Déficit hídrico estimulado por Polietilenoglicol em sementes de feijão-caupi

Abstract

This study investigated the effects of water stress induced by Polyethylene Glycol 6000 (PEG 6000) on the germination of seeds from four genotypes of cowpea (Vigna unguiculata (L.) Walp.), obtained from local communities in the region of Picos-PI, namely: Sempre verde, Canapú, Santo Inácio, and Chumbinho, under controlled laboratory conditions. The following parameters were evaluated: germination percentage (G%), first germination count (FGC%), and germination speed index (GSI) at five osmotic potentials (0.0; –0.2; –0.4; –0.6; and –0.8 MPa). Statistical analysis revealed a significant interaction between genotype and osmotic potential, highlighting the importance of varietal selection for environments with water restriction. All germination parameters significantly decreased with the reduction of osmotic potential, with genotype V4 (Chumbinho) being the most tolerant to the imposed conditions, while V2 (Canapú) showed greater sensitivity. The –0.8 MPa condition inhibited germination in all varieties, and the –0.6 MPa condition allowed low germination rates only in variety 4 (Chumbinho). These findings provide support for the selection of varieties better adapted to the semi-arid region, regarding the evaluated germination traits.