Resumo A savana brasileira, também conhecida como Cerrado, é caracterizada por sua grande diversidade de fitofisionomias e detém a maior diversidade de espécies e nível de endemismo entre as savanas mundiais. Contudo, devido principalmente às atividades agropecuárias essa vasta vegetação está entre as mais degradadas, apresentando elevadas taxas de extinção. Entre as espécies atualmente presentes na “lista vermelha” encontra-se a endêmica Gymnopogon doellii, uma gramínea cuja distribuição é extremamente restrita a algumas poucas áreas. No Distrito Federal e arredores apenas uma população é conhecida, localizada dentro dos limites do Parque Nacional de Brasília. Neste estudo levantamos informações relevantes relacionadas a biologia dessa população de G. doellii, como sua área de distribuição, variabilidade genética e características de germinação. Mudas a partir de suas cariopses foram produzidas em casa de vegetação, plantadas em diferentes fisionomias do Cerrado, incluindo áreas degradadas, e suas taxas de sobrevivência e desempenho fisiológico acompanhados por quase quatro anos. A população apresenta baixa variabilidade genética. As mudas apresentaram altas taxas de sobrevivência (> 25%), padrões de crescimento similar aos indivíduos selvagens e produziram cariopses viáveis. Recomendamos o plantio de indivíduos de G. doellii tanto para sua conservação in situ como para recuperação de áreas degradadas do Cerrado.

Abstract The Brazilian savanna, regionally known as Cerrado, is characterized by a great diversity of physiognomies and holds the highest species diversity and level of endemism among world savannas. However, due mainly to agribusiness, this vegetation is among the most threatened ones, currently presenting alarming rates of extinction. Among the species present in the “red list” we find the endemic Gymnopogon doellii, a grass whose distribution is restricted to a few sites. In the Federal District and surroundings, for example, only one population, with scattered subpopulations, is known, within the limits of the Brasilia National Park. By this study we raised information related to the biology of G. doellii, as population size and distribution, genetic variability and germination characteristics. Besides, we produced seedlings in greenhouse, planted in different physiognomies of the Cerrado and followed them for almost four years to check for their survival, growth and fruiting under natural conditions. Seedlings transplanted to the field presented high rates of recruitment (> 25%), growth patterns similar to wild plants and produced viable caryopses. We recommend transplanting of individuals of G. doellii for both in situ conservation as well as for the revegetation of degraded areas of the Cerrado.

Abstract ‘IAC Sempre Verde’ is a medium-seeded runner-type peanut highly resistant to late leaf spot and rust, the main diseases in peanut cultivation in Brazil. The newly released cultivar showed remarkable yield advantage over controls when diseases were not controlled and represents the first possibility for peanut cultivation under “Organic” management.

Abstract Peanut (Arachis hypogaea L.) is an important oilseed crop and food legume that is highly susceptible to biotic and abiotic factors. Wild Arachis species represent useful genetic resources because of their resistance to pests and diseases. In particular, understanding the affinity between B-genome species is important for broadening the genetic base of A. hypogaea (AABB genome), since only one population of A. ipaënsis is known, and relatively few other species have been described. Therefore, we aimed to determine the genomic affinity between A. ipaënsis and A. williamsii by developing hybrids. Microsatellite markers verified the hybrid status, and chromosome pairing and pollen viability results revealed that the species share high genomic affinity. Additionally, the presence of dyads detected in sporad and pollen analyses indicated the production of 2n gametes. These results will be useful for performing evolutionary studies and developing strategies for introgression programs to improve the B genome of A. hypogaea.

Abstract Peanut is a crop of the Kayabi tribe, inhabiting the Xingu Indigenous Park, Brazil. Morphological analysis of Xingu accessions showed variation exceeding that described for cultivated peanuts. This raised questions as to the origin of the Xingu accessions: are they derived from different species, or is their diversity a result of different evolutionary and selection processes? To answer these questions, cytogenetic and genotyping analyses were conducted. The karyotypes of Xingu accessions analyzed are very similar to each other, to an A. hypogaea subsp. fastigiata accession and to the wild allotetraploid A. monticola. The accessions share the number and general morphology of the chromosomes; DAPI+ bands; 5S and 45S rDNA loci distribution and a high genomic affinity with A. duranensis and A. ipaënsis genomic probes. However, the number of CMA3+ bands differs from those determined for A. hypogaea and A. monticola, which are also different from each other. SNP genotyping grouped all Arachis allotetraploids into four taxonomic groups: Xingu accessions were closer to A. monticola and A. hypogaea subsp. hypogaea. Our data suggests that the morphological diversity within these accessions is not associated with a different origin and can be attributed to morphological plasticity and different selection by the Indian tribes.

Abstract BRS 425 is a high-oleic runner peanut cultivar related to wild ancestral parents, partially resistant to early and late leaf spot and spotted wilt. It is large-seeded and contains 46% oil. BRS 425 is adapted to the main peanut-producing regions of Brazil.

Development of leaf spots resistant runner peanut cultivars is one of the major demands in Brazil. In the 2009/10 crop season, 12 pre-breeding progenies (LPM) were selected out of 380 plants of an interspecific BC1F3 population for leaf spots resistance and agronomic traits. In the 2010/11, the 12 LPMs were evaluated for leaf spots resistance, without fungicide sprays. The recurrent parent (susceptible control) and all LPMs were susceptible; partial resistant segregating plants were selected. Some progenies had yield, pod and seed shape similar to the control. The 12, and the 5 LPMs selected in the 2011/12 and 2012/13 crop seasons, respectively, were evaluated under appropriate disease management. Differences were detected for pod yield and weight of 100 seeds. Seed/pod weight ratio, oil content and oleic/linoleic ratio were similar to thecontrol. Individual plants were selected for pod yield and market quality. Variability detected in the first backcross generation for partial resistance and agronomic traits will be useful.