Characterization of Isolates ofFusariumspp. Obtained from Asparagus in Spain

Abstract

Microbial analysis of asparagus plants (Asparagus officinalis) obtained from four nurseries in Spain in 2002 to 2003 indicated high frequencies of Fusarium proliferatum, F. oxysporum, and F. moniliforme in the rhizomes and storage roots. Out of 201 isolates of Fusarium obtained from nursery crowns and from plants sampled in nine established asparagus fields, the highest frequency of highly pathogenic isolates was observed from samples collected from fields, and included some extremely virulent isolates of F. solani. For isolates of low to moderate virulence, the percentage of those significantly (P = 0.01) associated with root dry weight loss was larger for F. proliferatum (53.8%) than for the other Fusarium species (10.3 to 23.1%). Random amplified polymorphic DNA (RAPD) analysis of 19 isolates of Fusarium spp. grouped all F. proliferatum and F. moniliforme isolates together and, in a second cluster, five of the eight isolates of F. oxysporum. Asparagus cultivars Verde-Morado and Dariana were the least susceptible of 11 cultivars commonly grown in Spain; isolates of F. solani and F. moniliforme proved highly virulent; and a significant interaction was observed among pathogen isolates and asparagus cultivars when representative pathogenic isolates of F. proliferatum, F. oxysporum, F. moniliforme, and F. solani were tested on those cultivars. Larger reductions in root dry weight were associated with F. proliferatum and F. solani than with F. oxysporum and F. moniliforme, and differences in root and stem dry weights among cultivars were significant.

Mycotoxins Biosynthesized by Plant-Derived Fusarium Isolates / Tvorba Mikotoksina U Vrstama Roda Fusarium Izoliranim Iz Biljaka

“…Nevertheless, even when they displayed moderate or low aggressiveness, they were still able to synthesize toxic metabolites inside plant tissues (3,13,46). In other studies, F. subglutinans (55) and F. ananatum (56) were identifi ed as the causes of fusariosis in pineapple, F. oxysporum and F. proliferatum (3,13,47,57) in asparagus, and F. oxysporum (58) in banana. Therefore, it is important to recognize the fungal species present inside the plant being investigated and also to evaluate the toxigenic potential of the potential plant pathogens.…”

Organic amendments conditions on the control of Fusarium crown and root rot of asparagus caused by three Fusarium spp.

“…F. oxysporum (Fo5), F. proliferatum (Fp3) and F. solani (Fs2), which had proven pathogenic to asparagus (Corpas-Hervias et al, 2006) were selected. Inocula of these isolates were obtained by incubation of flasks with sterile potato-dextrose broth (PDB) to which four actively growing mycelium disks on potato dextrose agar (PDA) plates per flask were added.…”

“…This disease is difficult to control due to, among other factors, the long-term survival of the pathogen in the soil and its easy propagation by planting material (Elmer, 2001;Corpas-Hervias et al, 2006). Furthermore, chemical treatments are frequently ineffective or provide short-term protection (Elmer, 2001).…”

Management of Fusarium crown and root rot of asparagus

“…Over time, new species of Fusarium were shown to be causal to the disease and could incite the same symptoms. Fusarium proliferatum (syn Fusarium moniliforme) was reported in 1979 (Johnston et al, 1979), F. redolens, a sister species of F. oxysporum was reported in 2000 (Baayen et al, 2000b), and Fusarium solani in 2006 (Corpas-Hervias et al, 2006). In most regions, F. oxysporum f. sp.…”

“…asparagi and F. proliferatum tend to dominate the species complex on asparagus (Elmer, 1997). However, in Europe, pathogenic isolates of Fusarium redolens and F. solani are found to be more prevalent (Baayen et al, 2000b;Corpas-Hervias et al, 2006). Molecular genotyping has shown F. oxysporum f. sp.…”