Genetic diversity in New Zealand populations ofSclerotium cepivorum

Abstract

Mycelial interactions were examined between 231 New Zealand isolates of Sclerotium cepivorum Berk., as well as 25 isolates from a further eight countries. Within the group of New Zealand isolates six mycelial compatibility groups (MCGs) were identified and named using reference strains obtained from the University of Guelph, Canada. Two new groups, presently only known from New Zealand, were identified. Heterogeneity was found both within and between fields in all regions. A subset of 51 S. cepivorum isolates was further investigated for genetic diversity using universally primed PCR (UP-PCR) and random amplified polymorphic DNA (RAPD) analyses. When results were analysed separately, each primer distinguished one to three genetic groups. However, when the results from two primers (L15 and OPAX15) were combined, six genetic groups were revealed. The results, as shown by MCGs and molecular methods, demonstrate the presence of genetic diversity in New Zealand field populations of S. cepivorum.H01 019

Molecular characterization of European and Egyptian isolates ofSclerotium cepivorum, the incitant of onion white rot

“…Based on the DNA band patterns, the tested isolates could be assigned to seven genetically different groups. Such results are in line with those reported by Couch and Kohn (2000), Patricia et al (2002), Tyson et al (2002) and Amin (2003). Data also indicate that there was no correlation between DNA patterns of S. cepivprum isolates and their virulence or culture origin.…”

“…Each sample was applied together with 5 ml ready loading buffer solution and 5 ml from 250 BP-Leiter as a marker (Roth) was used. Electrophoresis was performed at 100 V for 3.5 h. Then the gel was stained with ethidium bromide for 15 min and photographed under UV light (Tyson et al 2002).…”

“…Differentiation between such strains could be by means of electrophoretic and PCR analysis of esterase (Chen & Swart 2001;Cao & Ye 2001), presence of major proteins (Novak & Kohn 1988;Saeed & Abou-Elseoud 1990) and DNA fingerprints (Couch & Kohn 2000;Patricia et al 2002;Tyson et al 2002;Amin 2003).…”

Genetic and pathogenic diversity of Neofusicoccum parvum in New Zealand vineyards

“…The overlap between VCGs was unusual and may signify weak barriers to anastomosis and genetic exchange between isolates, thereby encouraging gene flow (Leslie 1993). Other researchers have reported weak barrage reactions in Magnaporthe grisea (Zeigler et al 1997) and Sclerotium cepivorum (Tyson et al 2002). In the case of M. grisea the authors showed evidence of parasexual recombination between isolates with weak barrage reactions.…”

Rapid and efficient extraction of genomic DNA from differentphytopathogenic fungi using DNAzol reagent

“…The DNAzol genomic DNA isolation reagent (DNAzol reagent) is a complete and ready-to-use reagent with a guanidine detergent lysing solution which hydrolyses RNA and allows the selective precipitation of DNA from a cell lysate (Chomezynski et al 1997). It has been employed for the isolation of genomic DNA from various biological materials including several fungal species (Czember & Arseniuk 1999, Hsiang & Mahuku 1999, Tyson et al 2002. Nevertheless, we found that the manufacturer's protocol could result in low DNA purity and yield from many species.…”