Genetic diversity analysis among pigeonpea genotypes adapted to South American regions based on microsatellite markers.

The pigeonpea [Cajanus cajan (L) Millspaugh] is one of the most important perennial legume crops utilized in the food, fodder, soil conservation, crop-livestock integrated systems, reclaiming of degraded pastures and symbiotic nitrogen fixation. Microsatellite markers were used to estimate the genetic diversity of 77 pigeonpea genotypes selected from the germplasm collections at Embrapa Cattle-Southeast and, to evaluate their transferability to Phaseolus vulgaris and Vigna unguiculata species. The number of alleles per locus ranged from 2 to12, with an average of 5.1 alleles. The PIC values ranged from 0.11 to 0.80 (average 0.49) and the D values from 0.23 to 0.91 (average 0.58). The averages of observed and expected heterozygosity were 0.25 and 0.47, respectively, showing a deficit in heterozygosity. A model-based Bayesian approach implemented in the software STRUCTURE was used to assign genotypes into clusters. A dendrogram was constructed based on the modified Roger's genetic distances using a neighbor-joining method (NJ). A total of four clusters were assembled by STRUCTURE and a strong tendency of correspondence between the Bayesian clusters in the NJ tree was observed. The genetic distance ranged from 0.09 to 0.62 (average 0.37), showing a low genetic diversity in the pigeonpea genotypes. Transferability of pigeonpea-specific microsatellites revealed a cross-amplification and the presence of polymorphic alleles in P. vulgaris and V. unguiculata

Introdução, avaliação e melhoramento de plantas forrageiras tropicais no Brasil: novas propostas de Modus operandi.

Um exemplo de BAG e seus resultados; Dos BAGs aos projetos monoespecíficos; Um exemplo de projeto novo monoespecífico: o projeto Panicum no CNPGC; Proposta para a organização de uma rede de avaliação a nível nacional; Primeiras propostas de metodologia para avaliação de leguminosas.bitstream/item/104690/1/Introducao-avaliacao-e-melhoramento.pd

Development of microsatellite markers in Guineagrass (Panicum maximum Jacq.) and their transferability to other tropical forage grass species.

The Guineagrass (Panicum maximum Jacq.) is one of the most important tropical forage grasses, but genetic knowledge and tools regarding this species are still limited. Therefore, 20 novel polymorphic microsatellite markers were developed, validated, and employed in estimating genetic relationships among 25 P. maximum genotypes selected from a Brazilian germplasm collection. In addition, they were tested for cross-species amplification in four other forage grass species. The number of alleles observed for each locus ranged from 4 to 12 (average 6.7). The values of polymorphism information content (PIC) varied from 0.41 to 0.83 (average 0.61) and the discriminating power (D) ranged from 0.53 to 0.98 (average 0.72). Cross-amplification demonstrated the potential transferability of these microsatellites to four tropical forage grass species. Cluster analysis based on the unweighted pair group method revealed three distinct groups: two clusters consisted of P. maximum genotypes and a third cluster, consisted of the other tropical forage grass species. The data demonstrated that the microsatellites developed herein have potential for germplasm characterization and genetic diversity analysis in P. maximum and other forage grass species

Atomic layering at the liquid silicon surface: a first- principles simulation

We simulate the liquid silicon surface with first-principles molecular dynamics in a slab geometry. We find that the atom-density profile presents a pronounced layering, similar to those observed in low-temperature liquid metals like Ga and Hg. The depth-dependent pair correlation function shows that the effect originates from directional bonding of Si atoms at the surface, and propagates into the bulk. The layering has no major effects in the electronic and dynamical properties of the system, that are very similar to those of bulk liquid Si. To our knowledge, this is the first study of a liquid surface by first-principles molecular dynamics.Comment: 4 pages, 4 figures, submitted to PR

The size of Wiman-Valiron disks

Wiman-Valiron theory and results of Macintyre about "flat regions" describe the asymptotic behavior of entire functions in certain disks around points of maximum modulus. We estimate the size of these disks for Macintyre's theory from above and below.Comment: 20 page

Discovery of Prognostic Markers for Early-Stage High-Grade Serous Ovarian Cancer by Maldi-Imaging

With regard to relapse and survival, early-stage high-grade serous ovarian (HGSOC) patients comprise a heterogeneous group and there is no clear consensus on first-line treatment. Currently, no prognostic markers are available for risk assessment by standard targeted immunohistochemistry and novel approaches are urgently required. Here, we applied MALDI-imaging mass spectrometry (MALDI-IMS), a new method to identify distinct mass profiles including protein signatures on paraffin-embedded tissue sections. In search of prognostic biomarker candidates, we compared proteomic profiles of primary tumor sections from early-stage HGSOC patients with either recurrent (RD) or non-recurrent disease (N = 4; each group) as a proof of concept study. In total, MALDI-IMS analysis resulted in 7537 spectra from the malignant tumor areas. Using receiver operating characteristic (ROC) analysis, 151 peptides were able to discriminate between patients with RD and non-RD (AUC > 0.6 or 0.7). These results confirm that in using IMS, we could identify new candidates to predict clinical outcome and treatment extent for patients with early-stage HGSOC

Seleção de progênies de Brachiaria decumbens utilizando diferentes intensidades de seleção.

As pastagens constituem no sistema pecuário Brasileiro de corte, a principal fonte de alimentação adotada para a produção animal. A utilização das mesmas cultivares comerciais no entanto, promoveu a formação de extensos monocultivos resultando em grandes riscos fitotécnicos e fitossanitários. Com base nessas informações, o presente trabalho teve por objetivo avaliar caracteres agronômicos e nutricionais de uma população de híbridos intraespecíficos de Brachiaria decumbens, a fim de predizer os ganhos de seleção para cada característica. Para isso, uma população de irmãos germanos de B. decumbens foi obtida por meio do cruzamento entre 75 híbridos sexuais com a cultivar apomítica Basilisk

Reaction rates for Neutron Capture Reactions to C-, N- and O-isotopes to the neutron rich side of stability

The reaction rates of neutron capture reactions on light nuclei are important for reliably simulating nucleosynthesis in a variety of stellar scenarios. Neutron capture reaction rates on neutron-rich C-, N-, and O-isotopes are calculated in the framework of a hybrid compound and direct capture model. The results are tabulated and compared with the results of previous calculations as well as with experimental results.Comment: 33 pages (uses revtex) and 9 postscript figures, accepted for publication in Phys. Rev.

Melhoramento de Brachiaria ruziziensis tetraploide sexual na Embrapa: métodos e avanços.

O presente trabalho apresenta os resultados obtidos com a experimentação inicial e o melhoramento de Brachiaria ruziziensis tetraploide e sexual na Embrapa Gado de Corte. Os objetivos são identificar as melhores genitoras sexuais em cruzamentos ao acaso com genótipos apomíticos e sexuais, identificar os melhores híbridos desses cruzamentos e compor uma população sexual tetraploide para fins de seleção intrapopulacional. A avaliação de 312 indivíduos de quatro progênies (R30, R44, R46 e R50) revelou que a melhor genitora em cruzamento quando foram considerados os caracteres de produção forrageira e de valor nutritivo foi a R50. Com base no valor genotípico predito para os indiví- duos em múltiplos cortes foi possível selecionar os melhores indivíduos das progênies, dos quais, os apomíticos são cultivares em potencial. Na composição da população de melhoramento intraespecífica sexual, as genitoras foram cruzadas ao acaso em área protegida de contamina- ção de pólen externo e realizada a colheita individual de sementes. Das sementes colhidas de plantas individuais, no período de maior sobreposição de produção, foram obtidas 60 progênies para compor o primeiro ciclo de melhoramento intrapopulacional em B. ruziziensis. Os próximos passos para o melhoramento de B. ruziziensis e obtenção de híbridos interespecíficos apomíticos e superiores são descritos.bitstream/item/71808/1/DOC194.pd

Fungal endophytes of Panicum maximum and Pennisetum purpureum: isolation, identification, and determination of antifungal potential.

This study aimed to isolate and identify endophytic fungi from the forage grass P. maximum and evaluate their ability to inhibit the growth of plant pathogenic fungi. One sample from P. purpureum grass was also included. Surface disinfected stem fragments were used for endophytic fungal isolation. One hundred and twenty-six endophytic fungi were isolated, of which 118 were from P. maximum and eight from P. purpureum. Morphological characteristics and internal transcribed spacer (ITS) and 18S (NS) sequence comparisons identified most isolated endophytic fungi as belonging to the phylum Ascomycota, with Sarocladium being the dominant genus. The isolates were subjected to in vitro antagonism tests against pathogenic fungi, and 31 endophytic fungi inhibited the growth of Bipolaris maydis, Penicillium expansum, and Sclerotinia minor. The results expand our knowledge of the diversity of endophytes associated with tropical grasses and suggest that they may represent new sources of antifungal metabolites for biocontrol and biotechnological purposes