Population structure and migration of the Tobacco Blue Mold Pathogen, Peronospora tabacina, into North America and Europe

Abstract

Neutrality tests were significant and the equilibrium model of neutral evolution was rejected, indicating an excess of recent mutations or rare alleles. Hudson's S tests were performed to examine population subdivision and gene flow among populations. An isolation-with-migration analysis (IM) supported the hypothesis of long-distance migration of P. tabacina from the Caribbean region, Florida and Texas into other states in the United States. Within the European populations, the model documented migration from North Central Europe into western Europe and Lebanon, and migration from western Europe into Lebanon. The migration patterns observed support historical observations about the first disease introductions and movement in Europe. The models developed are applicable to other aerial dispersed emerging pathogens and document that high-evolutionary-risk plant pathogens can move over long distances to cause disease due to their large effective population size, population expansion and dispersal.

Deciphering the Bacillus amyloliquefaciens B9601-Y2 as a Potential Antagonist of Tobacco Leaf Mildew Pathogen During Flue-Curing

“…This crop is often used in cigarette blends or mixtures for pipe smoking and also a valuable medicinal plant as it has high alkaloid content. However, many post-harvest diseases such as frogeye leaf spot of tobacco (Dixon et al, 2018), blue mold (Blanco-Meneses et al, 2018), and tobacco soft rot (Wang R. et al, 2017) during production result in devastating losses. After harvesting from the field, leaves are stored for curing, redrying, aging, and fermentation, which negatively affect leaf carotenoids that slowly oxidize and importantly, cause degradation (Zhu et al, 2016;Popova et al, 2019).…”

Biological Characteristics and Assessment of Virulence Diversity in Pathosystems of Economically Important Biotrophic Oomycetes

“…The population structure and global migration pattern of blue mold were also characterized by sequencing two nuclear and one mitochondrial gene of 54 isolates of P. tabacina (Blanco-Meneses et al, 2018). These results supported the idea of long-distance migration of the pathogen from the Caribbean, Florida, and Texas to other northern US states.…”

Genetic diversity and population structure of Pepino mosaic virus in tomato crops of Spain and Morocco

“…Indeed, our neutrality tests showed negative values and deviated significantly from neutrality (Table ) with several sites in the TGB1 and CP genes under negative selection, which was consistent with the above genetic diversity results as well as the purifying selection identified in previous studies (Gómez et al, ). The negative values obtained for the PepMV population indicated an excess of single‐nucleotide variants with low frequency in the population (Blanco‐Meneses, Carbone, & Ristaino, ), and this could be suggesting that PepMV populations, in particular those of the CH2 strain, were in demographic expansion. Our results also showed frequent gene flow that contributes to genetically homogenise sub‐populations that are geographically close, revealing the importance of gene flow in shaping the genetic structure and evolutionary dynamics of PepMV.…”