SEED COAT AND MICROPHYLE-HILIUM PERMEABILITY IN WILD AND CULTIVATED BEAN SEEDS

Abstract

The objective of this research was to determine the role of different structures on the surface of common bean (Phaseolus vulgaris L.) seed in the water uptake process. Seeds of seven wild and five cultivated genotypes were given the following treatments: intact seed, scarified seed, seed with the microphyle-hilium sealed and open seed. Wild genotypes and hard shell cultivars, showed a low water uptake rate when exposed to water for several hours. In all genotypes, seed scarification accelerated water intake to a similar level that the one exhibited by open seeds. The seed coat and the microphyle and hilium showed a differential participation in the water uptake process among the different genotypes. Cultivars Bayo Baranda and Pinto Villa showed a water uptake kinetics similar to the one exhibited by wild genotypes under microphyle-hilium sealed treatment; those .genotypes, in addition to the hard shell, displayed an important participation of the microphyle-hilium in the water uptake process.