Influência de genótipo, agentes gelificantes, precursor (ACC) e inibidores (AVG e STS) do etileno e tipo de vedação na morfogênese in vitro de berinjela (Solanum melongena L.)

• Autor(a) principal: Ribeiro, Ana Paula de Oliveira
• Data de Publicação: 2006
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1292
• topic: Beringela; Propagação in vitro; Banco de germoplasma; Análise mineral; Organogênese; Embriogênese; Eggplant; in vitro propagação; Germoplasma bank; Mineral analysis; Organogenesis; Embryogenesis; CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA VEGETAL

In the present work, studies related to aspects of the morphogenesis and of the behavior in vitro of Solanum melongena they were accomplished. This way, was aimed at to determine the influence of the genotype, of the salt concentration of and of the type of agent gelificante, of inhibitors of the biosynthesis and of the action and the ethylene precursor and of the type of sealing in the morphogenesis in vitro. For such, the genetic variability among 16 accessions of eggplant (Solanum melongena L.) from BGH-UFV was studied, as well as the cultivar Embu, by means of their morphological characterization based on the in vitro response. The utilization of the Tocher method allowed the formation of three groups and six different subgroups distincts. Both the effects of salt concentration of the MS medium and gelling agents in in vitro germination of eggplant seeds and the absorption capacity of the nutrients of these seedlings were evaluated. The influence of physiological conditions of explants obtained from these seedlings upon organogenesis and somatic embryogenesis was also evaluated. During germination, the development of epicotyl and leaves was observed only in the seedlings developed in full strength MS medium. In the medium of embryogenesis induction, it was observed that the number of embryos formed in Agargel (Sigma Chem. Co., USA) was smaller whereas only the characteristics weight and dry matter were significant in the organogenesis induction medium. For the elongation of shoot tips, the best treatment was the medium containing 50% of MS salts. Through the determination of content of the elements in the gelling agents, a great variation in the chemical elements was observed; for the majority of the elements, the concentration was lower in Agar (Merck, Germany) and higher in Phytagel® (Sigma Chem. Co., USA). Concerning purity test, Agar proved to be the most impure, followed by Agargel and finally by Phytagel . The effect of ethylene on the somatic embryogenesis and organogenesis was evaluated. In order to perform such evaluation, the medium was supplemented with inhibitors of biosynthesis [aminoethoxyvinilglycine - AVG (Sigma Chem. Co., USA), and its commercial product Retain® (Valent BioSciences Corporation, Illinois, USA)] and action (silver thiosulphate - STS) and the precursor [1-aminocyclopropane-1- carboxylic acid ACC (Sigma Chem. Co., USA)] of the plant growth regulator. By means of regression equation, it was observed that for the parameter frequency of embryos, with the addition of ACC to the medium, there was an increase until about 20 MM, followed by a reduction, whereas a peak at 3 MM was obtained with the addition of AVG, on the other hand, a reduction was verified in the presence of STS. In the organogenesis inductor medium, with the increase of the concentration of ACC and AVG, a reduction in both the weight of fresh matter and the frequency of shoot buds was observed as well as a reduction of shoots and root primordia; Moreover, there was an increase in the diameter of the explants. The supplementation of STS in the medium led to a increase in the characteristic shoot frequency and a decrease in the other characteristics. By comparing the results obtained with AVG and Retain®, it was observed a decrease in all the characteristics when Retain® was added. In addition, it was evaluated the influence of the type of sealing in the morphological characteristics of eggplant in the induction of somatic embryogenesis, organogenesis as well as the anatomical and morphological characteristics in elongation. In order to evaluate the sealing effect, the petri dishes were sealed with hypoallergenic tape (MicroporeMR 3M, Brazil), Parafilm M (Sigma Chem. Co., USA), and plastic film of Polyvinyl Chloride - PVC (Goodyear®, Brazil). The flasks were sealed with PVC, autoclaved polypropylene closures (TSF) and the same closures containing two filters (TCF) of 10 mm in diameter and of 0.22 m of pore (MilliSeal®, Japan). It was verified that the seedlings kept in the flasks sealed with TCF were more vigorous. The type of sealing influenced all the anatomical characteristics analyzed in which it was observed that a higher amount of gas exchanges is correlated with the degree of tissue differentiation. The number of stomata and epidermis cells were greater in the abaxial face in all the sealing treatments.