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ABSTRACT The objective of this article was to estimate the genetic variability and selection gain in the characters related with fruits in assai palms, 68 progenies collected in populations from Afuá city and planted in Amapá state were evaluated. The experiment was conducted in random blocks with two replications and four useful plants per plot. The following characters were evaluated: fruit longitudinal diameter (DLF), the fruit greatest transversal diameter (DTMA), the smallest fruit diameter (DTME); mass from one hundred fruits (P100) and, in bunches: total fruit mass (PTC). There are differences between progenies, denoting the possibility of selection gains. In general, the inheritabilities were medium or high for the characters, but always lower for PTC. The coefficient CVg/CVe was favorable in DTMA and DTME and unfavorable to PTC; the correlations between characters were positive and significant, the selection gain was 16.65% for PTC and from -1.29% to -7.60% in the other characters; the selected progenies were able to associate the desired values in the evaluated characters. The obtained conclusions were that there is high environmental contribution in the phenotypic manifestation of the progenies once the fruit metric dimensions had lower environmental effects and higher genetic effect; there is possibility of genetic gains which are important to breeding programs of this species using the characters simultaneously, although the values had been low, mainly due to the positive correlation presence, where there is preference for reduced fruit size with productivity increase.

This study analyzes the structure and floristic composition of the regeneration of native forest species under black-wattle plantation, established 16 years ago in a riparian area, and it verifies the possibility of the black-wattle be considered an invasive species of this environment. The tree stratum (circumference at breast height (CBH) ≥15 cm) was evaluated in 12 plots of 100 m2, established in four blocks. The natural regeneration stratum (0.3 m height to Casearia sylvestris, Myrsine lorentziana and Zanthoxylum petiolare presented the larger importance value in the tree stratum and Faramea marginata, Myrsine lorentziana and Myrcia glabra the biggest density in the natural regeneration stratum. The ecological characteristics of the species found in several height strata indicated that the forest succession process is in evolution. The black-wattle did not regenerate in this area and the planted trees of this species are in the senescence phase. Only 100 tree/ha of black-wattle were found, which represents 4.5% of the original population. Thus, black-wattle is not an invasive species for this environment.

This study analyzes the structure and floristic composition of the regeneration of native forest species under black-wattle plantation, established 16 years ago in a riparian area, and it verifies the possibility of the black-wattle be considered an invasive species of this environment. The tree stratum (circumference at breast height (CBH) ≥15 cm) was evaluated in 12 plots of 100 m², established in four blocks. The natural regeneration stratum (0.3 m height to