Geographical Origin Does Not Modulate Pathogenicity or Response to Climatic Variables of Fusarium oxysporum Associated with Vascular Wilt on Asparagus.

Alexandri María Brizuela,Justyna Lalak-Kańczugowska,Łukasz Stępień,Michał Kawaliło,Grzegorz Koczyk,Daniel Palmero

doi:10.3390/jof7121056

Abstract

Asparagus crop is distributed worldwide, covering very different climatic regions. Among the different diseases that affect asparagus, vascular Fusarium wilt, caused by Fusarium oxysporum f. sp. aparagi (Foa), stands out. It is not only the cause of large economic losses due to a decrease in yield and shortened longevity of the plantation, but also prevents replanting. This work aimed to determine if F. oxysporum isolates associated with vascular wilt on asparagus have adapted differentially to the different agro-environmental conditions. The potential correlation between origin and mycelial growth under different temperatures and humidity conditions was analysed for isolates from asparagus fields cultivated in northern and southern Europe. The genetic and pathogenic variability were also analysed. While a clear effect of water activity on mycelial growth was observed, all isolates responded in a similar way to changes in water activity in the medium, regardless of their geographical origin. The results revealed a low genetic variability of F. oxysporum isolates associated with vascular wilt on asparagus without signs of differentiation correlated to geographical origin. The southernmost isolates of the two cultivated varieties inoculated did not express more pathogenicity than those isolated from the colder region.

Highlights

Asparagus is the fourteenth largest open-field horticultural crop in the world, with more than 1.6 million hectares dedicated to it
The present study aimed to describe the possible adaptation of F. oxysporum isolates associated with vascular wilt on asparagus from two producing regions of Europe
Clade II consisted of five isolates of Fusarium oxysporum from Spain and three isolates from the Netherlands with strong bootstrap support of 84%

Summary

Introduction

Asparagus is the fourteenth largest open-field horticultural crop in the world, with more than 1.6 million hectares dedicated to it. Spain and Poland are the second and sixth largest asparagus producers in Europe, with 58,610 and 12,700 tons, respectively [1]. Among the key diseases affecting this crop, vascular wilting of asparagus stands out [4,5,6] worldwide. This disease, together with the appearance of root rot, causes what has been defined as Asparagus Decline Syndrome (ADS) [7], which is characterised by the significantly shortened longevity of the crop and a limiting factor in economic production

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