Resistencia genética a Sporisorium reilianum f. sp. zeae en líneas seleccionadas de maíz (Zea mays L.) con endospermo blanco y amarillo

Head smut ( Sporisorium reilianum f. sp. zeae ) of maize ( Zea mays L.) is an important disease present in Mexico, including the Mezquital and Toluca Valleys. The objective of this research was to identify C 2 -S 1 and C 2 -S 2 maize lines adapted to Mexican highlands to be used in a breeding program for disease resistance and good agronomic characters. Seed of lines were inoculated with a suspension of .7x10 7 teliospores mL -1   of S. reilianum f. sp. zeae with 1% sodium carboximethyl cellulose and planted in a greenhouse. Plants were monitored until tassel stage, when incidence of the disease was recorded. In 258 C 2 -S 1 lines with white endosperm showed an incidence of 92.3% and 41.7% in 71 lines with yellow endosperm. Based on incidence and agronomic characters, 38 and 24 C 2 -S 1 lines with white and yellow endosperm, respectively, were selected and self-pollinated in the field. A total of 123 and 114 C 2 -S 2 lines with white and yellow ensoperm, respectively, inoculated with teliospores of the pathogen showed incidence of the disease up to 42.8% and 28.5%, respectively. Inoculation with teliospores and planting in te greenhouse resulted in the identification of maize lines with different percentages of infection allowing the selection of resistant lines, proving the efficiency of the technique.