Paulo Sérgio Nascimento Lopes

Estádio de maturação dos frutos e fatores relacionados aos aspectos nutritivos e de textura da polpa de pequi (Caryocar brasiliense Camb.)

The experiment was carried out with the purpose to obtain information about changes in the constituents responsible for nutritive and texture traits of pequi pulp related with harvest time and types of freezing. Fruits were collected in the tree before natural fall, in the ground after natural fall and in the ground three days after natural fall. In each harvest time, while one batch of the putamens was frozen in liquid nitrogen and afterwards stored in a freezer, another batch was frozen directly in the freezer. After six months the following analyses were performed in the pulp: contents of proteins, total carotenoid, b-carotene, licopene, vitamin A and lipids (nutritive characters); content of cellulose, hemicelluloses, total pectin, total and bound calcium, activity of polygalacturonase (PG) and pectinmethilesterase (PME) of the cell wall. The contents of pigments, lipids, proteins and activity of PG were the highest in the most advanced stages of maturation of fruits. On the other hand the content of cellulose decreased with the advanced stages of maturation whiles the content of hemicelluloses, total and bound calcium were not affected at the stages of maturation of the fruits. The types of freezing affected the contents of pigments; higher in the pulp frozen in liquid nitrogen; and the activity of PG was higher in the pulp frozen directly in the freezer. The fruits collected in the tree showed the lowest eating quality as judged by their lowest contents of pigments, protein and lipids. The results indicate that the most appropriate harvest time to higher quality of pequi fruits is after natural fall.

Caracterização do ataque da broca dos frutos do pequizeiro

The extractivism of pequi fruits (Caryocar brasiliense Camb.) (Caryocaraceae) is an important option of income, food and employment for the populations living in the savannah regions all over Brazil. However, the natural supply of those fruit is endangered by a great deal of factors, among those stands out a serious pest, Carmenta sp. (Lepidoptera: Sesiidae) making them unsuitable for consumption. The present study aimed to know some characteristics of the responsible insect as well as the way of attacking pequi fruits, damage caused and characteristic symptoms. This work was performed through the analysis of previously collected pequi fruits, both on the plant and soil in the type savannah vegetation in Montes Claros county, Northern Minas and Itumirim, Southern Minas, in Minas Gerais State. In the former county were harvested fruits between 80 - 120 days after anthesis (DAA), while in the last one in two times, 45 and 90 DAA. In each county, collect time and site (plant or soil) were collected 50 fruits for analysis. The evaluated characteristics were: longitudinal and transversal diameter, percentage of damaged fruits, number of worm per fruit and number of chrysalides per fruit. After the analysis of those characteristics, the insects developmental stages were recorded and documented photographycally as to length, coloration and morphology as well as attack symptoms. From this work, we can conclude that the pequi fruit lepidoborer can provoke damage to yield higher than 50 %, destroying all the inside of the fruits. The youngest fruits are the most attacked, being commom to find a single worm in its inside.

Caracterização física, físico-química, enzimática e de parede celular em diferentes estádios de desenvolvimento da fruta de figueira

With the objective of evaluating the physical, physical-chemical, enzymic and cell wall characterization during the different developmental stages of the fig tree fruits under irrigation in Northern Minas Gerais, the present work was developed during the 2001/2002 cropping cycle in the Unidade de Producao Fruticola da Escola Agrotecnica Federal de Salinas (Fruit Growing Unit of the Federal Agrotechnical School of Salinas (Eafsal), town of Salinas. Plants of two years and a half after transplanting and with twelve well developed primary branches (pernadas = the first strong branches of a tree) and 2.5x1.5 m spacing were utilized in this experiment. The design applied was completely randomized with two replicates and a total of 40 marked plants. The data collected were concerning 2001/2002 cropping cycle for the June-pruned plants. Evaluated during the different developmental stages of fig tree fruits activity of the enzimes, chemical composition, physical evaluate, neutral sugars and cell wall components. As polyphenoloxidase and peroxidase activity was decreasing, polygalacturonase activity increased throughout the development of the fruits. The fruits reached harvest point for industry and in natura consumption at 30 and 75 days from the differentiation of the buds in syconium, respectively. A significant increase took place in the contents of total soluble solids, total soluble and reducing sugars during the development of the fruit. Both pH and TTA ranged very little during fruit development. The average diameter of the fruits was always inferior to the average length, reaching 51.99 mm and 59.18 mm, respectively at 75 days. The average weight of 53.23 g was reached at 75 days. Predominating neutral sugars were galactose, arabinose and xylose whereas fucose, mannose and glucose and rhamnose were those present in smaller amount in the cell wall during the different developmental stages of the fruits. With the maturation of the fruits, there was a reduction of the chief components of pectic polysaccharides (galactose, arabinose and rhamnose), whilst the components of the hemicellulose fraction (xylose, glucose and mannose) tended to increase. Cellulose solubilization and fall in the contents of hemicellulose took place from 60 days when the fruit already in the physiological maturity, starts softening process, as related with pectin solubilization by the higher activity of the pectinnemethylesterase and polygalacturonase enzymes.

Efeito do AIB sobre a qualidade e fitossanidade dos alporques de influência da Caryocar brasiliense Camb (caryocaraceae)

The aim of this study was to test the influence of indol butiric acid (IBA) at four levels (0, 500, 1000, and 2000 ppm) to obtain healthy air layering of Caryocar brasiliense Camb (Caryocaraceae). In addition, we also observed the direct effect of this hormone on the success of leaf gall induction by Eurytoma sp. (Hymenoptera: Eurytomidae), and its indirect effect on galling insect parasitoids. A complete randomized design was used, with three replicates of each plot containing two air layering, and five treatments: 1) no girdling, 2) girdled + 0ppm IBA; 3) girdled + 500ppm IBA; 4) girdled + 1000ppm IBA, 5) girdled + 2000ppm IBA. The rates of air layering rooting, root/air layering, largest root length/air layering, callus formation and girdled shoots survival were not influenced by the different concentrations of IBA (p> 0.05). Furthermore, the number of the parasitoid Quadrastichus sp. (Hymenoptera: Eulophidae) and external morphological traits of the gall induced by Eurytoma sp. were not influenced by the different treatments. However, a positive relationship was found between IBA concentration and galls successfully induced, and between the number of adults of the galling Eurytoma sp. and its major parasitoid, Sycophila sp. (Hymenoptera: Eurytomidae) with 2.000ppm of IBA. These data indicate that the galling insect may select plant modules or plants with higher hormone concentration and that IBA may play a role in gall induction. Due to the low success of this hormone in the asexual propagation of C. brasiliense more studies are needed as this plant is one of the most important species in the Brazilian woodland savanna biome. Further studies are also needed to address hormone role in gall formation and its indirect effect on the community of associated parasitoids.

Poda e sistemas de condução na produção de figos verdes

The objective of the work was to verify the effect of pruning time and conduction system on growth, yield, and quality of the fig tree fruit grown in the northern Minas Gerais region, under irrigation. The design utilized was randomized blocks with four replicates, and the treatments arranged in a 4x2 factorial scheme, taking as factors pruning times (June, September, December and March) and conduction system (with lopping and without lopping). In each plot, made up of three useful plants, data concerning the cropping cycles of 2000/2001 and 2001/2002 were collected. No interaction between the factors pruning time and conduction system was verified. There were yield differences between pruning times; the March- and June-pruned plants presented higher yields. There were no yield differences between the conduction systems. Different pruning times and conduction systems did not affect quality of fig tree fruit and contents of total soluble solids, pH, total titrable acidity, total sugars, glucose, sucrose and starch.

Fruit maturation and in vitro germination of macaw palm embryos

Acrocomia aculeata (macaw palm) is oil producing palm tree with significant agro-industrial potential. Seed dormancy in palm species may be due to embryo immaturity, which could result from delayed embryogenesis. We evaluated the correspondence between the visual characteristics of maturing fruits and their physiological aspects and the in vitro germination capacity of the embryos. 11 fruit bunches in different stages of maturity were collected and classified in terms of the degree of maturation of the endosperm, the color of the exocarp, and the occurrence of abscission. The water and oil contents of the mesocarp and seed were determined, and lipids and proteins were identified through histochemical analyses of the mesocarp, endosperm, and embryo. The embryos from each fruit bunch were cultivated in vitro in 75% Murashige and Skoog (1962) media with added organic compounds. The water contents of the seeds varied from 71.2 to 21.1% among the different stages of fruit ripening and were related to the visual markers of fruit maturation (exocarp color ranging from dark green to brown). Lipid accumulation in the mesocarp occurred later than in the endosperm, and only occurred in fruits from bunches showing signs of abscission. Embryos from bunches in different stages of maturation showed similar germinative capacities, as well as similar patterns of lipid and protein storage. Embryogenesis in A. aculeata is precocious, and the embryos of immature fruits can be utilized for in vitro cultivation. Keywords : Acrocomia aculeata , embryo culture, embryogenesis, water content, oil content African Journal of Biotechnology Vol. 12(5), pp. 446-452

A new spectrophotometric method for determining the enzymatic activity of endo-β-mannanase in seeds

O objetivo deste trabalho foi desenvolver um novo metodo espectrofotometrico, de elevada sensibilidade, eficiente e de facil execucao para determinar a atividade enzimatica da endo-β-mananase em sementes. O metodo espectrofotometrico foi otimizado e aplicado em amostras de sementes de Butia capitata para determinar a localizacao da atividade enzimatica em diferentes partes das sementes. O metodo consiste em extrair a enzima da semente e utiliza-la para hidrolisar o galactomanano Locust Bean Gum. Os acucares redutores formados reagem com a hidrazida acida p-hidroxibenzoico e sao quantificados por espectrofotometria na regiao do visivel. O metodo otimizado e validado apresentou baixos limites de quantificacao para o acucar redutor formado (0,6 µg de manose) e atividade da endo-β-mananase (1 mU). Apenas 5 mg de sementes em germinacao sao necessarias para executar o metodo.

Relação entre o conhecimento local, atributos químicos e físicos do solo e uso das terras

The knowledge of farmers about the use of land can assist in soils survels. This study was conducted on the Fazenda Americana, located in northwester Minas Gerais State, Brazil, to relate the local knowledge of the environments to soil chemical and physical attributes and to the Land Use Capacity System, with an Agrarian reform focus. Based on the local knowledge seven environments were identified: baixa, vereda, chapada, tabuleiro, carrasco, tabuleiro misto and espigao (terms roughly translatable as: lowland, palm swamp, plateau, tableland, tall shrubland, mixed tableland and range top land). The local knowledge of environments is closely related with the Land Use Capability Classes, and represents a tool for the partitioning of land for Agrarian reform.

Saturação por bases no crescimento inicial e na produção de flavonóides totais da fava-d'anta

With the purpose of studying the effect of levels of base saturation upon the growth and total flavonoids production of Dimorphandra mollis cultivated on a soil originally under Savana of Minas Gerais State, Brazil, an experiment was conducted at the Universidade Federal de Minas Gerais, between October/2003 and February/2004. The experiment followed a completely randomized design with five values of base saturation (V%): 10 (natural saturation), 25; 40; 55 and 70%, and six replicates. The increase of base saturation led to a decrease of Dimorphandra mollis growth, and did not influence the total flavonoids plant concentration.

Superação da dormência de sementes de umbuzeiro (Spondias tuberosa, Arr. Câm.) utilizando diferentes métodos

Several fruits of native species of semi-arid region have great potential for commercialization, and among them there is the Spondias tuberosa. However, commercial cultivation of this species is limited by the difficulty of obtaining seedlings mainly depending on the dormancy of its seeds. Thus, the purpose of this study was to evaluate the seeds overcoming dormancy methods of Spondias Tuberosa to promote an increase in the rates of germination, uniformity and vigor of the seedlings. Two experiments were independently conducted. The treatments of the first experiments were: test, immersion of the seeds in water for 24 hours, immersion of the seeds in solution of gibberellic acid 1000 mg / L for 24 hours, scarification of seeds with sulfuric acid PA for 10 minutes and mechanical scarification of seeds. In the second experiment, the treatments consisted of planting the seeds with 0, 30, 60, 90, 120, 150, 180 and 210 days of storage in paper bags under laboratory conditions, at an average temperature of 22.5° C and relative humidity of 65%. In the first study it was found that there was a significant effect of the methods to seeds overcoming dormancy, concluding that the mechanical scarification is the best treatment, with an average germination rate in 60 days after planting 26.6%. In the second experiment, storage positively influenced the germination of seeds and seedlings vigor. The best results for uniformity and germination percentage (83%) were obtained between 120 and 210 days of seeds storage, while for the length and fresh weight of root, between 120 and 150 days.