PCR-SSCP analysis of Fusarium diversity in asparagus decline in Japan

Abstract

The diversity of Fusarium populations in asparagus (Asparagus officinalis L.) decline fields in Japan was estimated by PCR-SSCP (single-stranded conformational polymorphism) analysis of the ITS2 regions of the nuclear rRNA genes. This method was used to rapidly and objectively identify pathogens associated with roots of plants showing symptoms of asparagus decline collected from fields in five regions across Japan. Over 651 fusarial isolates were obtained, and were easily differentiated into three principal species. Fusarium oxysporum f. sp. asparagi was most frequently isolated from the domestic five regions (68%), whereas Fusarium proliferatum (28.6%) was less frequent. Fusarium solani was found much rarely (2.5%). The frequency of isolation of Fusarium proliferatum increased gradually from the north to the south of Japan, though considerable differences were found between fields in each region, as well as regional differences among the Fusarium populations. Most of the fusarial isolates were highly pathogenic in vitro. These results reveal that Fusarium oxysporum f. sp. asparagi and Fusarium proliferatum are important biotic factors which lead to asparagus decline in Japan.

Phenotypic and phylogenetic segregation of Alternaria infectoria from small-spored Alternaria species isolated from wheat in Germany and Russia

“…The epidemiology of other toxigenic fungi like Fusarium spp. is well investigated to assess spatial and temporal distribution of these economically important phytopathogens (Bentley et al 2008;Nahiyan et al 2011;Beyer et al 2014) and other fungal genera (Lumbsch et al 2008;€ Opik et al 2013). Pasquali and Migheli (2014) summarized the persistence and spread of Fusarium chemotypes worldwide and demonstrated regional differences, spatial chemotype diversity and the influence of environmental and cultural practices.…”

Suppression of Fusarium Crown Rot and Increase in Several Free Amino Acids in Mycorrhizal Asparagus

“…[1,2,8]. In Japan, Nahiyan et al [9] demonstrated that Fp and Foa are dominant Fusarium species in asparagus decline fields by PCR-SSCP analysis. However, the diseases are still difficult to control because no resistant cultivar or disinfesting method has been developed.…”

Tolerance to Fusarium Root Rot and Changes in Antioxidative Ability in Mycorrhizal Asparagus Plants

“…The problem is exacerbated by a replant phenomenon such that additional loss is incurred if fields are replanted with asparagus (Blok and Bollen, 1995). A number of facts worldwide contribute to asparagus decline, but the most significant is crown and root rot caused by Foa and Fusarium proliferatum (Elmer et al, 1996;Knaflewski et al, 2008;Nahiyan et al, 2011;Reid et al, 2002;Wong and Jeffries, 2006). In addition, abiotic factors such as allelopathic residues can increase plant stress and accelerate the decline phenomenon (Lake et al, 1993;Miller et al, 1991;Yong, 1984).…”