Abstract

Vermicompost humic acids (VHA) promote plants’ growth because they have similar effects with auxins. The aim of this research was to evaluate the effect of VHA in some physiological indicators in the micropropagation and acclimatization phase of banana clone Enano Guantanamero. Six concentrations were used (0, 10, 20, 30, 40 and 50 mg L-1) to evaluate in vitro the number of leaves, total chlorophyll content and chlorophyll a-b; also in the acclimatization phase, the plant height, stem diameter and number of leaves at three different times (transplant, 25 days and at the end of this phase-50 days) were determined. Root length and roots dry weight were evaluated at the end of the acclimatization. VHA applied improved total chlorophyll, chlorophyll a-b at concentrations of 20 and 50 mg L-1, but not the number of leaves. In the acclimatization stage, plants height at the end of this period (50 days) were higher with 10 mg L-1 (T1)  VHA, the number of leaves increased at 40 mg L-1 (T4) and the stem diameter was higher at both concentrations. In the evaluation of roots length, there were no significant differences, but the number of leaves was higher at 10 and 40 mg L-1 (T1 and T4) and it decreased at 50 mg L-1 (T5); roots dry weight increased at 40 mg L-1 (T4).  VHA promoted chlorophyll content under in vitro conditions, it reduced the period of acclimatization of banana clone Enano Guantanamero, led to a better growth of plants, and it saved time and resources.

Key words: Acclimatization, humic acid, in vitro crop, Musa sp. 

Abbreviation

DRIFT, Diffuse reflectance Fourier-transformed infrared; HS, humic substances; MS, Murashige and Skoog; UV- VIS, ultraviolet-visible spectroscopy; VHA,  vermicompost humic acids.