Clonagem in vitro via cultivo de meristema de pimenteira-do-reino: assepsia e estabelecimento de cultura.

A cultura da pimenteira-do-reino tem grande importância econômica no Brasil, mas há restrição de cultivo devido a vulnerabilidade genética da mesma à doença fusariose causada pelo fungo Fusarium solani f. sp.piperis. A forma de propagação vegetativa é disseminadora da doença e métodos de controle da doença são pouco exitosos. Programas de melhoramento em execução visam gerar híbridos resistentes à doença em questão, além de agregar características agronômicas competitivas. Doenças viróticas ocorrem em todas as cultivares e há necessidades de limpeza clonal dessas cultivares via cultura de tecidos. Há dificuldades de obtenção de explantes assépticos devido a problemas de bactérias e fungos endógenos. Este trabalho teve por objetivo o estabelecimento de meristema (<1,0 mm) in vitro para a limpeza clonal via micropropagação. A partir de plantas originadas de estacas, meristemas (apicais e laterais) foram excisados a partir segmentos nodais e apicais, previamente submetidos a diferentes tratamentos de assepsia. Os meristemas foram inoculados em meio básico de cultura MS suplementado com BAP 0,5 mg.L-1 e AIA 0,2 mg.L-1. As respostas dos meristemas das diferentes cultivares foram avaliadas quanto a oxidação e contaminação, e os explantes verdes foram transferidos para meios frescos visando a diferenciação de brotos. Dos meristemas de nove cultivares utilizadas, apenas alguns das cultivares IAÇARÁ e genótipo 239 apresentaram desenvolvimento satisfatório. As demais não desenvolveram, oxidaram e/ ou sofreram contaminação por fungos e/ ou bactérias

Amostragem sequencial e marcadores de microssatélites na avaliação da qualidade genética em lotes de sementes de milho.

Edição dos Resumos do XIII Congresso Brasileiro de Sementes, Gramado, RS, set. 2003

Pair approximation for a model of vertical and horizontal transmission of parasites.

We apply Stochastic Dynamics method for a differential equations model, proposed by Marc Lipsitch and collaborators (Proc. R. Soc. Lond. B 260, 321, 1995), for which the transmission dynamics of parasites occurs from a parent to its offspring (vertical transmission), and by contact with infected host (horizontal transmission). Herpes, Hepatitis and AIDS are examples of diseases for which both horizontal and vertical transmission occur simultaneously during the virus spreading. Understanding the role of each type of transmission in the infection prevalence on a susceptible host population may provide some information about the factors that contribute for the eradication and/or control of those diseases. We present a pair mean-field approximation obtained from the master equation of the model. The pair approximation is formed by the differential equations of the susceptible and infected population densities and the differential equations of pairs that contribute to the former ones. In terms of the model parameters, we obtain the conditions that lead to the disease eradication, and set up the phase diagram based on the local stability analysis of fixed points. We also perform Monte Carlo simulations of the model on complete graphs and Erdös-Rényi graphs in order to investigate the influence of population size and neighborhood on the previous mean-field results; by this way, we also expect to evaluate the contribution of vertical and horizontal transmission on the elimination of parasite. Pair Approximation for a Model of Vertical and Horizontal Transmission of Parasites

Inv21p12q22del21q22 and intellectual disability

Chromosomal rearrangements are common in humans. Pericentric inversions are among the most frequent aberrations (1-2%). Most inversions are balanced and do not cause problems in carriers unless one of the breakpoints disrupts important functional genes, has near submicroscopic copy number variants or hosts "cryptic" complex chromosomal rearrangements. Pericentric inversions can lead to imbalance in offspring. Less than 3% of Down syndrome patients have duplication as a result of parental pericentric inversion of chromosome 21. We report a family with an apparently balanced pericentric inversion of chromosome 21. The proband, a 23-year-old female was referred for prenatal diagnosis at 16weeks gestation because of increased nuchal translucency. She has a familial history of Down's syndrome and moderate intellectual disability, a personal history of four spontaneous abortions and learning difficulties. Peripheral blood and amniotic fluid samples were collected to perform proband's and fetus' cytogenetic analyses. Additionally, another six family members were evaluated and cytogenetic analysis was performed. Complementary FISH and MLPA studies were carried out. An apparent balanced chromosome 21 pericentric inversion was observed in four family members, two revealed a recombinant chromosome 21 with partial trisomy, and one a full trisomy 21 with an inverted chromosome 21. Array CGH analysis was performed in the mother and the brother's proband. MLPA and aCGH studies identified a deletion of about 1.7Mb on the long arm of inverted chromosome 21q22.11. We believe the cause of the intellectual disability/learning difficulties observed in the members with the inversion is related to this deletion. The recombinant chromosome 21 has a partial trisomy including the DSCR with no deletion. The risk for carriers of having a child with multiple malformations/intellectual disability is about 30% depending on whether and how this rearrangement interferes with meiosis

Breeding sorghum for grain, forage and bioenergy in Brazil.

ABSTRACT - Sorghum is a versatile crop used for energy production, human and animal feedings, and raw material for industry. The grain sorghum is the fifth most important cereal worldwide, and Brazil is one of the top 10 sorghum producers. In the last 40 years, the sorghum grain yield in Brazil has increased to 32.70 kg ha-1 year -1. Although this clear evolution, much remains to be done, and sorghum breeders in Brazil still face several challenges. This review discusses the main characteristics of sorghum genetics and breeding, aiming for sorghum improvement for food, fodder, feed, and fuel uses. Herein will be highlighted essential topics related to the genetic control of the main interest traits; conventional sorghum breeding; the development of sorghum lines and hybrids; the use of male-sterility in sorghum breeding; the implication of genotypes-by-environments interaction in sorghum, the use of genome-wide association studies, and genomic prediction to maximize the efficiency of the sorghum breeding programs. RESUMO - O sorgo é uma cultura bastante versátil, sendo usada para a produção de energia, alimentação humana e animal, assim como matéria-prima para a indústria. Globalmente, o sorgo granífero é o quinto cereal de maior importância, e o Brasil é um dos dez maiores produtores de sorgo. Nos últimos 40 anos, a produtividade nacional de grãos de sorgo aumentou a uma taxa de 32,70 kg ha-1 ano-1. Embora essa clara evolução, ainda se tem muito a ser feito e diversos são os desafios enfrentados pelos melhoristas de sorgo no Brasil. Esta revisão discute os principais pontos da genética e melhoramento do sorgo, visando a produção de alimentos, forragem, ração e combustível. Serão destacados tópicos relacionados ao controle genético das principais características de interesse em sorgo; melhoramento convencional de sorgo; desenvolvimento de linhagens e híbridos em sorgo; o uso da machoesterilidade no melhoramento de sorgo; implicações da interação genótipos por ambientes; aplicação da associação genômica ampla e predição genômica para maximizar a eficiência dos programas de melhoramento de sorgo

Quality of soybean seeds with different lignin content obtained from desiccated plants.

Made available in DSpace on 2019-07-31T01:13:23Z (GMT). No. of bitstreams: 1 5421177751PB.pdf: 3517277 bytes, checksum: c85c7538c959ed3a24621b47f433a5bf (MD5) Previous issue date: 2019bitstream/item/199970/1/5421-17775-1-PB.pd

Desempenho de cultivares de mandioca no nordeste brasileiro.

bitstream/item/75032/1/Cot-121.pd

Habituação de novilhas Zebuínas no pré-parto para entrar na sala de ordenha: avaliação qualitativa.

bitstream/item/222495/1/ISABEL-Bol-365.pd