Portal de Periódicos da CAPES

Determination of viral diseases and insect vectors on weeds adjacent to fields of vegetable crops.

2003; Pontifical Catholic University of Chile; Volume: 30; Issue: 3 Linguagem: Inglês

10.7764/rcia.v30i3.1312

0718-3267

Gastón Apablaza, Jaime Apablaza, Paula Reyes, Esteban A. Moya,

Plant and soil sciences

Viral diseases and insect vectors from weeds - growing adjacent to fields of tomato, pepper, melon, watermelon and squash - were determined in the Vth and Metropolitan regions of Chile. Two hundred and eleven weed samples showing virus symptoms were analyzed for virus presence by DAS-ELISA and by mechanical inoculation to indicator plants. The relative importance of weeds, in decreasing order, was: Datura stramonium, Amaranthus spp., Raphanus sativus, Chenopodium album, Galega officinalis, Conium maculatum, Sonchus asper, Malva spp., Urtica urens, Bidens spp., Brassica campestris, Sorghum halepense and Solanum spp.. One to five of the following viruses were found infecting these weeds: alfalfa mosaic virus (AMV), cucumber mosaic virus (CMV), tomato spotted wilt virus (TSWV), potato virus Y (PVY), tomato mosaic tobamovirus (ToMV) and watermelon mosaic virus - 2 (WMV 2). Syndromes of some of the viruses on weeds and on pepper plants are described. Aphids, thrips and some Lepidoptera species were also collected from the weeds under study and identified. Myzus persicae, a vector of CMV, WMV2, AMV, and PVY; and Thrips tabaci, a vector of TSWV, were commonly found. This information indicates that weeds growing, next to fields of crops, are inoculum sources of the viruses and hosts of their vectors. Se determinaron las enfermedades virosas e insectos vectores presentes en malezas adyacentes a cultivos de tomate, pimiento, melon, sandia y zapallo, en las Regiones V y Metropolitana de Chile. Se analizaron 211 muestras de malezas que presentaban sintomas visibles de virosis, provenientes de 50 potreros, para determinar la presencia de virus utilizando la prueba serologica DAS-ELISA y transmision mecanica a plantas indicadoras asi como tambien a pimiento. Se determino el indice de importancia relativa de las 13 especies de malezas que presentaron infeccion viral. De mayor a menor importancia fueron: Datura stramonium, Amaranthus spp., Raphanus sativus, Chenopodium album, Galega officinalis, Conium maculatum, Sonchus asper, Malva spp., Urtica urens, Bidens spp., Brassica campestris, Sorghum halepense y Solanum spp.. En estas malezas se encontraron uno a cinco virus, siendo los principales: el virus del mosaico de la alfalfa (AMV), el virus del mosaico del pepino (CMV), el virus del marchitamiento manchado del tomate (TSWV), virus Y de la papa (PVY), virus del mosaico del tomate (ToMV) y el virus del mosaico de la sandia (WMV-2). Se describe su sintomatologia preidentificatoria que producen en malezas, plantas indicadoras y plantas de pimiento (Capsicum annum var. grossum). Se colectaron e identificaron afidos, trips y algunos lepidopteros en las mismas especies de malezas en estudio. Myzus persicae es vector de CMV, WMV-2, AMV y PVY; y Thrips tabaci es vector de TSWV, ambos insectos frecuentemente encontrados. Esta informacion permite afirmar que las malezas adyacentes a estos cultivos horticolas son fuentes de inoculo de estos virus y de sus vectores.