Pathogenic variation and molecular characterization of Fusarium species isolated from wilted Welsh onion in Japan

Abstract

Thirty-two isolates of Fusarium species were obtained from wilted Welsh onion (Allium fistulosum) grown on nine farms from six regions in Japan and identified as F. oxysporum (18 isolates), F. verticillioides (7 isolates), and F. solani (7 isolates). The pathogenicity of 32 isolates was tested on five commercial cultivars of Welsh onion and two cultivars of bulb onion in a seedling assay in a greenhouse. The Fusarium isolates varied in the degree of disease severity on the cultivars. Five F. oxysporum isolates (08, 15, 17, 22, and 30) had a higher virulence on the cultivars than the other isolates. The host range of these five isolates was limited to Allium species. Molecular characterization of Fusarium isolates was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the internal transcribed spacer (ITS) regions of ribosomal DNA. The 32 isolates were grouped into eight types (four types for F. oxysporum, one for F. verticillioides, and three for F. solani). Restriction patterns of the ITS region were not related to pathogenicity. However, the haplotypes obtained with five enzymes (RsaI, HinfI, HaeIII, ScrFI, and MspI) and the phylogenetic analysis permitted the discernment of the three Fusarium species. The PCR-RFLP analysis should provide a rapid, simple method for differentiating Fusaruim species isolated from wilted Welsh onion in Japan.

Black Aspergilli and fumonisin contamination in onions purchased in Hungary

“…These isomers were found to be produced by A. awamori in a previous study . Previously another fumonisin producing fungus, Fusarium proliferatum has also been found to be able to infect onion bulbs (Dissanayake et al 2009a(Dissanayake et al , 2009bDu Toit et al 2003;Galvan et al 2008;Stankovic et al 2007). However, this species was not identified in any of the onion samples examined in this study (data not shown).…”

A Comparative Study on the Total Antioxidant and Antimicrobial Potentials of Ethanolic Extracts from Various Organ Tissues of <i>Allium</i> spp.

“…Traditionally, they also play a very essential role in the daily diet in many Asia countries, and many used to flavor foods. The green onions (Allium fistulosum L.), also referred to as the Welsh onion, and garlic (Allium sativum L.) belong to the family Alliaceae, which are very economically important vegetables in most East Asian countries [1][2][3]. The Allium spp.…”

“…Antioxidant and antimicrobial effects of Allium plants have been reported for times [1,4,5,10]; however, a study on the top-quality green onions and garlic produced in Taiwan is still scarce. In this study, different types of tissue of Taiwan Sun-Shin green onion and garlic were extracted from roots, stems and leaves using ethanol.…”

Genetic diversity and population structure of Fusarium oxysporum f. sp. cepae, the causal agent of fusarium basal plate rot on onion, using RAPD markers

“…However, RAPD analysis did not reveal a relationship between genetic and pathogenic variability of Turkish isolates. Similarly, Dissanayake et al (2009) separated F. oxysporum isolates obtained from Welsh onion into two genetic groups with 61.6% similarity, but not detected clear-cut relationship between clustering in the PCR-RFLP dendrogram and pathogenicity test. These results were in agreement with the previous studies which fail to provide a relationship between RAPD data and pathogenic groups of Fusarium oxysporum (Hernandez et al 1999;Freeman & Maymon 2000;Cramer et al 2003).…”

“…Different methods have been used to assess genetic variation within populations of F. oxysporum f. sp. cepae such as Vegetative Compatibility Grouping (VCGs), Amplified Fragment Length Polymorphisms (AFLPs), Restriction Fragment Length Polymorphism (RFLP) analysis of Internal Transcribed Spacer (ITS) and Intergenic Spacer (IGS) regions of rDNA (Swift et al 2002, Galván et al 2008Dissanayake et al 2009, Bayraktar et al 2010. These studies have revealed that F. oxysporum f. sp.…”