Regeneração e conservação in situ de recursos genéticos de butiá (Butia odorata, Arecaceae)

Abstract

Butia odorata is a palm tree from the Arecaceae family, which is part of the identity and culture of southern Brazil. With the significant decrease of areas where there were jelly palm groves and the difficulty related to the regeneration of this species, it is in threat of extinction. The conservation of these remaining areas can be considered the key element for the recovery and maintenance of the still existing palm groves. This work had the general objective of contributing to the advancement of knowledge related to the regeneration and in situ conservation of B. odorata genetic resources. The specific objectives were to evaluate a production of fruits and seeds; to evaluate the B. odorata seed bank in the soil in conservation area of palm groves in the Pampa Biome; monitoring regeneration of palm grove under different livestock management practices. The study was developed in a well conserved in situ palm grove, at Tapes (RS State, Brazil). In March 2017, total bunch weight, number of fruits per bunch, fruit color, fruit format, weight of 50 fruits, weight of 50 fruit pulp, weight of 50 endocarps, number of seeds per fruit, height and diameter of the fruits were evaluated. The endocarps in soil were collected in samples from different areas of the palm grove considering presence and absence of cattle. The regeneration of palm grove was monitored under different grazing management practices: extensive cattle grazing, intermittent grazing and exclusion of cattle. In the autumn of 2017, the number of new palms, stature of these plants when presented pinned leaves and height of the herbaceous vegetation were evaluated in six plots of 400m2. The fruit traits variability was evidenced. The total weight of bunches varied from 1.85kg to 13.51kg. Most of the endocarps found in the soil samples were damaged or with unviable seeds. The plot with grazing exclusion had a higher number of juvenile palms, but these were already present there when the area was excluded. In the intermittent grazing management plot, which is the exclusion of grazing in the coldest months of the year in which the germination of the jelly palm seeds usually occurs, a higher number of small young palms was observed, showing a significant palm grove regeneration. The results indicate that the process of palm grove regeneration is occurring and its success depends on the type of management adopted.