Presencia de diferentes virus del pimiento ( Capsicum annuum L.) en especies de malezas asociadas al cultivo

Abstract

In a two growth-cycle survey, 30 annual and 13 perennial weed species were determined in different sweet pepper ( Capsicum annuum L.) growing areas of the Limari and Elqui valleys of Coquimbo Region of Chile (29\ub0 to 30\ub0 S lat). The samples were randomly taken in and outside tomato fields, with and without crops present, in winter and spring. A total of 676 weed plants were collected, with a total of 379 samples being analyzed. DAS-ELISA was used to test the presence of Cucumber mosaic virus (CMV), Tomato spotted wilt virus (TSWV), Alfalfa mosaic virus (AMV), Potato virus Y (PVY) and Impatients necrotic spot virus (INSV). A 17% (64) of all collected samples were positive to at least one virus, of which 7.4% (28) came from symptomatic weeds and 9.4% (36) were from symptomless hosts. Jimsonweed (Datura spp.) was positive to CMV and PVY; apple-of-Peru ( Nicandra physalodes ) to AMV, CMV and PVY; black nightshade ( Solanum nigrum ) to CMV and PVY; sowthistle (Sonchus spp.) to AMV and TSWV; small-flower galinsoga ( Galinsoga parviflora ) to AMV, CMV, TSWV and INSV; common lambsquarters (Chenopodium spp.) to AMV, CMV, TSWV, PVY and INSV, among the principle species. Using a relative potential infection index (IPIR), weeds having highest values were small-flower galinsoga (74.7), apple-of-Peru (11.2), black nightshade (6.3) and lambsquarters (6.0). Species such as sowthistle, jimsonweed, bristly mallow ( Modiola caroliniana ), chickweed ( Stellaria media ) and pigweed (Amaranthus spp.) had indexes lower than 1.0. Small-flower galinsoga and apple-of-Peru had more than one virus, and these multiple virus infections were prevalent over single infections. It is imperative to control host weeds within cultivated areas and surroundings to reduce the incidence and dispersal of the viruses in sweet pepper plants.En prospecciones de malezas realizadas durante dos temporadas agr\uedcolas, 30 especies anuales y 13 perennes fueron determinadas en cultivos de pimientos ( Capsicum annuum L.) de los Valles de Elqui y Limar\ued, Regi\uf3n de Coquimbo (29\ub0 a 30\ub0 lat. Sur). Los muestreos fueron aleatorios dentro y fuera de los potreros, con y sin cultivo presente, en invierno y primavera. Se recolectaron 676 plantas de malezas, analiz\ue1ndose un total de 379 muestras. Utilizando la prueba DAS-ELISA se determin\uf3 Virus del mosaico del pepino (CMV), Virus del bronceado del tomate (TSWV), Virus del mosaico de la alfalfa (AMV), Virus Y de la papa (PVY) y Virus INSV (Impatients necrotic spot virus). Un 17% (64) de las muestras fueron positivas al menos a un virus, de las cuales 7,4% (28) provinieron de plantas con s\uedntomas y 9,4% (36) fueron hospederos asintom\ue1ticos. Chamico (Datura spp.) hosped\uf3 a CMV y PVY; nicandra (Nicandra physalodes) a AMV, CMV y PVY; tomatillo ( Solanum nigrum ) a CMV y PVY; \uf1ilhue (Sonchus spp.) a AMV y TSWV; pacoyuyo ( Galinsoga parviflora ) a AMV, CMV, TSWV y INSV; quing\ufcilla (Chenopodium spp.) a AMV, CMV, TSWV, PVY e INSV, entre las principales. Usando un \uedndice potencial de infecci\uf3n relativa (IPIR), los mayores valores se obtuvieron con pacoyuyo (74,7), nicandra (11,2), tomatillo (6,3) y quing\ufcilla (6,0). Especies como \uf1ilhue, chamico, pila-pila ( Modiola caroliniana ), quilloi-quilloi ( Stellaria media ) y bledo (Amaranthus spp.), tuvieron \uedndices inferiores a 1,0. Nicandra y pacoyuyo portaron m\ue1s de un virus y estas infecciones m\ufaltiples prevalecieron sobre las simples. Controlar malezas portadoras tanto dentro como en las inmediaciones de los potreros, resulta imperioso para poder minimizar la incidencia y dispersi\uf3n de las enfermedades virales en pimientos