Abstract
BackgroundPhytophthora infestans (Mont.) de Bary, the causal agent of potato late blight, is responsible for tremendous crop losses worldwide. Countries in the northern part of the Andes dedicate a large proportion of the highlands to the production of potato, and more recently, solanaceous fruits such as cape gooseberry (Physalis peruviana) and tree tomato (Solanum betaceum), all of which are hosts of this oomycete. In the Andean region, P. infestans populations have been well characterized in Ecuador and Peru, but are poorly understood in Colombia and Venezuela. To understand the P. infestans population structure in the Northern part of the Andes, four nuclear regions (ITS, Ras, β-tubulin and Avr3a) and one mitochondrial (Cox1) region were analyzed in isolates of P. infestans sampled from different hosts in Colombia and Venezuela.ResultsLow genetic diversity was found within this sample of P. infestans isolates from crops within several regions of Colombia and Venezuela, revealing the presence of clonal populations of the pathogen in this region. We detected low frequency heterozygotes, and their distribution patterns might be a consequence of a high migration rate among populations with poor effective gene flow. Consistent genetic differentiation exists among isolates from different regions.ConclusionsThe results here suggest that in the Northern Andean region P. infestans is a clonal population with some within-clone variation. P. infestans populations in Venezuela reflect historic isolation that is being reinforced by a recent self-sufficiency of potato seeds. In summary, the P. infestans population is mainly shaped by migration and probably by the appearance of variants of key effectors such as Avr3a.
Highlights
Phytophthora infestans (Mont.) de Bary, the causal agent of potato late blight, is responsible for tremendous crop losses worldwide
Each P. infestans clonal lineage is associated with a different host group: US-1 lineage with tomato, EC-1 with potato, EC-2 with wild solanaceous species, with the Anarrhichomenum section, and EC-3 with S. betaceum [15,16,17]
Genetic differentiation is found among isolates of P. infestans associated with S. ochranthum [18]
Summary
Phytophthora infestans (Mont.) de Bary, the causal agent of potato late blight, is responsible for tremendous crop losses worldwide. The potato and tomato late blight pathogen, Phytophthora infestans (Mont.) de Bary [1], has a broad host range within the Solanaceae family including Solanum phureja (yellow potato), S. betaceum (tree tomato), S. quitoense (naranjilla or lulo), Physalis peruviana (cape gooseberry), and other wild species [2,3]. Mitochondrial and nuclear DNA regions of P. infestans have been extensively used in different regions of Population studies of P. infestans in the Andean region have been focused on Peru and Ecuador. These two countries are considered to be the center of origin of potatoes, [14] and some authors have proposed that this region is the center of origin of the P. infestans pathogen [8,9]. A new mitochondrial haplotype, Ic, has been related to lineage EC-2, and has been correlated with a new species, P. andina [8,23]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
