SSR marker analysis of Monilinia fructicola from Swiss apricots suggests introduction of the pathogen from neighbouring countries and the United States

Abstract

Monilinia fructicola is a quarantine fungal pathogen in Europe, but many major stone fruit growing countries in Europe have reported its presence recently. In Switzerland, the fungus was first found in a single apricot orchard in 2008. This study confirms the presence of M. fructicola in nine out of 22 commercial orchards in Canton Valais, Switzerland. Five simple sequence repeat markers (SSRs) were developed for M. fructicola and samples from Switzerland, Spain, Italy, France and the United States were analysed and compared in order to assess the genetic diversity of the pathogen, identify the origin of the disease, and verify if the fungus reproduces sexually in Europe. In the 119 European samples analysed, 12 different haplotypes were found, indicating a relatively high genetic diversity of the pathogen considering that the first report in Europe was 10 years ago. Three haplotypes found in Europe were identical to those found in the American samples (two from the east coast and one from the west coast). Population structure analysis suggests that the European population is derived from at least two ‘invasion’ events probably originating from the US (one from the east coast, the other from the west coast). Preliminary evidence of sexual reproduction of M. fructicola in Europe is reported.

Identification and variability of Monilinia spp. isolates from peach

“…Villarino et al (2012) found genetic differences among isolates of M. fructicola from French and Spanish orchards. Similar result was also reported by Jänsch et al (2012) with M. fructicola isolates from the United States and Europe. For these authors, the variability among isolates may have occurred due to sexual reproduction, accumulation of random mutations or through gene flow.…”

Peach Brown Rot: Still in Search of an Ideal Management Option

“…Hence, Monilinia isolates could be grown on PDA Petri dishes directly from infected organs, i.e., fruits, mummies, twigs [193], or already prepared cultures. In addition, there are numerous methodologies describing partially similar, and in some cases divergent, protocols concerning spores concentration, inoculum load, and associated variables for screening BR susceptibility in stone fruits, peach and nectarine in particular.…”

Identification of SNPs linked to eight apple disease resistance loci

“…The sequences of the flanking markers were blasted against the 'Golden Delicious' genomic sequence (Velasco et al 2010) using BLAST (Altschul et al 1990), and SSR repeats were identified using the microsatellite finder webtool ''YourLabData'' (2011). SSR-specific primers were designed using the Primer 3 webtool v.0.4.0 (Rozen and Skaletsky 2000), labeled primers were purchased from Microsynth AG (Balgach, Switzerland), and the SSR marker analysis conducted according to Jänsch et al (2012). The parents of the cross and a total of 10-25 resistant and susceptible progeny plants as well as recombinants around the resistance locus (4-11 genotypes) were screened to identify and map the SSR markers that were polymorphic in the resistant parent.…”