Studies on the Identification of Resistance to Fusarium oxysporum (Schlecht.) in Different Genetic Backgrounds of Asparagus officinalis (L.) and Its Defense Responses

Due to the restricted genetic diversity among current asparagus cultivars, wild relatives are of particular interest as a source of resistance. In this study, seventeen cultivars and wild relatives were tested for their resistance to Fusarium oxysporum in the seedling test. Two isolates differing in virulence (single spore lines with high and low virulence) were used for testing. Most of the tested genotypes showed high infestation, whereby Asparagus aethiopicus caused no browning of the roots or growth depression. This wild relative was evaluated for its defence response after infection with F. oxysporum. For comparison, the wild relative Asparagus densiflorus and Asparagus officinalis cv. Thielim were tested. Like A. densiflorus, A. aethiopicus showed accumulation of hydrogen peroxide as a defence mechanism, while Asparagus officinalis cv. Thielim showed no storage of hydrogen compounds.