Pathogenicity of Ilyonectria liriodendri and Dactylonectria macrodidyma propagules in grapevines

Autor: Hayley J. Ridgway, Chantal M. Probst, E. Eirian Jones, Marlene V. Jaspers
Rok vydání: 2019
Předmět:
Zdroj: European Journal of Plant Pathology. 154:405-421
ISSN: 1573-8469
0929-1873
DOI: 10.1007/s10658-018-01664-0
Popis: Black foot disease, caused by Ilyonectria liriodendri and Dactylonectria macrodidyma, is a significant disease of grapevines both in New Zealand and worldwide. The aim of this study was to determine the pathogenicity of New Zealand I. liriodendri and D. macrodidyma isolates in two grapevine rootstocks as callused and rooted propagation material. Three isolates each of I. liriodendri and D. macrodidyma, all infected callused and root-wounded grapevine rootstock plants (varieties ‘101–14’ and ‘5C’). Isolates from each species caused high disease incidences and severities at both 1 and 5 cm above the stem base. There were no significant differences in disease incidence or severity between rootstocks ‘101–14’ and ‘5C’. However, vines arising from callused rootstock had significantly higher disease incidence and severity compared with rooted vines. Conidia caused greater disease incidence and severity compared with chlamydospores and mycelium. A novel threshold propagule experiment with I. liriodendri propagules determined that disease incidence and severity at the stem base were significantly affected by the concentration of the propagules rather than the propagule type. Root dry weights significantly differed between I. liriodendri and D. macrodidyma isolates but not between species. Root dry weights were higher with callused versus rooted vines, with mycelium versus chlamydospores or conidia, and with propagule concentration rather than propagule type. Shoot dry weights were significantly higher for I. liriodendri compared with D. macrodidyma species, rooted versus callused vines and ‘101–14’ compared with ‘5C’ rootstocks. The results of the study has confirmed that both I. liriodendri and D. macrodidyma were capable of infecting grapevines through wounded roots or callused basal ends, indicating that these pathogens are capable of invading grapevines either in nurseries or in vineyards.
Databáze: OpenAIRE
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