Ecophysiological aspects of production of Melanoxylon brauna Schott. seedlings

Abstract

The species Melanoxylon brauna Schott. is classified as vulnerable to extinction due to its high level of logging and lack of replanting. Numerous problems are attributed to this species, such as obtaining and viability of seeds, as it is attractive to predators; production of seedlings on a commercial scale in nurseries, due to the substrate used in their propagation, fertilization and excess water, which leads to death. The objective of this work is to analyze the survival and quality of M. brauna seedlings when produced in different soil/substrate compositions, aiming to define the optimal soil/substrate relationship for large-scale seedling production. The soil close to the mother tree (T3) was the one that showed the greatest growth of seedlings after 150 days of setting up the experiment. The orthogonal contrast shows that the underground land (T2) is different for treatments 4; 5; 6 and 7, which have soil close to the matrix in the substrate mixture, which is associated with the activity of the enzymes APX, CAT, POD and SOD. The soil enzymes β-glucosidase and arylsulfatase showed high activity in the organic substrate (T1), followed by the soil close to the parent tree (T3), suggesting that these enzymes are important biochemical markers for evaluating soil quality, however, it is not sufficient to maintaining the survival of seedlings in the organic substrate. For the production of M. brauna seedlings, it is recommended to use 100% soil close to the braúna parent tree. Therefore, it is necessary to elucidate whether the interaction with specific microorganisms, or some metabolite produced by them, by the plant and/or this interaction, are responsible for this survival of M. brauna seedlings