Susceptibilidad y mecanismos de adaptacion de genotipos de frijol a la clorosis ferrica.

English. Two experiments were carried out under greenhouse conditions. In the first one the susceptibility to iron chlorosis was evaluated in 23 cultivars of dry beans (Phaseolus vulgaris L.) using the Hoagland's nutrient solution at 0.1 ppm level of Fe-EDTA. It was found out that Bayo Zacatecas was the most tolerant genotype (Fe-efficient), while Garbancillo Supremo was the most susceptible (Fe-inefficient). In the second experiment, both Bayo Zacatecas and Garbancillo Supremo genotypes were grown with 0 and 2 ppm levels of Fe-EDTA in a Steinberg's nutrient solution. Bayo Zacatecas showed higher and sooner acidification response; such response can be related with its Fe-efficiency. Likewise, Bayo Zacatecas showed the highest values of chlorophyll concentration and nitrate reductase activity in comparison with Garbancillo Supremo. Both chlorophyll concentration and nitrate reductase activity were related with the genotypes Fe-efficiency. About the mineral concentration, the highest values were found in the Fe-inefficient genotype without Fe-EDTA addition.

Spanish; Castilian. Se realizaron dos experimentos en condiciones de invernadero. En el primero se evaluo la susceptibilidad a la clorosis ferrica de 21 variedades y dos lineas de frijol (Phaseolus vulgaris L.), usando 0.1 ppm de Fe-EDTA en la solucion nutritiva de Hoagland. Se encontro que Bayo Zacatecas fue la variedad mas tolerante (Fe-eficiente) y Garbancillo Supremo la mas susceptible (Fe-ineficiente). En el segundo experimento, ambas variedades fueron sometidas a 0 y 2 ppm de Fe-EDTA en la solucion nutritiva de Steinberg; se observo una mayor y mas rapida acidificacion de la solucion nutritiva con Bayo Zacatecas, lo que posiblemente le confiere en parte su Fe-eficiencia. Asimismo, esta variedad presento la mayor concentracion de clorofila y la mayor actividad nitrato reductasa, en comparacion con Garbancillo Supremo; ambas variables estuvieron relacionadas con la Fe-eficiencia de las variedades. La mayor concentracion mineral se observo en Garbancillo Supremo sin adicion de Fe-EDTA.