Desifestação e influência do substrato na germinação in vitro de Mimosa ophthalmocentra Mart. Ex. Benth.

Abstract

Mimosa ophthalmocentra Mart. ex Benth is a common plant in the Caatinga, often found in many environments, yet little studied. The presence of microorganisms are important factors that can reduce the effect of in vitro germinating seeds and disinfestation protocols are designed to provide aseptically plant quality and increased production chain, therefore, in vitro propagation from seed presented as an alternative for supply of healthy plants free of pathogens. Given the need for more detailed studies on the germination is that this research aims to evaluate the potential of M. ophthalmocentra ex BenthMart seed germination, to determine the best substrate quality for germination and seedling development, and to identify the action of the best disinfest agent and his exposure time. The experiment was conducted at Tissue Culture Laboratory of Plant UFCG. The seeds came from plants located in “Lago da Cruz” site in the municipality of Sumé, semiarid region of Paraíba, which were separated and selected. five disinfestation treatments were inoculated: seeds directly in the middle, without treatment for disinfestation (T1), immersion in 70% alcohol for 10 minutes, associated with immersion in NaOCl in of 2.0% and 1.5% for 10 and 30 minutes respectively (T2 and T3); 99.3% alcohol for 20 minutes, associated with the immersion in NaOCl at concentrations of 1.0% and 0.5% for 20 and 40 minutes (T4 and T5). The seeds were then subject to emerges later and seeded into glass pots and Petri dishes containing agar-water and paper-type substrates Germitest respectively. All disinfection processes, and lopping inoculation was performed in a laminar flow hood with all the autoclaved materials with appropriate aseptic precautions. The design was completely randomized, with four replicates per treatment, each repetition being composed of 10 sampling units (seeds) in a factorial 5x2 (disinfest agent x substrates). The results showed that the water-agar was the best substrate applied as it reached the best percentage of germination, first count and germination speed, and the best disinfestation was T2. Thus, immersion for 10 minutes in 70% ethanol and 10 minutes in sodium hypochlorite at 2.0% did not affect the germination of seed disinfection providing the best when they were used in a water-agar substrate.