Viability of seeds of two varieties of Coffea arabica L. using different pretreatments in the tetrazolium test

Abstract

This research attempted to determine the efficacy of the tetrazolium test in the evaluation of the seed viability of two varieties of Coffea arabica L. (‘Castillo’ and ‘Cenicafé’). The fruits were obtained from crops located in the municipalities of Salazar de las Palmas and Arboledas (Norte de Santander - Colombia). The test was carried out with embryos manually extracted from the seeds using tweezers. Three pretreatments were established: distilled water, sodium hypochlorite (2.5 %), sucrose (10 %), and a control (no pretreatment). Embryos were placed in a cysteine solution (0.5 %) to prevent oxidation, then immersed in tetrazolium solutions with concentrations of 0.035 %, 0.075 %, and 0.1 % for a period of 6, 9, and 12 hours in darkness. The results of the viability test were validated with seed germination, using the wet paper towel method in darkness. The best viability percentages were found with the application of sodium hypochlorite (NaClO 2.5 %), with a high correlation with the germination percentage. The use of pretreatments improved the efficiency of the viability test and allowed the use of low concentrations of the reagent (0.035 %), giving the farmer a quick and less expensive alternative to determine germination capacity.