Graziela Piveta

Superação de dormência na qualidade de sementes e mudas: influência na produção de Senna multijuga (L. C. Rich.) Irwin & Barneby

The objective of this work was to determine the physiological and sanitary quality of Senna multijuga seeds related to the methods of dormancy overcoming and the influence on the seedlings quality. The seeds had been submitted to the following methods :immersion in water fervent, the seeds had been immersed in water, at 100°C, until cooling for 24 hours; acid escarification, where the seeds had been immersed in sulfuric acid (H 2 SO 4 ) 90%, for 10 and 20 minutes, and control (without treatment). The tests of sanity, germination and tetrazolium had been carried through, and were evaluated the quality of the seedlings. For the germination of the evaluation an factorial project was used (4 X 2), with four methods of dormancy X two light periods, for substrate paper and vermiculite. The acid scarification consisted in the method most efficient for the dormancy of Senna multijuga seeds. Penicillium sp. and Aspergillus sp. they had for its increased incidence when the seed coast was damaged by the acid scarification for 20 minutes. The control of Fusarium spp. increases gradual with the increase of the time of sulfuric acid exposition.

Detecção e influência de Fusarium spp. na qualidade fisiológica de sementes de pepino

Este trabalho teve por objetivo isolar, identificar e selecionar isolado(s) de Fusarium spp. em sementes de pepino e verificar a sua influencia na qualidade fisiologica. Foram utilizados tres sublotes e os tratamentos consistiram em: testemunha absoluta; BDA + manitol - 0,8Mpa; BDA; BDA + manitol - 0,8Mpa + fungo; e BDA + fungo. A qualidade fisiologica foi avaliada atraves de testes em laboratorio e casa de vegetacao. Cinco isolados de Fusarium verticillioides foram identificados e a sua transmissao atraves das sementes para plantas nao foi possivel afirmar. A tecnica da restricao hidrica foi eficiente para proporcionar infeccao das sementes, sabendo que e o fungo influencia negativamente na qualidade fisiologica das sementes de pepino da cultivar Caipira.

Qualidade sanitária e fisiológica de sementes de Aroeira-Preta ( Lithraea molleoides ) submetidas a métodos de superação de dormência

O presente estudo teve como objetivo avaliar a qualidade fisiologica e sanitaria de sementes de Lithraea molleoides (Vell.) Engl. comparando diferentes metodos de superacao da dormencia. Os metodos de superacao da dormencia utilizados foram: escarificacao acida por 10, 15, 20 e 25 minutos; imersao em agua quente, com temperatura de 70, 80 e 90°C, ate resfriar por 24 horas, imersao em acido giberelico (GA3) na concentracao de 250 e 500 mg.L-1, por 24 e 48 horas; e imersao em nitrato de potassio (KNO3) por 24 e 48 horas. Foram realizadas avaliacoes de sanidade, germinacao e comprimento medio de plântulas. O delineamento experimental foi inteiramente casualizado, com quatro repeticoes de 25 sementes por tratamento. Os dados em percentagem foram transformados segundo arco sen√x/100 e submetidos a analise de variância. A comparacao das medias foi realizada atraves do teste de Tukey a 5 % de significância. Foi realizada analise de correlacao simples entre sementes mortas do teste de germinacao e os diferentes fungos identificados no teste de sanidade. No teste de sanidade, foram identificados com maior incidencia os fungos Rhizoctonia spp., Penicillium spp., Aspergillus spp., Alternaria spp., Chaetomium spp., Epicoccum spp. De uma maneira geral, a utilizacao da agua quente controlou a incidencia dos diferentes fungos e a utilizacao do acido giberelico proporcionou um aumento da incidencia dos diferentes patogenos. A maior porcentagem de germinacao foi observada quando se utilizou escarificacao acida por 20 minutos, imersao em agua quente a 70°C, GA3 (250 mg L-1 por 48 horas) e KNO3 por 48 horas.

Genetic variability suggests that three populations of Ceratocystis fimbriata are responsible for the Ceratocystis wilt epidemic on kiwifruit in Brazil

Ceratocystis fimbriata is a native, soilborne pathogen in South America that causes a lethal wilt disease on a broad range of economically important plants. Ceratocystis wilt on kiwifruit (Actinidia spp.) was first recognized in 2010 in the state of Rio Grande do Sul, Brazil. The genetic variation among kiwifruit isolates was analized to determine if a single introduced strain of the pathogen was responsible for the epidemic or if there was substantial genetic variation in the population, suggesting that the fungus was soilborne and indigenous to the region. We used 14 microsatellite (simple sequence repeat, SSR) markers to identify 18 genotypes of C. fimbriata among 76 isolates from eight kiwifruit farms. The 18 genotypes clustered into three groups based on UPGMA analysis of the microsatellite alleles. The largest group comprised 60 isolates of 11 closely-related microsatellite genotypes obtained from seven of the eight farms. These genotypes appeared to have originated from a single farm that had supplied cuttings for grafting to the other farms. The population of the pathogen from the farm that supplied the cuttings had the highest level of genotypic diversity and relatively high gene diversity, suggesting that this source population represented an indigenous, soilborne population. Phylogenetic analyses of the DNA sequences of the mating type locus (including portions of MAT1-1-2 and MAT1-2-1) placed the isolates into three groups, corresponding to the three microsatellite groups. Most of the isolates, including all the tested isolates from the farm that supplied the cuttings, had mating type gene sequences that were distinct from other Brazilian populations of C. fimbriata. A second group comprised isolates from one farm that had mating type gene sequences typical of Mata Atlântica (Rio de Janeiro and São Paulo) populations of C. fimbriata on Colocasia esculenta and Mangifera indica. Three farms purchased kiwifruit plants or rootstocks from commercial nurseries in Brazil as well as scions from the source farm, and some of the isolates from these farms were genetically similar to Eucalyptus isolates of C. fimbriata from Bahia and Minas Gerais, Brazil. The kiwifruit epidemic in Rio Grande do Sul is the southern-most report of C. fimbriata in Brazil, and the primary pathogen population on kiwifruit appears to be indigenous and originated from a single farm that distributed the pathogen in grafting material. In addition, commercial nursery stock was also implicated as sources of C. fimbriata genotypes. The disease is a major limiting factor for kiwifruit production in southern Brazil, and the results suggest that clean planting stock will be important to successful production.

Inoculation methods of Alternaria alternata and A. dauci in parsley seeds and their influence on the physiological quality

The objective of the study was to evaluate the effect of the association of Alternaria alternata and A. dauci on the physiologic quality of parsley seeds inoculated by two methods: conidia suspension and water restriction. For the inoculation with suspension, a solution containing 105 conidia of A. alternata, A. dauci and both species (A. alternata + A. dauci), was prepared in which the seeds remained for 30 minutes. For inoculation by water restriction, a PDA medium was prepared, supplemented with 33.1 g/L of manitol, in which the A. alternata, A. dauci and A. alternata + A. dauci colonies grew. The seeds remain on the plates for 48 hours. After the inoculation, the quality of the seeds was evaluated by testing in the laboratory and greenhouse. The parsley seeds had their physiological quality damaged by association with A. alternata and A. dauci under laboratory conditions, especially in relation to germination, first count germination, abnormal seedlings, percentage of dead seeds and the cold test.

Ocorrência de Ceratocystis fimbriata em Kiwi (Actinidia deliciosa) no sul do Brasil

In a routine inspection on a plantation of kiwi (Actinidia deliciosa) plants were found with wilt symptoms, internal browning and death of the stem tissues. Isolations from infected tissues and soil rhizosphere, allowed to obtain a culture of fungus with morphological characteristics similar to Ceratocystis fimbrita whose identification was confirmed based on the sequencing of the ITS region of rDNA. The pathogenicity test was conducted in Monty and Farroupilha varieties. It was found that the causal agent of the disease in kiwi belong to the C. fimbriata complex and to the group of Latin America and the isolates inoculated were pathogenic to two varieties tested.

QUALIDADE SANITÁRIA E FISIOLÓGICA DE Senna macranthera QUANDO SUBMETIDA A MÉTODOS DE SUPERAÇÃO DA DORMÊNCIA

Senna macranthera , better known as manduirana, belongs to the family of Caesalpiniaceae and occurs naturally in the region from the states of Parana to Rio Grande do Norte. It is a pioneer species, characteristic of secondary education. The objective of this study to determine the health and physiological quality of Senna macranthera seeds when subjected to methods of overcoming dormancy. The seeds were submitted to break dormancy by: acid scarification for 10, 15, 20 and 25 minutes; immersion in hot water with temperature of 70, 80 and 90°C by cooling for 24 hours; immersion in gibberellic acid (GA 3 ) at a concentration of 250 and 500 mg.L -1 , 24 and 48 hours; immersion in potassium nitrate (KNO 3 ) at a concentration of 0,2% for 24 and 48 hours. Then they were made the health tests, germination and tetrazolium. The experimental design was completely randomized with four replications of 25 seeds per treatment. The comparison of means between the different treatments to overcome seed dormancy was conducted by the Tukey test at level 5% significance. The main genera of fungi found associated with the seeds were Penicillium sp. and Aspergillus sp. The Senna macranthera seeds had higher germination rate when subjected to acid scarification for 15 and 20 minutes, hot water at 70°C; soaking in GA 3 250 mg.L -1 for 48 hours and KNO3 for 48 hours. The use of rapid tests, such as the tetrazolium test, proved inefficient, since there was an overestimation of seed vigor.

Formação continuada dos professores das escolas técnicas da Universidade Federal de Santa Maria

This article highlights the importance of the presence of teachers in continuing education courses, aiming to analyze the participation of teachers of Polytechnic and Technical Industrial - Ctism - Colleges of Federal University of Santa Maria - UFSM - in continuing education courses. For this, we conducted a quantitative survey and the data collected through a multiple choice questionnaire that was applied to teachers in these institutions. It was concluded that most teachers of Polytechnic and Ctism Colleges of UFSM participate in continuing education courses and institutions to receive this incentive. Still, teachers attend refresher courses in education, even those that are embedded in more technical areas. Key-words: professional development, technological education.

Qualidade fisiológica e tratamentos de sementes de cedrela fissilis procedentes do sul do Brasil

Os objetivos deste trabalho foram: avaliar a qualidade fisiologica de sementes de cedro (Cedrela fissilis), procedentes de localidades do sul do Brasil, atraves de testes de vigor e avaliar diferentes tratamentos nas sementes para controle de patogenos e para promocao da germinacao da especie. Para tanto, foram utilizadas seis amostras com procedencias dos Estados do Rio Grande do Sul, Santa Catarina e Parana, as quais foram submetidas a determinacao de teor de agua, teste de germinacao e primeira contagem, envelhecimento acelerado (testando periodos de exposicao as condicoes de envelhecimento), emergencia em viveiro e tratamento de sementes. Os tratamentos utilizados para controle de patogenos foram: testemunha (T0); fisico com calor seco a 70°C±3°C por 48 horas (T1); extrato aquoso de alho (Allium sativum) (T2); biologico a base de Trichoderma spp. - Agrotich Plus® (T3); e quimico com fungicida protetor Captan (T4). A germinacao variou de 56 a 87%; o periodo de 48 h sob temperatura de 41 °C foi o mais eficiente para estratificar as amostras em niveis de vigor; a emergencia variou de 51 a 88% e as variaveis de desempenho de plântulas analisadas conseguiram estratificar as amostras em niveis de vigor. Quanto ao tratamento de sementes, o calor seco e o tratamento a base de extrato de alho se mostram eficientes no controle de microrganismos em semente de cedro, sem prejuizos ao vigor destas.