Genetic Diversity and Fitness of Fusarium graminearum Populations from Rice in Korea

Abstract

Fusarium graminearum is an important fungal pathogen of cereal crops and produces mycotoxins, such as the trichothecenes nivalenol and deoxynivalenol. This species may be subdivided into a series of genetic lineages or phylogenetic species. We identified strains of F. graminearum from the Republic of Korea to lineage, tested their ability to produce nivalenol and deoxynivalenol, and determined the genetic composition and structure of the populations from which they were recovered. Based on amplified fragment length polymorphism (AFLP), PCR genotyping, and chemical analyses of trichothecenes, all 249 isolates from southern provinces belonged to lineage 6, with 241 having the nivalenol genotype and 8 having the deoxynivalenol genotype. In the eastern Korea province, we recovered 84 lineage 6 isolates with the nivalenol genotype and 23 lineage 7 isolates with the deoxynivalenol genotype. Among 333 lineage 6 isolates, 36% of the AFLP bands were polymorphic, and there were 270 multilocus haplotypes. Genetic identity among populations was high (>0.972), and genotype diversity was low (30 to 58%). To test the adaptation of lineage 6 to rice, conidial mixtures of strains from lineages 3, 6, and 7 were inoculated onto rice plants and then recovered from the rice grains produced. Strains representing lineages 6 and 7 were recovered from inoculated spikelets at similar frequencies that were much higher than those for the strain representing lineage 3. Abundant perithecia were produced on rice straw, and 247 single-ascospore isolates were recovered from 247 perithecia. Perithecia representing lineage 6 (87%) were the most common, followed by those representing lineage 7 (13%), with perithecia representing lineage 3 not detected. These results suggest that F. graminearum lineage 6 may have a host preference for rice and that it may be more fit in a rice agroecosystem than are the other lineages present in Korea.

Genetic and phenotypic diversity within the Fusarium graminearum species complex in Norway

“…While the species within the FGSC show a significant biogeographic structure (Aoki et al 2012), substantial species diversity has been observed in South America (Scoz et al 2009;Sampietro et al 2010;Umpiérrez-Failache et al 2013), Asia (Yli-Mattila et al 2009Suga et al 2008;Zhang et al 2012), Africa (Boutigny et al 2011;O'Donnell et al 2008) and New Zealand (Monds et al 2005). Long-distance dispersal and anthropogenic activities have the potential to alter regional pathogen composition as suggested by the recent discovery of significant populations of F. asiaticum, an Asian endemic that appears to be adapted to rice agroecosystems (Lee et al 2009), on wheat in major rice production areas of Louisiana and Uruguay . However, climatic conditions in Norway and other parts of Northern Europe may create a barrier to the establishment of some FGSC species.…”

Difference in Chemotype Composition of Fusarium graminearum Populations Isolated from Durum Wheat in Adjacent Areas Separated by the Apennines in Northern-Central Italy

“…In our experiment this could be explained with two hypothesis: first, F. graminearum NIV chemotype, mentioned by Zhang et al (2007), is in lineage 6, so in some way they may behave differently from F. graminearum population of NorthernCentral Italy (lineage 7), exclusively isolated from durum wheat. On rice Lee et al (2009), observed that the different ecological ability between lineage 6 isolates and lineage 7 isolates were not directly related to the mechanism of pathogenicity; second, it is possible that some chemotypes of F. graminearum could be transported to other locations by seed shipping and long-distance spore transportation influencing chemotype composition (Guo et al, 2008). In fact in Western Canada, between 1998 and 2004, it was detected an increase of more than 14-fold of F. graminearum 3Ac-DON producers: that was linked to an introduction of a 3Ac-DON pathogenic population that was more toxigenic and vigorous, with a selective advantage above 15Ac-DON chemotype (Ward et al, 2008).…”

Detection of nivalenol and deoxynivalenol chemotypes produced by Fusarium graminearum species complex isolated from barley in Iran using specific PCR assays

“…Fusarium culmorum, F. poae, and F. avenaceum are observed in many European countries while F. asiaticum is observed in Asia (Waalwijk et al 2003). Fusarium graminearum and F. asiaticum, members of theet al 2014), whereas F. asiaticum is the major agent of FHB in many Asian countries such as China, Korea, Japan and Nepal (Zhang et al 2007;Karugia et al 2009;Lee et al 2009;Sarver et al 2011). FGSC possesses extremely important species which are very widespread.…”