Conduziu-se este trabalho, com os objetivos de estudar as características biométricas e físicas dos frutos e sementes de Melanoxylon brauna e estabelecer estimativas de correlação entre as variáveis. Os frutos maduros de Melanoxylon brauna foram coletados em cinco árvores, no município de Leopoldina (MG). Mediu-se o comprimento (CF), a largura (LF) e a espessura (EF) dos frutos nas duas extremidades e uma na parte mediana. Quantificaram-se as massas de matéria fresca (MMF), o número de estruturas membranosas (EM/F) e de estruturas membranosas vazias por fruto (EMV/F). As sementes foram classificadas como normais (SN), danificadas por insetos (SDI) e malformadas (SMF). Os dados foram analisados por meio de estatística descritiva, de ajuste de distribuições estatísticas, de análise de correlação e de análise de regressão. A função-densidade de probabilidade Weibull foi ajustada para as características dos frutos e das sementes. As características biométricas das sementes variam menos do que a dos frutos. Houve correlações positivas significativas do comprimento do fruto com as estruturas membranosas por fruto, da massa da matéria fresca do fruto com estruturas membranosas por fruto e da massa da matéria fresca com o número de sementes normais. Além do comprimento do fruto com o número de sementes normais por fruto. A largura do fruto com as estruturas membranosas por fruto e, com sementes malformadas por fruto, apresentaram correlações negativas e significativas.

Geonoma schottiana is an underbrush palm which is found in high densities in tropical forests. This species is known for having an asynchronous fruit producing pattern, over all seasons of the year, thus being an important food source for frugivores. This work aims to determine the diversity and spatial genetic structure of two natural populations, referred to as MC I and MC II, of which 60 individuals were sampled, in Poço Bonito Biological Reserve, Lavras, Minas Gerais state. Results of 10 polymorphic isozyme loci indicated a high genetic diversity for the species (Ĥe= 0.428 and Ĥo = 0.570), with an mean number of alleles per locus of 2.0. Estimates of Cockerham's coancestry coefficients indicated an absence of intrapopulation (<img border=0 width=28 height=24 src="../../../../../../img/revistas/cerne/v17n2/a06car02.jpg" > or = -0.343) and interpopulation inbreeding (<img border=0 width=26 height=26 src="../../../../../../img/revistas/cerne/v17n2/a06car01.jpg" > or = -0.161), suggesting that on average populations are not endogamous. A high genetic divergence was found between populations (<img border=0 width=26 height=27 src="../../../../../../img/revistas/cerne/v17n2/a06car03.jpg"> = 13.5%), in comparison to most tropical species (<5%). Consequently, the estimated historical gene flow was low (<img border=0 width=26 height=27 src="../../../../../../img/revistas/cerne/v17n2/a06car04.jpg">m = 0.40). The analysis of spatial distribution of G. schottiana genotypes in MCI revealed a random distribution of genotypes. The high genetic diversity indices found suggest that the populations in question favor in situ genetic conservation, consequently favoring the conservation of riparian environments.

In the present work, we evaluated the occupation of the Córrego dos Bois sub-basin, in the municipality of Oliveira County, Minas Gerais State, in Brazil -based on it, it has been obtained land cover classes, defined areas of permanent preservation, identified the conflict among land use and environmental laws, and calculated environmental indicators.

-The aim of this work was to evaluate viability and DNA ploidy of seed of Melanoxylon brauna submitted or not to fast drying, along soaking. The seeds were dried followed by germination and quantification of DNA ploidy pattern. There was a gradual decrease in germination percentage with increases in temperature and drying time. The DNA ploidy of embryonic axes that were not submitted to artificial drying indicated the existence of nuclei 2C, 4C and 8C. However, 95% of the tested embrios had 2C DNA ploidy . The seeds that were subjected to rapid drying also exhibited the presence of nuclei 2C, 4C and 8C and showed no significant differences ( p > 0.05 ) compared to seeds that have not passed through drying. It is conclude that the seeds of Melanoxylon brauna submitted to different drying times and temperatures show a gradual decrease in the percentage of germination; embryonic axes subject or not to drying seeds have 2C, 4C and 8C nuclei and drying does not affect the cell cycle of cells in the embryo of the seed. Termos para indexação: ploidia, citometria de fluxo, secagem.

-The objective of this study was to partially characterize some genes involved in the desiccation tolerance of the embryonic axis of Melanoxylon brauna seeds subjected, or not, to oven fastdrying. Seeds were initially dried rapidly in an oven at 40 ºC, 50 ºC, 60 ºC, 70 ºC, and 80 °C, for 24, 48 and 72 h and then subjected to germination tests and moisture content determination. Degenerate primers were designed for 19 genes. The CDNA was used as a template for PCR amplifications using the degenerate primers, and the PCR products obtained were purified, cloned and sequenced. The seeds showed a gradual reduction in percent germination with increasing temperature and drying time. Nucleotide sequences of the cloned fragments related to genes CAT1, SPS1, Abi5, Transk and PM25 were obtained. The similarity analysis with the sequences deposited in databases revealed similarities with genes CAT1, SPS1, Transk and PM25 from other plant species. The nucleotide sequences obtained from the respective genes will be used for designing specific primers for gene expression analyses during seed germination in order to understand the causes for loss of physiological quality of Melanoxylon brauna seeds.Index terms: water, stress, drying, sequencing.Caracterização parcial de genes do eixo embrionário de sementes de Melanoxylon brauna Schott. (Leguminosae-Caesalpinioideae) RESUMO -O presente trabalho objetivou caracterizar parcialmente os genes envolvidos com a tolerância à dessecação do eixo embrionário de sementes de Melanoxylon brauna submetidas ou não à secagem rápida. As sementes foram submetidas à secagem rápida em estufa nas temperaturas de 40 ºC, 50 ºC, 60 ºC, 70 ºC e 80 ºC, nos tempos de 24, 48 e 72 h e, em seguida, submetidas ao teste de germinação e determinação do grau de umidade. Foram utilizados primers degenerados para 19 genes. Os produtos de PCR obtidos foram purificados, clonados no vetor pGEM-T Easy e sequenciados. As sementes apresentaram redução gradativa na porcentagem de germinação com o aumento da temperatura e tempo de secagem. Foram obtidas as sequências dos fragmentos clonados referentes aos genes CAT1, SPS1, ABI5, Transk e PM25. A comparação das sequências obtidas com sequências depositadas em bancos de dados revelou similaridade com os genes CAT1, SPS1, Transk e PM25 de outras espécies. As sequências de nucleotídeos obtidas dos respectivos genes servirão para a confecção de oligonucleotídeos específicos para posteriores estudos de expressão gênica durante a germinação de sementes de M. brauna submetidas à secagem, visando entender as causas da perda de qualidade fisiológica dessas sementes.Termos para indexação: água, secagem, sequenciamento, estresse.