REACCI 3N DE CULTIVARES COMERCIALES DE MA\ucdZ ( Zea mays L.) A LA INOCULACI 3N MEC\uc1NICA CON TRES POTYVIRUS

Con la finalidad de evaluar la reacci\uf3n de 21 cultivares comerciales de ma\uedz a la inoculaci\uf3n mec\ue1nica con las razas MDMV-V, MDMV-A, SCMV-MB y JGMV-O se realizaron cuatro ensayos, uno por cada raza viral, utilizando un dise\uf1o completamente aleatorizado con 21 tratamientos (cultivares), cinco r\ue9plicas por tratamiento y cuatro plantas por r\ue9plica, bajo condiciones de invernadero (23-27 \ub0C, 51-78 % HR, 15.000 lux) en Maracay, Aragua, Venezuela. Los cultivares evaluados fueron Danac 344, Danac 255, Danac 374, DK 2045, DK 7088, DK 370, Dow 2382, Dow 2384, Dow 2B710, IN IA SQ-2, Fonaiap 1, Tur\ue9n 2000, P 4063, P 4082, P 30F35, Dorado 5, Se floarca 108, Sefloarca 02, SK 5071, SK 4008 e Himeca 2020. Las plantas fueron inoculadas a los 7 y 14 d\uedas despu\ue9s de la siembra. Para la evaluaci\uf3n se utiliz\uf3 el \uedndice de la enfermedad (IE), el cual se obtuvo media nte la ecuaci\uf3n: IE =3D 4W + 3X + 2Y + Z, que es igual al porcentaje acumulado de plantas enfermas a los 6, 11, 16 y 28 d\uedas despu\ue9s de la primera inoculaci\uf3n, respectivamente. El an\ue1lisis de los resultados se realiz\uf3 mediante la prueba no param\ue9trica de Kruskal-Wallis para comparaciones entre tratamientos. Pocos cultivares resultaron resistentes a las razas MDMV-V y SCMV-MB, que son las m\ue1s severas y agresivas; sin embargo, la mayor\ueda present\uf3 un buen grado de resistencia al MDMV-A y JGMV-O. Los cultivares m\ue1s promisorios ante las cuatro ra zas virales fueron DK 7088, DK 370, Dow 2B710, Danac 344 y Dorado 5. Palabras claves del Autor adicionales: JGMV, MDMV, SCMV, raza viral, resistencia ABSTRACT REACTION OF COMMERCIAL CULTIVARS OF MAIZE ( ZEA MAYS L.) TO MECHANICAL INOCULATION WITH THREE POTYVIRUS In order to evaluate the reaction of 21 maize cultivars to th e mechanical inoculation with the strains MDMV-V, MDMV-A, SCMV-MB, and JGMV-O four tria ls, one for each viral strain, were conducted using a completely randomized design with 21 treatments (cultivars), five replicates per treatment and four plants/replica, under greenhouse conditions (23-27 \ub0C, 51-78 % R H, 15.000 lux) in Maracay, Aragua State, Ve nezuela. The cultivars evaluated were Danac 344, Danac 255, Danac 374, DK 2045, DK 7088, DK 370, Dow 2382, Dow 2384, Dow 2B710, INIA SQ-2, Fona iap 1, Tur\ue9n 2000, P 4063, P 4082, P 30F35, Dorado 5, Sefloarca 108, Sefloarca 02, SK 5071, SK 4008 and Himeca 2020. The plants were inoculated at 7 and 14 days after planting. During the evaluation, the disease index (DI) was determined as follows: DI =3D 4W + 3X + 2Y + Z, where W, X, Y y Z represent the total percentage of plants with sympto ms by 6, 11, 16, and 28 days after the first inoculation, respectively. For the analy sis of the results a Kruskal-Wallis nonparametric test for multiple co mparisons among treatments was a pplied. Few cultivars responded effectively to the strains MDMV-V and SCMV-MB, which are the most severe and aggressive; however, almost all were resistant to MDMV-A and JGMV-O. Cultivars with the best performance to the four vira l strains were DK 7088, DK 370, Dow 2B710, Danac 344 and Dorado 5. Additional key words: JGMV, MDMV, SCMV, resistance, viral strain