Use of Temporal Immersion Systems for the multiplication of nodal segments of Dioscorea alata L. in the ‘Pacala Duclos’ clone

Abstract

In order to develop efficient propagation protocols, temporary immersion systems composed by two glass flask with 5 000 ml of capacity were used to multiply nodals segments from yam clone ‘‘Pacala Duclos’’. The working objectives for evaluation were: time and frequency of immersion, inoculum density, time and renewal volume of culture medium and multiplication stage length on propagation coefficient of nodal segments. Results permitted to define that using 10 minutes immersion time and immersion frequency each three and six hours, the highest increments in the multiplication coefficients (10.1 and 9.8 respectively, without significant differences between them) were obtained. The most favorable result for the multiplication coefficient (10.8) was obtained when 50 explants per culture flask was inoculated. When the renewal was carried out 24 days after culture with 2 000 ml culture medium, the most advantageous result was shown for the multiplication coefficient, with 14.1. Subcultures were developed 49 days after culture because the highest coefficient multiplication (15.2) was noticed. A higher culture time did not influence in the multiplication coefficient significantly. Key words: culture medium, Dioscorea alata L., inoculum density, multiplication coefficient