Selection of Manihot genotypes tolerant to salinity during initial establishment

Abstract

Salinity is a major environmental constraint for crop productivity in arid and semi-arid regions of the world. Wild species of the genus Manihot are used by ranchers in the Northeastern Semi-Arid as fodder for the herd of small ruminants, due to their rusticity and tolerance to climatic conditions in that region. The evaluation of tolerance during the germination stage of a plant allows a good forecast of its response to salinity. Thus, the objective was to evaluate the germination and initial growth of seedlings of different accessions of wild species of the genus Manihot under salinity conditions. An experiment was carried out in a completely randomized design in a 6 x 3 factorial scheme (accesses x electrical conductivity), with three replications of 10 seeds. The germination and initial growth of six accessions from the Collection of Wild Species of the Genus Manihot of Embrapa Semi-arid were evaluated in a substrate moistened with NaCl solutions in electrical conductivities 0, 4, 8 dS.m^-1. The increase in electrical conductivity inhibited seed germination, with the exception of BGMS38, which showed normal seedlings above 60% at up to 8 dS.m^-1. Gradual increase in the electrical conductivity of the substrate inhibits germination process and initial seedling development.