Indução à embriogênese somática e identificação de marcadores ISSR em antúrio

Abstract

Anthurium is an important ornamental species for floriculture's agribusiness. Thus, it is very important to ensure the success of its cultivation. The use of biotechnology allows the development of effective techniques for in vitro propagation. One of these techniques is the somatic embryogenesis. However, beyond these efforts, another technique that can effectively contribute to the success of Anthurium cultivation, is the characterization of anthurium's cultivars, by means of molecular markers. Therefore, the study was divided into two experiments. Experiment 1: The objective was to establish an induction protocol for somatic embryogenesis for the anthurium's cultivars Jureia and Luau, using nodal segments as explants. It was studied the effect of the interaction among the factors cultivar, growth regulator type and concentration on oxidation (%) and formation of embryogenic calli (%). The scanning electron microscopy (SEM) was used to identify whether the structures formed from the explants showed embryogenic characteristics. The evaluations about oxidation showed that Jureia is the most sensitive cultivar, and that the medium added with NAA is more prone to oxidation. As for the formation of embryogenic calli, it was found that Luau has more embryogenic potential and it was established the following protocol for induction of somatic embryogenesis for the two studied cultivars: nodal segments must be maintained for 75 days, in the dark, in the medium ESA (Pierik 1976 modified) supplemented with 7.5 mM of NAA. Experiment 2: The objective was the selection of ISSR markers for molecular characterization of anthurium's cultivars Sublime, Luau, Jureia and Maré, using leaf samples of in vitro established plants, from indirect organogenesis, and samples of embryogenic calli. The DNA extraction was made, showing a genetic material of good quality. The PCR of the 18 ISSR markers was made and the reaction products were visualized by electrophoresis. The revealed fragments in the agarose gel were transformed into binary data [1- presence of band; 0 - absence of band], allowing the classification of the samples in terms of genetic distance in a dendrogram. It was found that all the ISSR used showed polymorphism, being effective to characterization of the anthurium's samples studied. Cultivar-specific markers were identified. It was found that Sublime is the cultivar genetically most stable and Maré the most unstable. These results provide new perspectives for the in vitro propagation, and are useful for breeding and protection of the studied anthurium's cultivars.