Open AccessPathogenicity of Phytopythium chamaehyphon: A New Player in Kiwifruit Vine Decline Syndrome of Actinidia chinensis var. deliciosa ‘Hayward’ in Italy
Author(s) -
Francesco Savian,
Simona Prencipe,
Noemi Filippini,
L. Nari,
Marta Martini,
P. Ermacora,
D. Spadaro
Publication year - 2021
Publication title -
plant disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.663
H-Index - 108
eISSN - 1943-7692
pISSN - 0191-2917
DOI - 10.1094/pdis-01-21-0143-sc
Subject(s) - biology , actinidia deliciosa , actinidia , wilting , pathogenicity , vine , actinidia chinensis , botany , inoculation , root rot , waterlogging (archaeology) , horticulture , microbiology and biotechnology , ecology , wetland
Kiwifruit vine decline syndrome (KVDS) is a serious soil-borne disease that degrades the fine roots of both Actinidia chinensis var. deliciosa and var. chinensis. The disease seems to be the result of an interaction between several soil-borne pathogens, mostly oomycetes, and waterlogging. This work investigates the pathogenicity of the oomycete Phytopythium chamaehyphon recently isolated from roots of diseased plants. Pathogenicity was tested in 6-month-old and 1-year-old plants that, after inoculation, were flooded up to three times to induce symptom appearance. Leaf wilting and root rot typical of KVDS was observed in all the plants inoculated with P. chamaehyphon strain KD-15 (PCHA) and in all the positive controls potted in a mix of peat and soils collected in KVDS-affected orchards, while negative controls remained symptomless. Disease development on 6-month-old plants was characterized by unusual degradation of the not-lignified collar, occurring even in absence of flooding. Conversely, on 1-year-old plants, symptoms faithfully reproduced KVDS dynamics observed in orchard. This work confirmed the pathogenicity of P. chamaehyphon and raised new questions about the actual role of waterlogging in KVDS etiology.