Population genetic structure of Microdochium majus and Microdochium nivale associated with Fusarium head blight of wheat in Hokkaido, Japan

Abstract

Microdochium majus and Microdochium nivale are two of fungal pathogens that cause Fusarium head blight (FHB) in wheat, and have also caused pink snow mold in eastern Hokkaido, Japan. With the aim of assessing levels of genetic variation and population structure, 172 isolates of these Microdochium species obtained from five populations of infected wheat seeds were first classified into each species using polymerase chain reaction (PCR) amplification with specific primers. In total 165 (95.9 % of all isolates) and seven isolates (six of Tokachi populations and one of Abashiri populations) were identified as M. majus and M. nivale, respectively, indicating that M. majus was predominant and the main causal pathogen of FHB in this area. Inter-simple sequence repeat (ISSR) analysis showed that the total genetic diversity was 0.023 when estimated by Nei's gene diversity index within the five populations dominated by M. majus. An AMOVA analysis also showed that 86.74 % of the total genetic variation was within populations and 13.26 % among populations. These results indicated that little genetic differentiation occurred among the five populations of M. majus. Based on the unweighted pair group method of cluster analysis using the ISSR data, all isolates were identified as one of eight haplotypes in M. majus or six haplotypes in M. nivale, allowing the construction of a dendrogram with two clades corresponding to each species. There was no correlation between the clustering of isolates and their geographic distribution on the tree. These findings show that migration is likely playing an important role in the population biology of M. majus, providing some support for the prediction of epidemics of fungicide resistant strains within populations of the FHB pathogen

Snow mold of winter cereals: a complex disease and a challenge for resistance breeding

“…Glynn & S.G. Edwards (Glynn et al 2005 ; Watanabe et al 2011 ; Hayashi et al 2014 ). M. nivale and M. majus can be differentiated by morphological means (Gerlach and Nirenberg 1982 ; Lees et al 1995 ; Hernández-Restrepo et al 2016 ), quantitative real-time PCR (Nielsen et al 2013 ; Sonia et al 2018 ), molecular markers (Hayashi et al 2014 ; Matušinsky et al 2019 ), and gene-sequence analyses (Einax and Voigt 2003 ; Jewell and Hsiang 2013 ). Very recently, Abdelhalim et al ( 2020 ) demonstrated that M. nivale isolates revealed genetic differences related to different host plants (grasses vs .…”

Phylogenetic analysis of Microdochium spp. associated with turfgrass and their pathogenicity in cereals

“…These fungi cause economic losses in wheat and barley ( Tronsmo et al, 2001 ; Abdallah-Nekache et al, 2019 ; Mao et al, 2023 ). These two agents also cause head blight, which is frequently observed in wheat ( Kammoun et al, 2009 ; Pancaldi et al, 2010 ; Hayashi et al, 2014 ). In a study conducted in Morocco, it was reported that wheat grains were highly contaminated with M. majus ( Saoudi et al, 2019 ).…”

Rye Snow Mold-Associated Microdochium nivale Strains Inhabiting a Common Area: Variability in Genetics, Morphotype, Extracellular Enzymatic Activities, and Virulence

“…Irrespective of their original host, M. nivale sensu stricto and M. majus display differential virulence toward their hosts [52]. M. nivale sensu stricto (that is known to be characterized by high genetic diversity in contrast to M. majus [46,51]) was shown to have genetic differences related to different host plants (grasses and cereals) [25] and different turf grass species [53].…”