Physcomitrium acutifolium broth. (Funariaceae): proposição de um novo modelo experimental para estudos de entre os musgos em condições de laboratório

Abstract

Plants are organisms known for their importance as models of biological studies. The use of these organisms in vitro culture is an important tool, both in applied studies and in other commercial applications. In this line, one group that have stood out are the bryophytes. Bryophytes lato sensu are the most successful evolutionary group among plants, along with Angiosperms, in number of species, geographical distribution on all continents and habitat diversity. Also, more particularly, the Bryophyta stricto sensu group, popularly known as mosses, has as its dominant phase haploid, gametophytic stage, and transient to diploid phase, sporophytic and reproductive stage. Over the years, the usefulness of mosses has become increasingly known and studied. Among the characteristics that clearly demonstrate the ecological importance of their study it can be pointed out that, because they do not have cuticle or epidermis, and have simple gametophytic structures, this provides a greater absorption and retention of nutrients, as well as pollutants, metals and other substances present in the atmosphere and make them excellent models for in vitro experimentation between plants. The present study refers to the evaluation of several aspects that contribute to the improvement and optimization of in vitro growth of Physcomitrium acutifolium moss in order to transform it into a new experimental model among moss species. First tests on 3 culture media commonly used for plant cultivation (KNOP + ME, MS and BCD), where 3 plant gametophytes were placed in each glass and 4 replicates were made so that the analysis could be done. which would have better growth in measure and weight. Subsequently tests were performed with 5 different phytoregulators: indole-3-acetic acid (AIA), 2-aminoisobutyric acid (AIB), kinetin (KIN), 6- benzylaminopurine (BAP) and abscisic acid (ABA) in 3 doses + control. 6 plant gametophytes in each glass in replicates of 4. Gametophytes were measured and weighed and after that possible polymorphisms in the plant genome were analyzed using ISSRs primers. It was concluded that the best medium to be used for measurement and weight, respectively, would be MS and KNOP + ME. It was observed that none of the treatments with phytoregulators resulted in statistically significant difference regarding the measurement and weight, being necessary more tests in number of doses and different conditions. Already in the analysis of polymorphisms through a copheenetic dissimilarity relationship based in phenogram and in binary matrix to asses table the absence and presence of amplifications by the markers ISSRs, showed that the phytoregulators, could cause polymorphisms in the genome of Physcomitrium acutifolium in different doses, being the most present IBA in 0, 5 µM and 1.0 µM BAP, respectively