Identification of an A2 population of Phythophthora andina attacking tree tomato in Peru indicates a risk of sexual reproduction in this pathosystem

Abstract

Tree tomato, Solanum betaceum, is an Andean fruit crop previously shown to be attacked by Phytophthora andina in Ecuador and Colombia. Blight-like symptoms were discovered on tree tomato plants in the central highlands of Peru in 2003 and shown to be caused by P. andina. Isolates of P. andina, collected from three different plantations in Peru over a 6-year time span (2003)(2004)(2005)(2006)(2007)(2008), were compared genetically with P. andina isolates from Colombia and Ecuador to test whether the pathogen population is geographically structured in the Andes. Restriction fragment length polymorphism (RFLP), mitochondrial DNA and simple sequence repeat (SSR) genetic markers, and mating type behaviour indicated that the Peruvian P. andina population from tree tomato is genetically distinct from populations infecting tree tomato in Colombia (CO-1) and Ecuador (EC-3, Ia, A1), but is more similar to the population infecting solanaceous hosts of the Anarrhichomenum complex (EC-2, Ic, A2). Such geographic substructuring within this pathogen species could result from spatial isolation. Most strikingly, in contrast to the Ecuadorian and Colombian P. andina isolates from tree tomato, the Peruvian isolates have the A2 mating type. The presence of both mating types in the Andean population of P. andina attacking tree tomato indicates a risk of sexual reproduction and the presence of long-lasting oospores in this pathosystem.

Site‐specific distribution of oak rhizosphere‐associated oomycetes revealed by cytochrome c oxidase subunit II metabarcoding

“…The genus Phytophthora was represented by three different species: (a) P. cinnamomi , a widespread pathogen with a broad host range including Q. suber (Brasier et al, ; Scanu et al, ) and Q. ilex (Corcobado, Solla, Madeira, & Moreno, ), (b) a relative of P. quercina known as pathogen of various oak species including Q. ilex (Pérez‐Sierra et al, ) and Q. robur (Jung et al, ), and (c) P. andina , a sister lineage of P. infestans known to infect Solanaceae including tree tomato (Forbes, Gamboa, Lindqvist‐Kreuze, Oliva, & Perez, ) but also few other non‐Solanaceae hosts (Erwin & Ribeiro, ). Plant pathogens belonging to the Saprolegniales included relatives of Aphanomyces including the root pathogen A. euteiches (Cannesan et al, ).…”

The Importance of Mycological and Plant Herbaria in Tracking Plant Killers

“…P. andina (Adler et al, 2004;Oliva et al, 2010) is a close relative of P. infestans and hypothesized to have arisen through multiple hybridizations between P. infestans and an as yet undescribed species within Phytophthora clade 1c (Gomez-Alpizar et al, 2008;Goss et al, 2011;Blair et al, 2012;Lassiter et al, 2015). P. andina is a pathogen on various Solanum species in the Andean highlands and, in some South American locales, occurs sympatrically with P. infestans on Solanum betaceum (tree tomato) and Solanum muricatum (pear melón) (Perez et al, 2001;Adler et al, 2004;Oliva et al, 2010;Forbes et al, 2013Forbes et al, , 2016.…”

Ecological speciation within thePhytophthoragenus

“…It is important to mention that a group of strains referred to as P. andina (new lineage PE-8) has recently been reported as infecting S. betaceum in Peru (Forbes et al 2016). Further genetic, phylogenetic and population analyses and a greater number of isolates are needed to determine the identity, host range and fitness of isolates belonging to the PE-8 clonal lineage.…”

“…2010; Cárdenas et al 2012; Forbes ei al. 2013, 2016; Goss et al 2014; Lassiter et al 2015). To date, P. andina is composed of the nuclear lineages EC-2 with two mitochondrial lineages, Ia and Ic; and EC3 (with one mitochondrial haplotype, Ia) (Oliva et al 2010).…”