Species-Specific Impact of Fusarium Infection on the Root and Shoot Characteristics of Asparagus

Soil-borne pathogens can have considerable detrimental effects on asparagus (Asparagus officinalis) growth and production, notably caused by theFusariumspeciesF. oxysporumf.sp.asparagi,F. proliferatumandF. redolens. In this study, their species-specific impact regarding disease severity and root morphological traits was analysed. Additionally, various isolates were characterised based on in vitro physiological activities and on protein extracts using matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS). The response of two asparagus cultivars to the differentFusariumspecies was evaluated by inoculating experiments. Differences in aggressiveness were observed betweenFusariumspecies and their isolates on roots, while no clear disease symptoms became visible in ferns eight weeks after inoculation.F. redolensisolates Fred1 and Fred2 were the most aggressive strains followed by the moderate aggressiveF. proliferatumand the less and almost non-aggressiveF. oxysporumisolates, based on the severity of disease symptoms. Fungal DNA in stem bases and a significant induction of pathogenesis-related gene expression was detectable in both asparagus cultivars. A significant negative impact of the pathogens on the root characteristics total root length, volume, and surface area was detected for each isolate tested, with Fred1 causing the strongest effects. No significant differences between the tested asparagus cultivars were observed.