RESUMEN
Mitochondrial DNA (mtDNA) haplotypes were determined using restriction fragment length polymorphism (RFLP) for P. infestans sampled from 513 foliar lesions of late blight found on potato and tomato in different regions of Ethiopia. Among the four reported mitochondrial haplotypes of Phytophthora infestans, Ia, Ib and IIb were detected in 93 % of the samples analyzed but the vast majority of these were Ia. The remaining 7 % represented a previously unreported haplotype. DNA sequencing of this new haplotype also confirmed a single base nucleotide substitution that resulted in loss of EcoRI restriction site and gain of two additional MspI sites in cox1 and atp1 genes, respectively. There were 28 polymorphic sites among all nucleotide sequences including five reference isolates. Sites with alignment gaps were observed in P4 with one nucleotide deletion in 11 Ethiopian isolates. None of the reference sequence produced frame-shifts, with the exception of the 3-nucleotide deletion in the P4 region by Phytophthora andina, a feature that can be used to distinguish the new Ethiopian isolates from P. andina. While a distinguishing molecular data presented here clearly separated them from P. infestans, 7 % of the isolates that share this feature formed an important component of the late blight pathogen causing disease on Solanum tuberosum in Ethiopia. Thus, these Ethiopian isolates could represent a novel Phytophthora species reported for the first time here.
Asunto(s)
Biodiversidad , ADN Mitocondrial , Filogenia , Phytophthora infestans/clasificación , Phytophthora infestans/genética , Solanum lycopersicum/microbiología , Solanum tuberosum/microbiología , Secuencia de Bases , Etiopía , Haplotipos , Phytophthora infestans/aislamiento & purificación , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Análisis de Secuencia de ADNRESUMEN
The WHO has advocated monitoring adherence to the Food and Agriculture Organization's Code of Conduct to reduce use of highly hazardous pesticides in lower and middle income countries. We re-framed Code articles in terms of farmers' rights and drew on survey data, farmer focus group results, and direct observations of agrochemical stores in Ecuador and Peru to construct indicators reflecting respect for such rights. Use of highly (Ia and Ib) and moderately (II) hazardous pesticides was common. Worse indicators were observed in places with lower education, greater poverty, and more use of indigenous languages. Limited government enforcement capacity, social irresponsibility of the pesticide industry, and lack of farmers' knowledge of the Code were all factors impeding respect for farmers' rights. Addressing the power imbalance among social actors requires informed farmer and farmworker participation in monitoring adherence and active involvement of non-governmental organizations and municipal governments.