords

Botryosphaeriaceae Leaf Blight Neofusicoccum parvum Rhaphiolepis indica 

During the winter of 2018 symptoms of leaf and twig blight were observed on about 15% of 7500 4-year-old potted plants of Indian hawthorn [Rhaphiolepis indica (L.) Lindl.] grown in a commercial nursery in Catania province, Italy.

Necrosis was found in the petioles, moving upward through the mid rib and blade, showing brownish V-shape lesion at the bottom of the leaves and leading to a complete blight of the twigs. Under the bark, discolored tissue was found. Diseased tissues were surface disinfected for 1 min in 1.5% sodium hypochlorite solution, rinsed in sterile water, placed on PDA amended with 100 mg/l of streptomycin sulfate, and then incubated at 25 °C for seven days. A fungus like Neofusicoccum sp. was consistently isolated. ITS region of rDNA and part of tef1 gene were amplified using ITS5, ITS4 and EF1-728F, EF1-986R primers, respectively. The sequence data were deposited in GenBank. BLAST analysis identified the fungus as Neofusicoccum parvum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips. The obtained ITS sequences (GenBank accession Nos. MN128645; MN128646) of the isolates CBS 145794, CBS 145795 showed 99.65% and 99.83% identity with the tester isolate (KJ657701) respectively, and tef sequences (MN175951; MN175952) showed 100% and 98.97% (KJ126847). The isolates have been registered in the CBS Westerdijk Fungal Biodiversity Institute collection (Utrecht). Pathogenicity tests were conducted inoculating 10 twigs with a mycelial plug. Control consisted of sterile PDA plugs. Plants were moved into a growth chamber at 25 °C ± 1 °C. The same symptoms observed in field appeared on 90% of the inoculated twigs after 10 days and complete twigs blight of the apical part of the plant after 17 days. Re-isolations completed Koch’s postulates. This fungus is spreading in Sicily on different important crops (Guarnaccia et al. 2016; Ismail et al. 2013) but for our knowledge, this is the first report of leaf and twig blight caused by N. parvum on Indian hawthorn.

Notes

References

  1. Guarnaccia V, Vitale A, Cirvilleri G, Aiello D, Susca A, Epifani F, Perrone G, Polizzi G (2016) Characterisation and pathogenicity of fungal species associated with branch cankers and stem-end rot of avocado in Italy. Eur J Plant Pathol 146(4):963–976CrossRefGoogle Scholar
  2. Ismail AM, Cirvilleri G, Lombard L, Crous PW, Groenewald JZ, Polizzi G (2013) Characterisation of Neofusicoccum species causing mango dieback in Italy. J Plant Pathol 95(3):549–557Google Scholar

Copyright information

© Società Italiana di Patologia Vegetale (S.I.Pa.V.) 2019

Authors and Affiliations

  1. 1.Dipartimento di Agricoltura, Alimentazione e Ambiente, sezione Patologia VegetaleUniversity of CataniaCataniaItaly

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