A robust hydroponic-based system for screening red clover (Trifoliorum pratense) for Fusarium avenaceum

Abstract

AbstractBackgroundRed clover (Trifolium pratense) is an important forage legume crop that suffers like most perennial crops from attacks by soilborne pathogens.Fusariumroot rot is one of the most serious diseases and at the same time problematic to identify resistance to due to its hidden life in the soil. Current screening methods are laborious and hampered by limited reproducibility. To remedy this situation, we aimed to establish a more undemanding and reliable system to facilitate studies of red clover-Fusarium avenaceuminteractions.ResultsFirst, the fungal spore concentrations were balanced toward the development of red clover plants grown hydroponically. We found that the optimum concentration was 30,000 spores in 2 L of hydroponic medium to ensure infection during the plant growth period in this system. The procedure was scaled-up to screen twenty-five populations to identify red clover genotypes with the most contrasting responses toF. avenaceum.Susceptible plants had approximately 2-fold higher amounts of fungal DNA than resistant plants, demonstrating a correlation between the disease readings of the plants and pathogen DNA.ConclusionsA hydroponics-based screening system was established to facilitate reproducible and rapid screening ofFusariumroot rot disease in red clover. We foresee this screening procedure meeting the needs of both applied breeding work and in-depth molecular studies of responses between this pathogen and its host plant. This method could be applied for the screening of other plant species for resistance toFusariumspp. or to other root microbes.