Xbutyagrus nabonnandii (Prosch.) Vorste, (Arecaceae): palmeira rara, estéril e de morfologia variável?

Abstract

xButyagrus nabonnandii (Prosch.) Vorste, Butiaodorata (Barb.Rodr.) Noblick and Syagrus romanzoffiana (Cham.) Glassm, belong to Arecaceae and are native to Rio Grande do Sul (RS), Brazil. These palm trees have economic, cultural, landscape and environmental importance in the regions of occurrence. Due to anthropogenic actions, there is a reduction in natural areas and, consequently, a reduction in their natural populations. In this sense, it becomes important to know the morphological and reproductive characteristics of the specimens, especially the hybrid produced from the natural crossing between B. odorata and S. romanzoffiana, in order to promote knowledge that results in actions that result in germination, propagation and preservation of xB. nabonnandii. Our results demonstrated that the hybrid is fertile and not rare, since its seeds germinated, unlike those described in the literature that consider it as a palmmule, as it is infertile. As for its rarity, also described in the literature, it was refuted by the data collected in our work, since individuals were identified in different municipalities of RS. The fruits of these palm trees are much appreciated by the fauna and, specifically, the Butia juice, which is widely used in regional gastronomy, as well as the leaves serve as raw material for various handicraft products. The general objective of this work was to determine the comparative vegetative and reproductive morphometry between hybrids and their naturally occurring parents located in four municipalities, (RS), Cachoeira do Sul, Porto Alegre, Manoel Viana and Venâncio Aires.The results are presented in three chapters: In Chapter I, a bibliographic review of the Arecaceae was carried out, their attributes, distribution, importance and state of conservation, emphasizing the specimens mentioned above. In chapter II, analyzes of correlations between morphological and reproductive characteristics of four populations of xB. nabonnandii were carried out, approaching the morphological diversity existing between populations and the processes of production and seed germination. In chapter III, a comparative qualitative and quantitative morphometry study was carried out between the hybrid and the parents, in order to establish the similarities between the three specimens, as well as to identify the characteristics of the hybrid, in order to identify it in field activities. Among the variables analyzed, those that most contributed to separating the hybrid from the parents were the variables stem texture with bases of the remaining sheaths spaced incrusted along the stem, slightly mucilaginous mesocarp, presence of a seed in the endocarp, followed by the analysis of the symmetrical position the asymmetry of pores in pyrene. In chapter IV, artificial hybridization was performed between pollen grains of S. romanzoffiana and ovules of B. odorata with the aim of artificially producing new individuals of x B. nabonnandii.