Comportamento de três cultivares de gergelim [Sesamum indicum L.] em condições salinas

Abstract

This study was developed at the Seed Analysis Laboratory of the Plant Science Departament of the Federal University of Ceará, Brazil during the Agricultural years of 1995 and 1996. The research dealt with the germinative behavior of three sesame cultivars, v. g. , CNPAG 2, CNPAG 3 and "Seridó-1" under saline (NaCl) solution concentrations. The seeds were sowed, under laboratory conditions, at 0, 25, 50, 75, 100, 150, 200, 250 and 300 mM of NaCl concentrations in sheets of "Geimitest" paper which had previously been sterilized in autoclave. They were then transferred to a germination chamber at 30±1°C and kept for seven days. The experimental unit was made up of fifty seeds replicated four times. Evaluations comprised assessment of healthy seedlings, seedlings growth, rootlet lengths, fresh and dried matter weigths. Salt solution concentrations have hadan inversely proportional effect over the studied variables for all three sesame cultivars. The adverse effects were more intemsely observed from 75 mM and above to the CNPAG 2 cultivar and 50 mM to CNPAG 3 and "Seridó-1" cultivars. Seed germination was substantially reduced as salt solution concentration increased. The highest tolerance level for CNPAG2 cultivar took place between 250 and 300 mM of NaCl. In relation to CNPAG3 and "Seridó-1" cultivars these limits standed between 200 and 250mM. It was observed that the dried matter weight has interfered in a high depth data interpretation. This is specially noticed when seedling growths were negatively influenced by the saline conditions. This is an inductive reasoning to their evaluations through methods which could allow the absorbed salts removal.