RESUMO
La papa (Solanum tuberosum) Diacol Capiro es uno de los cultivares con mayor producción y consumo interno en Colombia, siendo los departamentos de Cundinamarca y Boyacá, los principales productores. Este cultivo, se ve afectado por un complejo de virus, que disminuye la calidad de los tubérculos y los rendimientos. En este trabajo, se evaluó la prevalencia de los virus de ARN: PLRV, PVY, PVX, PVS, PVV, PYVV, PMTV y PVB, en brotes de tubérculos-semilla certificados, provenientes de la sabana Cundiboyacense, mediante RT-qPCR. Los resultados revelan la ocurrencia de siete de los ochos virus en las muestras, con niveles de infección de 100 % (PVS, PVX y PYVV), 75 % (PLRV), 50 % (PVY), 37,5 % (PMTV) y 12,5 % (PVB). Adicionalmente, con el fin de obtener información de los genomas de los virus detectados, se utilizó secuenciación de alto rendimiento (HTS), de una muestra compuesta (bulk) de brotes, siendo posible obtener el genoma completo del PLRV y el genoma parcial del PVY. Los análisis filogenéticos realizados con dichas secuencias ubicaron a los virus PLRV y PVY en clados, conformados por aislamientos colombianos, con niveles de identidad superiores al 97 %. Estos hallazgos evidencian la necesidad de fortalecer los programas de certificación de tubérculos-semilla de papa en el país, mediante la utilización de pruebas moleculares de detección viral.
Diacol-Capiro is one of the most important potato (Solanum tuberosum) cultivars in Colombia with most production concentrated in the provinces of Cundinamarca and Boyacá. Unfortunately, this crop is seriously affected by several viruses that compromise the quality of tubers and yields. In this work, it was evaluated the prevalence of the RNA viruses: PLRV, PVY, PVX, PVS, PVV, PYVV, PMTV, and PVB in certified tuber-seed sprouts produced in the highlands of Cundinamarca and Boyacá by RT-qPCR. Results revealed a prevalence of 100 % for PVS, PVX, and PYVV; 75 % for PLRV, 50 % for PVY, 37.5 % for PMTV, and 12.5 % for PVB. Additionally, high-throughput sequencing from a sprout´s bulk sample was used to gather genomic information of infecting viruses, which resulted in a partial PVY sequence, and a complete PLRV genome. Phylogenetic analysis revealed that both assemblies cluster within clades comprising other Colombian isolates with more than 97 % nucleotide sequence identity. These findings highlight the need to update potato seed-tuber certification programs in Colombia with the implementation of more sensitive molecular tests.
RESUMO
Potato farmers in India and other developing countries lack timely availability of healthy and good quality potato seed tubers. This is mainly due to conventional seed multiplication techniques which, has suffered inherently from low multiplication rates. The soil medium is generally used for seed tuber production. In order to overcome bottlenecks, a study was conducted to evaluate mini-tuber production potential for selected baskets of potato varieties in different soil-less solid media types compared with soil as a control. Soil-less media technique would also assist in planning for economical and rapid seed multiplication program, along with pathogen-free seed tubers, which will increase production of good quality reliable seed material in the country. This will finally ensure increased productivity of potato crop. With these objectives, an experiment was conducted during the years, 2015–2016 and 2016–2017. Three different soil-less solid propagation media (kalpeat plus, soilrite mix and soilrite mix TC) were tested against control (soil:sand 3:1); for five different varieties (1001, 1002, 1003, 1004 and 1005). Plantlets grown on soilrite mix performed better with higher mini-tuber yield of 548.58 gm/ container (1/2 m²), while for other propagation media, 283.39 gm/container (1/2 m²), 96.08 gm/container (1/2 m²), and 52.61 gm/container (1/2 m²) respectively, were observed for kalpeat plus, soilrite mix TC and control (soil:sand 3:1). Among the varieties tested, viz., 1005 and 1004 produced maximum mini-tubers, between 9 tubers/plant and 5 tubers/plant respectively. Soilrite mix increased the number and size of mini-tubers. Thus, this study concluded that soil-less solid media induced seed potato multiplication is better than traditional soil-based techniques