Germinação assimbiótica e desenvolvimento de Dendrobium nobile Lindl. sob efeito de reguladores hormonais e água de coco

Abstract

Orchidaceae differs of most botanical families by its seeds did not have enough reservations for germination. The present work aimed: 1. to study the influence of plant growth regulators BAP (6-benzylaminopurine) e GA3 (gibberellic acid), at concentrations of 0.0; 2.0 and 5.0 mg L-1, as pre-germinative treatment in the process of initial development of Dendrobium nobile Lindl seedlings; 2. to determine the volume of coconut water (0; 50; 100; 150 and 200 mL L-1), that, added to culture media, promoted better germination and in vitro cultivation of D. nobile. Seeds of D. nobile that were produced by manual self-pollinating were used as material of study. After six months of sowing and keeping in germination and growth chamber with controlled temperature and photoperiod (12 hours and 23 ºC ±), seedlings were removed from pots and evaluated about number, percentage of germination, fresh mass, height, diameter and number of psedobulbs, number of leaves, number of roots and length of the greatest root. Completely randomized experimental design was used. Every variables and vegetal attributes were submitted to variance analysis and when they were significative, to regression analysis. D. nobile seeds germinated more in the absence of plant growth regulators and treatments with BAP or GA3 for imbibitions of seeds influenced statistically in vitro development of D. nobile. The addition of 200 mL L-1 of coconut water to culture media promoted the best results for plant heights, number or roots, number of pseudobulbs and fresh mass of D. nobile.