Answer evaluation of irrigated rice genotypes exposed to herbicides of imidazolinone chemical group.

The red rice (Oryza sativa) co-exists with the cultivated rice in commercial farmings, becoming one of the main limiting factors for the yield increase in this crop, since this weed competes for the same resources. The rice crop is one of the most important in the world, being the main nutritious source for more than half of the world´s population. Genes for resistance to herbicides have become the best option for the control of this weed. Herbicides that inhibit the ALS enzyme, such as those from the imidazolinone chemical group, are commonly used for weed control in many crops. These ALS inhibitors are currently used for the control of red rice, which is known as Clearfield® technology. This work aimed to study the morphological features that can assist in identifying Only® herbicide tolerance in hydroponic bioassays, and introgression of ALS inhibitor herbicide tolerance genes in cultivars through artificial hybridizations. The rice cultivars used were BRS Sinuelo CL and Puitá INTA CL as imidazolinone herbicide tolerant, and the BRS Pampa, BRS Querência, BRS Atalanta and BRS Fronteira, as sensitive. The variable insertion of the first leaf can be considered an appropriate candidate for study because it discriminates more effectively the responses of different genetic constitutions. Taking in account the doses and periods of development, it can be recommended for use as a morphological marker. The concentration of herbicide that allows better discrimination between tolerant and sensitive genotypes is 25μg L-1 as described in the methodology for this bioassay. The results of this study show that F2 hybrids resulting from crosses between cultivars carrying the allele for herbicide tolerance to the imidazolinone class and conventional rice cultivars, are feasible, enabling the establishment of populations with desirable agronomic characteristics of herbicidetolerant rice, with higher ability to fight the red rice.O arroz vermelho (Oryza sativa) co-existe com o arroz cultivado em lavouras comerciais, sendo esse um dos principais entraves para o aumento da produtividade dessa cultura, já que essa invasora compete pelos mesmos recursos que as cultivares necessitam. A cultura do arroz é uma das mais importantes no mundo, considerada a principal fonte nutritiva para mais da metade da população mundial. Genes para resistência a herbicidas têm se tornado uma das opções mais utilizadas no mundo para o controle de invasoras, sendo que os herbicidas inibidores da enzima ALS, classe das imidazolinonas, são amplamente utilizados para o controle de plantas daninhas em diversas culturas. Esses inibidores de ALS são atualmente utilizados para o controle do arroz vermelho, sendo esta tecnologia denominada Clearfield®. Este trabalho objetivou o estudo de características morfológicas capazes de auxiliar na identificação de tolerância ao herbicida Only®, em bioensaio em condições hidropônicas, e a introgressão de genes de tolerância ao herbicida inibidor de ALS em cultivares, através de hibridações controladas. Foram utilizados as cultivares de arroz BRS Sinuelo CL e Puitá INTA CL como padrão tolerante aos herbicidas imidazolinonas, e as cultivares BRS Pampa, BRS Querência, BRS Fronteira e BRS Atalanta, como padrão sensível. A variável inserção da primeira folha pode ser considerada uma variável apropriada para estudos, pois discrimina de maneira mais eficiente as diferentes respostas das constituições genéticas frente às doses utilizadas e aos períodos de desenvolvimento, podendo ser indicada para ser utilizada como marcador morfológico. A concentração de herbicida que possibilita melhor discriminação entre genótipos tolerantes e sensíveis é 25μg L-1, conforme metodologia descrita para esse bioensaio. Os resultados desse estudo mostram que os híbridos F2, resultantes de cruzamentos entre cultivares portadores do alelo de tolerância ao herbicida da classe das imidazolinonas e cultivares de arroz irrigado convencionais, são viáveis, possibilitando o estabelecimento de populações de arroz irrigado tolerantes ao herbicida, com maior capacidade de combater o arroz vermelho e com características de interesse agronômico

Direct observations of galactic cosmic rays

The mysterious “radiation ... entering our atmosphere from above” discovered by Hess in 1912 is now known to be dominated by relativistic charged particles, mostly with energies in the GeV-range, but extending to energies higher by many orders of magnitude. As none of these particles can penetrate the earth’s atmosphere without interaction, detailed studies of their composition and energy spectra require observations with high-altitude balloons or spacecraft. This became possible only towards the middle of the 20th century. The direct measurements have now revealed much detail about the Galactic cosmic rays below 1015eV, but do not yet provide much overlap with the air-shower region of energies. A historic overview of the measurements is given, beginning with the realization that the majority of the cosmic rays are protons. The discovery and astrophysical significance of the heavier nuclei, and of the ultra-heavy nuclei beyond iron and up to the actinides, are then described, and measurements of the isotopic composition are discussed. Observations of the individual energy spectra are reviewed, and finally, the detection of electrons, positrons, and anti-protons in the cosmic rays, and the searches for exotic or unusual phenomena are summarized. Emphasis is given to the fact that all of these discoveries have become possible through the evolution of increasingly sophisticated detection techniques, a process that is continuing through the present time. The precise knowledge of the abundance distributions of the elements in the cosmic rays and of their isotopic composition permits a comparison with the “universal abundance scale” and provides strong constraints on the origin of the cosmic-ray material in the interstellar medium. “Clock-isotopes” reveal the time history of the particles. The shapes of the energy spectra of the individual cosmic-ray components are related to evolving ideas about particle acceleration and propagation in the Galaxy. In conclusion, prospects for future work are briefly discussed

Micropropagação do porta-enxerto de videira '420-A' Micropropagation of '420-A' grapevine rootstock

O objetivo deste trabalho foi estabelecer um protocolo para a micropropagação do porta-enxerto de videira 420-A. O estabelecimento das culturas foi realizado com segmento nodal, cuja fonte dos explantes foram brotações de estacas lenhosas armazenadas sob refrigeração. No cultivo inicial, foram testados: o efeito de 6-benzilaminopurina e cinetina nas concentrações de 0; 1; 5 e 10 &micro;M, diferentes meios de cultura (MS, NN e WPM) e diluições do meio básico (MS, MS/2, MS/4 e MS/8). Na fase de alongamento e multiplicação, os meios de cultura testados foram MS, MS/2, NN e WPM. No enraizamento, foram testados: o meio de cultura MS/2 sem e com carvão ativado (1gL-1). Na aclimatização, foram testados vermiculita, Plantmax® e casca de arroz carbonizada como substrato. A cinetina não apresentou efeito sobre a brotação e o crescimento dos segmentos nodais. Já o BAP promoveu um aumento no número de brotos por explante. O aumento na concentração de BAP reduziu o número de folhas emitidas por explante e aumentou os sintomas de vitrificação, sendo os melhores resultados obtidos com 1 &micro;M de BAP. No cultivo inicial, o meio de cultura MS, com a concentração normal de sais, permitiu o maior crescimento das brotações. As diluições do meio MS em 1/4 e 1/8 mostraram-se prejudiciais ao desenvolvimento do porta-enxerto '420-A', afetando o crescimento das brotações após o primeiro subcultivo. Durante a multiplicação o meio MS/2 foi o que proporcionou melhores resultados. O enraizamento ocorreu naturalmente durante a multiplicação, sendo desnecessário o uso de carvão ativado no meio de cultura. A aclimatização foi realizada com sucesso em câmara de nebulização, com substrato vermiculita (95,8%) e Plantmax® (87%). Conclui-se que o porta-enxerto '420-A' pode ser micropropagado pelo cultivo inicial de segmentos nodais em meio de cultura MS + 1 &micro;M de BAP, alongamento das brotações e multiplicação pelo seccionamento das mesmas em meio MS/2 e aclimatização em substrato vermiculita ou Plantmax®.<br>The objective of this work was to establish a protocol for the rootstock of 420-A micropropagation. The establishment of the cultures was accomplished with nodal segments, whose source of explants was the budding of woody stakes stored under refrigeration. In the initial cultivation were tested: the effect of 6-benzilaminopurine and kinetin with 0, 1, 5 and 10 &micro;M concentrations, different culture medium (MS, NN and WPM) and dilutions of the basic medium (MS, MS/2, MS/4 and MS/8). In the alongation and multiplication steps were tested the following culture medium: MS, MS/2, NN and WPM. In the rooting were tested: the MS/2 culture medium with or without activated coal (1gL-1). In the acclimatization were tested the substrate vermiculite, Plantmax and carbonized rice hulls. The kinetin didn't present effect on the budding and the growth of the nodal segments. BAP already promoted an increase in the number of sprouts per explant. The increase in the concentration of BAP reduced the number of leaves emitted by explant and increased the vitrification symptoms, being the best results obtained with 1 &micro;M of BAP. In the initial cultivation the MS medium culture with the normal concentration of salts allowed the largest growth of the buddings. The dilutions of the MS medium in &frac14; and 1/8 showed very harmful to the development of the rootstock '420-A', being quite harmed the growth of the shoots after the first subcultivation. During the multiplication the medium MS/2 showed more appropriate. The roots happened naturally during the multiplication, being unnecessary the use of activated coal in the culture medium. The acclimatization was accomplished with success in a misty camera, being obtained high survival rates in vermiculite (95,8%) and Plantmax® (87%). It is concluded that the rootstock '420-A' can be micropropagated by initial cultivation of nodal segments in a culture medium of MS+1&micro;M of BAP, multiplication by sectionalizing the shoots in MS/2 medium and acclimatization in vermiculite substratum or Plantmax®