ABSTRACT Family farmers are important in the on-farm conservation of cassava, since they maintain distinct ethnovarieties in their plantations. This research aimed to analyze ethnobotanical aspects and the genetic diversity of cassava ethnovarieties maintained by farmers in the Baixada Cuiabana, Mato Grosso state, Brazil, in the Rio dos Couros community. A semi-structured questionnaire was applied for the ethnobotanical characterization of the cassava ethnovarieties. Subsequently, young leaves of the cassava plants were collected for DNA extraction. The ethnobotanical survey identified 29 cassava ethnovarieties, with the most cultivated ones being Pão, Amarelona and Cacau. The farmers characterize the cassavas with the following characteristics: palatability, pulp color, origin and similarities with animals and vegetables. Genetic relationships were observed among the ethnovarieties and five groups were identified, with formation of subgroups. In these groupings, it is possible to highlight the isolation of the Matrinxã, Paraguainha and Broto Roxo ethnovarieties as the most genetically divergent ones.

RESUMO Agricultores familiares são importantes na conservação on farm de mandioca, visto que mantêm em suas plantações distintas etnovariedades. Objetivou-se analisar aspectos etnobotânicos e a diversidade genética de etnovariedades de mandioca mantidas por agricultores da Baixada Cuiabana, Mato Grosso, na comunidade Rio dos Couros. Um questionário semiestruturado foi aplicado para a caracterização etnobotânica das etnovariedades de mandioca. Posteriormente, folhas jovens das mandiocas foram coletadas para extração de DNA. O levantamento etnobotânico identificou 29 etnovariedades, sendo as mais cultivadas a Pão, Amarelona e Cacau. Os agricultores caracterizam as mandiocas com os seguintes caracteres: palatabilidade, cor da polpa, origem e semelhanças com animais e vegetais. Observaram-se relações genéticas entre as etnovariedades e cinco grupos foram identificados, com formação de subgrupos. Nesses agrupamentos, foi possível destacar o isolamento das etnovariedades Matrinxã, Paraguainha e Broto Roxo como as mais divergentes geneticamente.

RESUMO: O pau-de-balsa é amplamente utilizado nas indústrias náutica, aeronáutica e de energia eólica devido à sua baixa densidade. No estado de Mato Grosso, produtores especulativos de balsa têm estabelecido plantios sem conhecimento sólido da cultura usando mudas não padronizadas e não selecionadas. Pesquisas são necessárias para melhorar o cultivo de balsa sob condições brasileiras para melhor explorar este recurso. O presente estudo teve como objetivo avaliar a eficiência do instrumento Pilodyn para a determinação indireta da densidade básica da madeira (DBM) de balsa. Vinte árvores de 12 anos de idade cultivadas em Alta Floresta, Mato Grosso, foram avaliadas com o instrumento Pilodyn nas faces norte e sul do tronco, na base e a 1,30 e 3,10 m do solo. Discos de madeira foram posteriormente coletados dos locais sondados e o DBM determinado de acordo com o método de imersão em água. Os dados foram submetidos ao teste de normalidade Shapiro-Wilk seguido de análise de variância e análise de correlação de Pearson com α=0,05. Os valores de DBM da balsa diminuiu da base em direção ao topo da árvore, enquanto a profundidade de penetração do Pilodyn foi inversamente proporcional. A correlação entre a profundidade de penetração do Pilodyn e o DBM foi fraca na base do tronco (R2=0,46), mas forte (R2=0,72) nos pontos de 1,30 e 3,10 m. O método Pilodyn foi suficientemente confiável que permitiu o desenvolvimento de uma equação para a determinação indireta do DBM do pau-de-balsa considerando o valor da profundidade de penetração a 1,30 m como uma das variáveis.

ABSTRACT: Balsa wood is used widely in the nautical, aeronautical and wind-energy industries because of its low-density and high-resistance. In the Brazilian state of Mato Grosso, speculative producers with little knowledge of the culture have established balsa plantations using non-standardized and non-selected seedlings. In this sense, research is needed to improve balsa cultivation under Brazilian conditions to better explore the resource. The present study evaluated the efficiency of the Pilodyn instrument for the indirect determination of the basic wood density (BWD) of balsa. Twenty 12-year old balsa trees cultivated in Alta Floresta, Mato Grosso, were probed with the Pilodyn instrument on both north and south faces of the trunk at the base and at 1.30 and 3.10 m from the ground. Wood discs were subsequently collected from the probed sites and BWD determined according to the water-immersion method. Data were submitted to the Shapiro-Wilk normality test followed by analysis of variance and Pearson’s correlation analysis with α=0.05. The BWD of balsa decreased in the direction from the base to the top of the tree. The penetration depth of the Pilodyn probe was inversely proportional to BWD with a correlation that was strong (R2=0.72) at heights of 1.30 and 3.10 m but considered weak (R2=0.46) at the base of the trunk. The reliability of the Pilodyn method was sufficient to allow the development of a linear equation that could be applied for the indirect determination of the BWD of balsa based on the penetration depth of the Pilodyn probe assessed at 1.30 m from the ground.

ABSTRACT Bertholletia excelsa (Brazil nut) is the only representative of the Bertholletia genus, but presents great phenotypic variability. The objective of this study was to characterize the fruits, seeds and crude oil of Brazil nuts from the state of Mato Grosso, Brazil. Fruit and seeds from adult trees were collected at the municipalities of Alta Floresta, Cotriguaçu, Itaúba and Juína. Physical characteristics, yield and composition of the seeds, as well as crude oil characteristics were evaluated. The fruits produced in Itaúba were the smallest and had the lowest number of seeds, while those from Juína presented larger size and mass. The nuts produced in Itaúba had the lowest mean unit mass and ten-seed mass values. The seeds produced in Juína presented higher lipid content and lower ash content. The selenium content of the nuts was higher in Cotriguaçu. There were no significant differences in fruit peel thickness, yield and protein content of the nuts or characteristics of the crude oil.

ABSTRACT Spondias mombin L. is a fruit species native to the Amazon with great marketing potential. The aim of this study was to examine the meiotic behavior and pollen viability of S. mombin. Flower buds at various developmental stages were collected for analyses of pollen viability, in vitro germination, and meiotic behavior. S. mombin is diploid with 2n = 2x = 30 chromosomes. Meiosis showed to be regular, with only 13.3% of cells with abnormal division. A high meiotic index was found: 96.5%. Pollen viability did not differ between male (96.3%) and bisexual (96.7%) flowers, and the overall mean of viable pollen was considered high (96.5%). Pollen germination occurred in all tested media, with the treatment containing 20% sucrose and 50 mg mL‒1 boric acid being the most suitable. The highest pollen germination means occurred after 36 h of incubation. The obtained information can be used in the planning and implementation of commercial crops of the species.