Caracterização genética de caprinos Marota no Estado do Piauí por meio de microssatélites de DNA.

Os caprinos possuem um importante papel para a agricultura do Nordeste, concentrando-se nesta região o maior plantel da espécie no Brasil. O Estado do Piauí possui rebanhos de alguns grupos genéticos adaptados ao semi-árido e que se encontram em risco de desaparecimento. Este trabalho teve o objetivo de caracterizar a raça caprina naturalizada Marota por meio de marcadores de microssatélite, dando suporte a futuras pesquisas de melhoramento ou conservação de recursos genéticos. Os animais avaliados pertencem ao Núcleo de Conservação da Embrapa Meio-Norte e estão em risco de desaparecimento. O DNA extraído foi amplificado mediante a reação em cadeia polimerase (PCR), em multiplex e genotipados através do programa Fragment Profile (Amershan Biosystem). A freqüência alélica (FA) e a heterosigozidade media observada (H) foram calculadas através do programa TFPGA (Miller, 1997). Todos os loci analisados foram considerados informativos (H>0,5) segundo Ott (1992). Os Loci ILSTS011, CSRDS247 e HSC mostraram alelos exclusivos para a população, quando comparado com a literatura, refletindo possível variação genética entre esta população de caprinos Marota e outras populações nativas européias. O número de alelos observado demonstra haver diversidade dentro da população, não havendo indicativos de perda de diversidade dentro do rebanho de conservação

Production and nutritive value of piatã grass and hybrid sorghum at different cutting ages.

The influence of cutting age on production and nutritive value of piatã grass (Brachiaria brizantha cv. BRS Piatã) and hybrid sorghum (Sorghum spp. cv. BRS 801) under an integrated croplivestock system was evaluated. The trial was carried out at the Embrapa Beef Cattle (20º27' S; 54º37' W) in Campo Grande, Mato Grosso do Sul State, Brazil, between April and October 2009. Experimental design consisted of randomized blocks with four replicates. Treatments were distributed across a split-plot design, which included three production systems (single piatã grass; single hybrid sorghum; mixed cultivation of sorghum and piatã grass). Half-plots consisted of three forage ages at harvest (with 70, 90 and 110 days after seeding). Variables included agronomical characteristics, productivity and nutrition value. Regardless of the evaluated systems, cutting age affected agronomical characteristics and in vitro digestibility of organic matter (IVDOM). Production was highest (4,048 kg ha-1) within the integrated system. Regardless of cutting age, monoculture sorghum had the highest crude protein level. Results showed that integrated sorghum and piatã grasses were an asset for forage productivity. Forages had higher values in crude protein and in in vitro digestibility of organic matter on the 70th day after seeding.Título em português: Produtividade e valor nutritivo de capim-piatã e sorgo de corte e pastejo em diferentes idades de corte

Irrigated rice sowing periods based on simulated grain yield.

This study aimed to establish the sowing periods with lower climatic risk for irrigated rice cultivation in the State of Rio Grande do Sul, Brazil, using the grain yield simulated by the SimulArroz which is an eco-physiological model based in processes that also simulates the development and the growth of the crop. The simulated grain yields were normalized for each of the four groups of cultivars, referenced as Relative Yield (YRel), considering the values of Reference Yield (YRef). The YRef considered was equal to the 80 percentile for the cultivars of groups 1 and 2 (Very short and Short cycle, respectively), and to the 90 percentile, for the cultivars of groups 3 and 4 (Medium and Long cycle, respectively). A successful year was when the YRel value was equal to or greater than 60% of YRef. These years were used to classify the climatic risk levels of 20% (80% success), 30% (70% success) and 40% (60% success). The preferential sowing periods for the four cultivar groups, at three levels of climatic risk, were established for all counties of the State of Rio Grande do Sul. The results indicated that the beginning of sowing occurs, depending on the group of cultivars, on September 1st or September 11th. On the other hand, the final sowing date varies with the group of cultivars and the level of risk involved, being December 20th the last sowing date for group 1 (Very short cycle). It is concluded that the SimulArroz model is appropriate to define the sowing periods of irrigated rice in Rio Grande do Sul considering grain yield, cycle of the cultivars and level of climatic risk

Genetic diversity analysis of mangaba (Hancornia speciosa Gomes), an exotic braxilian tropical species.

Twenty genotypes from natural population of mangaba located in Itaporanga D’Ajuda (Sergipe state - Brazil) were subjected to analysis using RAPD markers. Polymorphism, genetic diversity and structure parameters were determined to characterize the differences between plants. 60 DNA fragments were generated by 10 primers, 85% of which were polymorphic. Results show a quantitative genetic diversity value of 0.35 and a Shannon index of 0.46 in the population. The similarity among the specimens according to Jaccard’s coefficient ranged from 0.36 to 0.87. Using cluster analysis it was possible to indentify five groups. Three individuals also stand out since they presented significant divergence from the groups. The PCoA formed four groups, with three of the groups isolated from the others. This investigation showed that genetic diversity was relatively large among these individuals. In addition, the results demonstrated that RAPD markers are a useful tool for evaluating the genetic diversity and relationships among mangaba

Avaliação da variabilidade do teor de óleo de matrizes de pinhão manso (Jatropha curcas L.).

O objetivo deste trabalho foi quantificar a variabilidade do teor de óleo e o progresso genético com a seleção de matrizes de pinhão manso, em unidade de observação localizada no município de Ariquemes- RO

Changes in cattle herd composition and its implications on greenhouse gases emissions in Mato Grosso do Sul State between 2010 and 2014.

Cattle ranching is a major agricultural activity in Central Brazil and it plays a major economic role in Mato Grosso do Sul State. In the last few years, local agricultural development has been influenced by other agro-industries, mainly sugar cane and eucalyptus forestry, expanding over grazing areas, causing herd displacements but alsoleading to changes on local production systems. Herd numbersshow a tendency to decrease, while beef production keeps stable.This means improvements on individual husbandry techniques as wellas a general re-arrangement of herd structure. This can have important consequences on greenhouse gases (GHG) emissions from the sector inthe area. In this context, the goal of this study was to explore the implications of changes on cattle herd size and structure as well as land use change on GHG emissions per unit beef produced per unit of area used for cattle grazing in Mato Grosso do Sul State