Phylogeography of the wide‐host range panglobal plant pathogen Phytophthora cinnamomi

Abstract

Various hypotheses have been proposed regarding the origin of the plant pathogen Phytophthora cinnamomi. P. cinnamomi is a devastating, highly invasive soilborne pathogen associated with epidemics of agricultural, horticultural and forest plantations and native ecosystems worldwide. We conducted a phylogeographic analysis of populations of this pathogen sampled in Asia, Australia, Europe, southern and northern Africa, South America, and North America. Based on genotyping-by-sequencing, we observed the highest genotypic diversity in Taiwan and Vietnam, followed by Australia and South Africa. Mating type ratios were in equal proportions in Asia as expected for a sexual population. Simulations based on the index of association suggest a partially sexual, semi-clonal mode of reproduction for the Taiwanese and Vietnamese populations while populations outside of Asia are clonal. Ancestral area reconstruction provides new evidence supporting Taiwan as the ancestral area, given our sample, | 5165 SHAKYA et Al.

Whole-genome single nucleotide polymorphism analysis for typing the pandemic pathogen Fusarium graminearum sensu stricto

“…To minimize the impact of geographic variation that may interfere with the results, we incorporated a large set of geographically diverse strains. Such a strategy is especially critical for pandemic species, which are often subdivided into genetically distinct populations ( Shakya et al, 2021 ). F. graminearum formed a peripheral clade on the tree separating the species into thirteen major subclades named I to XIII.…”

Differences in the Proteomic and Metabolomic Response of Quercus suber and Quercus variabilis During the Early Stages of Phytophthora cinnamomi Infection

“…This correlation between the variation in Phytophthora content, estimated either through qPCR-based or peptide-based approaches, and host susceptibility to the pathogen has been reported by previous studies ( Vandemark and Barker, 2003 ; Catal et al, 2013 ; Dufková et al, 2021 ). The apparent difference in susceptibility between Quercus species might be attributed to the presumed area of origin of P. cinnamomi in south-east Asia ( Jung et al, 2020 ; Shakya et al, 2021 ), which coincides with that of Q. variabilis ( Wang et al, 2016 ) and might have allowed certain degree of co-evolution between host and pathogen ( Jung et al, 2017 , 2018 , 2020 ). In fact, it has been reported how trees in native Q, variabilis forests in Taiwan appeared generally healthy, despite the presence of P. cinnamomi ( Jung et al, 2017 ).…”

“…Cork oaks are susceptible to the attack of Phytophthora cinnamomi Rands, arguably the most cosmopolite and polyphagous pathogen of woody plants and other host species ( Jung et al, 2013 ; Hardham and Blackman, 2018 ). While its center of origin has recently been demonstrated to be Southeast Asia ( Shakya et al, 2021 ), the presence of disease symptoms typical of P. cinnamomi infections has been reported in Europe as early as the XIX century ( Bergot et al, 2004 ). This pathogen has been demonstrated as main causal agent of the severe decline of Q. suber in Spain, Portugal and Italy ( Robin et al, 1998 ; Camilo-Alves et al, 2013 ; Scanu et al, 2013 ; Moricca et al, 2016 ; Avila et al, 2017 ; Jung et al, 2018 ; Seddaiu et al, 2020 ; Cardillo et al, 2021 ).…”

Phytophthora heterospora sp. nov., a New Pseudoconidia-Producing Sister Species of P. palmivora

“…heterocystica was originally described, supports the hypothesis of a West African origin [ 1 , 14 ]. However, to ascertain the evolutionary and geographic origin of P. heterospora , further studies are needed, including surveys in yet non-surveyed natural environments to detect the pathogen on co-evolved hosts without causing diseases [ 69 , 70 ], followed by phenotyping and genotyping studies using a global population [ 71 , 72 , 73 ].…”