Cultura de tecidos e análise fitoquímica de Arachis repens HANDRO.

Os representantes do gênero Arachis são conhecidos como amendoim, e suas sementes possuem grande quantidade de óleos e proteínas, podendo ser consumidas cruas. A espécie mais cultivada do gênero é Arachis hypogaea, que possui grande importância comercial. Outras espécies são também utilizadas para controle das ervas daninhas e cobertura do solo, assim como ornamentais e na alimentação. Arachis repens, popularmente conhecida como grama amendoim, é utilizada como planta ornamental, na formação de pastagens, como forragem e para cobertura do solo em substituição a várias espécies comuns de grama. Diversas substâncias bioativas têm sido identificadas em A. hypogaea. Contudo, estas substâncias ainda não foram descritas em outras espécies do gênero. O objetivo deste trabalho foi o estabelecimento de sistemas de cultivo in vitro para Arachis repens, visando à micropropagação e à análise comparativa da produção de resveratrol em extratos alcoólicos dos materiais produzidos in vitro, em comparação com as plantas in vivo. Segmentos nodais, internodais e foliares foram excisados de plantas in vitro e inoculados em meio MS suplementado com diferentes concentrações de BAP, TDZ, AIA e KIN, utilizados isoladamente ou em combinação. Os explantes apresentaram respostas distintas de acordo com o regulador de crescimento utilizado. Na presença de BAP foi observada a formação de calos compactos, com formação de brotos em diferentes taxas. Na presença de TDZ, segmentos nodais e internodais formaram calos compactos em todas as concentrações. Segmentos nodais cultivados na presença de diferentes concentrações de AIA em combinação com KIN apresentaram a formação de calogênese. Foi também realizada uma avaliação da atividade antioxidante e a presença de fenóis totais em extratos de diferentes materiais in vivo e produzidos in vitro. Nas análises por meio de CLAE, foi possível detectar a presença de resveratrol tanto nos materiais in vivo, quanto os produzidos in vitro. Dessa forma, o trabalho forneceu resultados preliminares sobre as possibilidades de utilização de A. repens para a produção de metabólitos especiais.

Manual de identificação de doenças e fungos em Arachis spp.

Plantas do gênero Arachis são conhecidas da humanidade há cerca de 8 mil anos. O termo amendoim é originário de mãdu?bi, da língua tupi. As espécies forrageiras são comumente chamadas de amendoim forrageiro ou até grama amendoim no Brasil. A espécie Arachis pintoi Krapovickas & Gregory, exclusivamente forrageira, vem sendo cada vez mais usada para pastejo de animais devido à quantidade de proteínas e biomassa produzida, além do uso na jardinagem e paisagismo em áreas urbanas e rurais. Essa preferência pela espécie baseia-se em longo histórico de sucesso em outros países para a finalidade a que se destina. Outras espécies encontradas nesse gênero e utilizadas em programas de melhoramento genético de amendoim forrageiro para a produção de proteína a baixo custo são Arachis repens Handro, Arachis glabrata Benth., Arachis valsii Miotto, Arachis appressipila Krapov & W. C. Greg. e Arachis helodes Mart. ex Krapov. & Rigoni. Algumas doenças fúngicas afetam A. pintoi quando este se encontra estabelecido no campo ou em viveiro, casas de vegetação ou telado. No entanto, fungos que ocorrem nas sementes têm importante papel na disseminação de doença a longa distância e no estabelecimento de plantas de amendoim forrageiro no campo seja para multiplicação ou para uso definitivo. O conhecimento da diversidade de fungos fitopatogênicos e saprófitas que ocorrem em Arachis spp. é de fundamental relevância para os trabalhos de diagnósticos, para a emissão de certificados fitossanitários de origem, certificados fitossanitários, ações de defesa vegetal, segurança no trabalho e para o controle de doenças. Desse modo, foi elaborado este Manual que, além de ser um guia ilustrado para a identificação de doenças, também traz informações de como isolar e caracterizar taxonomicamente os fungos associados ao amendoim forrageiro. Esta publicação é destinada aos produtores, estudantes, professores, pesquisadores, técnicos e todos aqueles que se interessam pela cultura do amendoim forrageiro nos campos e nas cidades, em atividades produtivas, educacionais e de extensão.

Genetic diversity analysis in the section Caulorrhizae (genus Arachis) using microsatellite markers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Novel polymorphic microsatellite markers in section Caulorrhizae (Arachis, Fabaceae)

This work reports the characterization of 11 polymorphic microsatellite loci in section Caulorrhizae. The primer pairs were designed from Arachis pintoi and showed full transferability to Arachis repens species. These new markers were used to evaluate the genetic diversity in germplasm (accessions and cultivars) of section Caulorrhizae. This new set of markers detected greater gene diversity than morphological and molecular markers such as AFLP (amplified fragment length polymorphism) and RAPD (rapid analysis of polymorphic DNA) previously used in this germplasm.

Genetic variation and phylogenetic relationships based on RAPD analysis in section Caulorrhizae, genus Arachis (Leguminosae)

Wild Arachis germplasm includes potential forage species, such as the rhizomatous Arachis glabrata and the stoloniferous A. pinto and A. repens. Commercial cultivars of A. pintoi have already been released in Australia and in several Latin American countries, and most of these cultivars were derived from a single accession of A. pintoi (GK 12787). Arachis repens is less productive as a forage plant than is A. pintoi. However, it can be crossed with A. pintoi, and thus has good potential as germplasm for the improvement of A. pintoi. Arachis repens is also used as an ornamental plant and ground cover. Many new accessions of these two stoloniferous species are now available, and they harbor significant genetic variability beyond that available in the few older accessions, previously available. Therefore, these new accessions need to be conserved, documented and considered in terms of their potential for crop improvement and direct commercial use. Sixty-four accessions of this new germplasm were analyzed using RAPD analysis. Most of the accessions of A. repens grouped together into a clearly distinct group. In general, the accessions from the distinct valleys of the Jequitinhonha, Sao Francisco and Parana rivers did not group together, suggesting there is not a tight relation between dispersion by rivers and the geographic distribution of genetic variation in these species.

Investigação de efeitos alelopáticos de espécies do gênero Arachis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Genetic diversity of the forage peanut in the Jequitinhonha, São Francisco, and Paranã River valleys of Brazil.

Arachis pintoi and A. repens are legumes with a high forage value that are used to feed ruminants in consortium systems. Not only do they increase the persistence and quality of pastures, they are also used for ornamental and green cover. The objective of this study was to analyze microsatellite markers in order to access the genetic diversity of 65 forage peanut germplasm accessions in the section Caulorrhizae of the genus Arachis in the Jequitinhonha, São Francisco and Paranã River valleys of Brazil. Fifty-seven accessions of A. pintoi and eight of A. repens were analyzed using 17 microsatellites, and the observed heterozygosity (HO), expected heterozygosity (HE), number of alleles per locus, discriminatory power, and polymorphism information content were all estimated. Ten loci (58.8%) were polymorphic, and 125 alleles were found in total. The HE ranged from 0.30 to 0.94, and HO values ranged from 0.03 to 0.88. By using Bayesian analysis, the accessions were genetically differentiated into three gene pools. Neither the unweighted pair group method with arithmetic mean nor a neighbor-joining analysis clustered samples into species, origin, or collection area. These results reveal a very weak genetic structure that does not form defined clusters, and that there is a high degree of similarity between the two species.

Variability and genetic parameters of chlorophyll content in forage peanut genotypes using the SPAD index.

This study aimed to verify the existence of variability and to estimate genetic parameters for chlorophyll content in forage peanut genotypes.

Heritability and genetic correlations of mineral macronutrients in the biomass and leaves of forage peanut.

This study aimed to estimate heritability coefficients and genotypic correlations of mineral macronutrients in forage peanut.

Análise de crescimento em amendoinzeiro (Arachis hypogaea L.) submetido à matocompetição

Foram verificados os efeitos de diferentes períodos de controle e convivência de plantas daninhas (0; 14; 28; 42; 56; 70; 84 e 98 dias) na cultura do amendoinzeiro (Arachis hypogaea L.) em Moji-Guaçu (SP). As principais espécies invasoras da área experimental foram: Acanthospermum australe (Loef.) O. Kuntz, Waltheria indica L., Borreria alata DC., Richardia scabra L., Rhynchelytrum repens (Nees) Stapf. et Hubb. e Diodia teres Walt. de maneira geral, durante quase todo o ciclo, a espécie de maior importância relativa foi A. australe, sendo suplantada por outras espécies apenas na colheita, quando já estava encerrando seu ciclo de desenvolvimento. O período inicial de controle das plantas daninhas, além de reduzir a densidade da comunidade infestante, diminuiu sua riqueza em espécies e alterou a importância relativa das populações. A matocompetição resultou na redução do crescimento do amendoinzeiro, principalmente a partir de 42 dias de convivência, afetando a altura das plantas, a área foliar, o índice de área foliar e o acúmulo epígeo de matéria seca. Não foram afetados os números de ramos e de folíolos por planta, nem a qualidade dos grãos e o vigor das sementes do amendoim. A produção de frutos foi reduzida ao redor de 31,5% em decorrência da interferência das plantas daninhas. O período total de prevenção da interferência na produção foi de 14 dias e o período anterior à interferência foi de 70 dias.

Isolation and characterization of microsatellite loci from the forage species Arachis pintoi (Genus Arachis)

Arachis pintoi is an alternative to forage production in the tropics. Its germplasm comprises more than 150 accessions, that could be used to improve it. Our objective was the isolation and characterization of microsatellite loci in A. pintoi to be used to molecular evaluation of this germplasm and of A. repens (section Caulorrhizae). Seven loci were analyzed using five accessions of A. repens and 20 accessions of A. pintoi. The high variation found makes clear the high potential of this marker in genetic studies in these species. The developed markers showed total transferability to A. repens.

The analysis of large scale data taken from the world groundnut (Arachis hypogaea L.) germplasm collection I. Two-way quantitative data

Data associated with germplasm collections are typically large and multivariate with a considerable number of descriptors measured on each of many accessions. Pattern analysis methods of clustering and ordination have been identified as techniques for statistically evaluating the available diversity in germplasm data. While used in many studies, the approaches have not dealt explicitly with the computational consequences of large data sets (i.e. greater than 5000 accessions). To consider the application of these techniques to germplasm evaluation data, 11328 accessions of groundnut (Arachis hypogaea L) from the International Research Institute for the Semi-Arid Tropics, Andhra Pradesh, India were examined. Data for nine quantitative descriptors measured in the rainy and post-rainy growing seasons were used. The ordination technique of principal component analysis was used to reduce the dimensionality of the germplasm data. The identification of phenotypically similar groups of accessions within large scale data via the computationally intensive hierarchical clustering techniques was not feasible and non-hierarchical techniques had to be used. Finite mixture models that maximise the likelihood of an accession belonging to a cluster were used to cluster the accessions in this collection. The patterns of response for the different growing seasons were found to be highly correlated. However, in relating the results to passport and other characterisation and evaluation descriptors, the observed patterns did not appear to be related to taxonomy or any other well known characteristics of groundnut.

The analysis of large scale data taken from the world groundnut (Arachis hypogaea L.) germplasm collection. II. Two-way data with mixed data types

As a sequel to a paper that dealt with the analysis of two-way quantitative data in large germplasm collections, this paper presents analytical methods appropriate for two-way data matrices consisting of mixed data types, namely, ordered multicategory and quantitative data types. While various pattern analysis techniques have been identified as suitable for analysis of the mixed data types which occur in germplasm collections, the clustering and ordination methods used often can not deal explicitly with the computational consequences of large data sets (i.e. greater than 5000 accessions) with incomplete information. However, it is shown that the ordination technique of principal component analysis and the mixture maximum likelihood method of clustering can be employed to achieve such analyses. Germplasm evaluation data for 11436 accessions of groundnut (Arachis hypogaea L.) from the International Research Institute of the Semi-Arid Tropics, Andhra Pradesh, India were examined. Data for nine quantitative descriptors measured in the post-rainy season and five ordered multicategory descriptors were used. Pattern analysis results generally indicated that the accessions could be distinguished into four regions along the continuum of growth habit (or plant erectness). Interpretation of accession membership in these regions was found to be consistent with taxonomic information, such as subspecies. Each growth habit region contained accessions from three of the most common groundnut botanical varieties. This implies that within each of the habit types there is the full range of expression for the other descriptors used in the analysis. Using these types of insights, the patterns of variability in germplasm collections can provide scientists with valuable information for their plant improvement programs.

Pattern analysis of the diversity of morphological plant attributes and herbage yield in a world collection of white clover (Trifolium repens L.) germplasm characterised in a summer moisture stress environment of Australia

Information on the variation available for different plant attributes has enabled germplasm collections to be effectively utilised in plant breeding. A world sourced collection of white clover germplasm has been developed at the White Clover Resource Centre at Glen Innes, New South Wales. This collection of 439 accessions was characterised under field conditions as a preliminary study of the genotypic variation for morphological attributes; stolon density, stolon branching, number of nodes. number of rooted nodes, stolon thickness, internode length, leaf length, plant height and plant spread, together with seasonal herbage yield. Characterisation was conducted on different batches of germplasm (subsets of accessions taken from the complete collection) over a period of five years. Inclusion of two check cultivars, Haifa and Huia, in each batch enabled adjustment of the characterisation data for year effects and attribute-by-year interaction effects. The component of variance for seasonal herbage yield among batches was large relative to that for accessions. Accession-by-experiment and accession-by-season interactions for herbage yield were not detected. Accession mean repeatability for herbage yield across seasons was intermediate (0.453). The components of genotypic variance among accessions for all attributes, except plant height, were larger than their respective standard errors. The estimates of accession mean repeatability for the attributes ranged from low (0.277 for plant height) to intermediate (0.544 for internode length). Multivariate techniques of clustering and ordination were used to investigate the diversity present among the accessions in the collection. Both cluster analysis and principal component analysis suggested that seven groups of accessions existed. It was also proposed from the pattern analysis results that accessions from a group characterised by large leaves, tall plants and thick stolons could be crossed with accessions from a group that had above average stolon density and stolon branching. This material could produce breeding populations to be used in recurrent selection for the development of white clover cultivars for dryland summer moisture stress environments in Australia. The germplasm collection was also found to be deficient in genotypes with high stolon density, high number of branches high number of rooted nodes and large leaves. This warrants addition of new germplasm accessions possessing these characteristics to the present germplasm collection.

Expression, Purification and Characterization of Peanut (Arachis hypogaea) Agglutinin (PNA) from Baculovirus Infected Insect Cells

Peanut (Arachis hypogaea) seed lectin, PNA is widely used to identify tumor specific antigen (T-antigen), Gal beta 1-3GalNAc on the eukaryotic cell surface. The functional amino acid coding region of a cDNA clone, pBSH-PN was PCR amplified and cloned downstream of the polyhedrin promoter in the Autographa californica nucleopolyhedrovirus (AcNPV) based transfer vector pVL1393. Co-transfection of Spodoptera frugiperda cells (Sf9) with the transfer vector, pAcPNA and AcRP6 (a recombinant AcNPV having B-gal downstream of the polyhedrin promoter) DNAs produced a recombinant virus, AcPNA which expresses PNA. Infection of suspension culture of Sf9 cells with plaque purified AcPNA produced as much as 9.8 mg PNA per liter (2.0 x 10(6) cells/ml) of serum-free medium. Intracellularly expressed protein (re-PNA) was purified to apparent homogeneity by affinity chromatography using ECD-Sepharose. Polyclonal antibodies against natural PNA (n-PNA) crossreacted with re-PNA. The subunit molecular weight (30 kDa), hemagglutination activity, and carbohydrate specificity of re-PNA were found to be identical to that of n-PNA, thus confirming the abundant production of a functionally active protein in the baculovirus expression system.