Édila Vilela de Resende Von Pinho

Bioestimulante e fertilizante associados ao tratamento de sementes de milho

The corn crop is very technological and this productive system absorbs all possible innovations to improve the yield, nevertheless some care should be taken concerning the addition of new chemicals to the seeds. The objective of this study was to evaluate the effect of seed treatment, with the biostimulant Stimulate ® as well with the liquid fertilizer Cellerate ® at 6 months before sowing and in the pre- sowing, on the physiological quality of seeds, on corn yield. Experiments were performed at the Federal University of Lavras, MG, Brazil in 2005, at field and laboratory level with a corn hybrid (GNZ 2004) and with a corn line (L57). The treatments used for corn assays were: witness (without chemicals); 5 mL.kg -1 Stimulate®; 5 and 10 mL.kg -1 Cellerate®. The seed physiological quality was accessed by germination, EVI, cold test and above and under ground dry mass of plantlets and by the analysis of the enzymes esterase, superoxide dismutase, malate dehydrogenase, alcohol dehydrogenase, catalase and a-amylase. The laboratory experiments were carried out in a complete randomized design with four replications. The a randomized block design was used of hybrid and line corn field with four replicates in a 4 x 2 factorial with the time and the compounds for seed treatment being the factors. In this assay plant and spike height, number

Effects of different drying rates on the physiological quality of Coffea canephora Pierre seeds

Desiccation tolerance in seeds depends on the species, development stage and drying conditions, especially the water removal rate. Coffea seeds are considered of intermediate performance, because they tolerate relative dehydration compared to orthodox seeds and are sensitive to low temperatures. The objective of this study was to verify the effect of different drying rates on the viability and storability of Coffea canephora seeds. A complete randomized experimental design was used, in a factorial 3 x 5 x 2 design, with three drying rates (fast, intermediate and slow), five final mean water contents after drying (51, 42, 33, 22 and 15 %) and two storage temperatures (10 and 20°C). The germination and seed vigor assessments, using radicle protrusion, cotyledon leaf opening, seedling emergence and emergence speed index, were performed shortly after drying and after two and four months storage. It was observed that with reduction in the water content there was reduction in the germination values and seed vigor, for all the drying rates. The greatest reductions in physiological quality occurred when the seeds were dried quickly and the best results were obtained at the intermediate drying rate. There was an effect of drying rate and storage temperature on the physiological quality of the seeds, and lower germination and vigor values were observed in seeds with lower water content stored at 20°C. C. canephora seeds were tolerant to desiccation down to 15 % water content and can be stored for four months at 10°C. A temperature of 20oC can be used to store C. canephora seeds, as long as the water content is not reduced to values below 22 % water content.

Influência do potássio e da calagem na composição química, qualidade fisiológica e na atividade enzimática de sementes de soja

A composicao quimica das sementes pode ser influenciada por fatores geneticos, ambientais e pela disponibilidade de nutrientes no solo durante a producao e, como consequencia, terem o seu vigor afetado. O potassio pode influenciar a atividade de varias enzimas presentes nas plantas, necessarias em varias reacoes envolvidas na utilizacao de energia, sintese de amido, metabolismo do nitrogenio e respiracao. Avaliou-se o efeito da adubacao potassica e da calagem na composicao quimica, qualidade fisiologica e na atividade de enzimas de sementes de soja. A pesquisa foi desenvolvida nos laboratorios de analises e biotecnologia de sementes do Departamento de Agricultura e no Laboratorio de Producao Vegetal do Departamento de Ciencias dos Alimentos da Universidade Federal de Lavras (UFLA). Em sementes de soja do cultivar Msoy 8001, produzidas sob 2 niveis de saturacao por base (48% e 85%) e quatro doses de K2O por hectare (0, 50, 100 e 200 kg), foram avaliados teores de oleo e proteina, germinacao, envelhecimento acelerado e atividade das enzimas envolvidas nos processos de germinacao e deterioracao de sementes. A adubacao potassica nao afeta a germinacao e o vigor das sementes, enquanto a elevacao da saturacao por base, proporciona maior vigor de sementes de soja. Ha aumento no teor de oleo e reducao no teor de proteina em sementes de soja a medida que a dose de K2O e aumentada. Ocorre aumento de teor de proteinas em sementes de soja, produzidas sob maiores niveis de saturacao por base. A atividade das enzimas piruvato quinase, esterase e alcool desidrogenase em sementes de soja e afetada pela concentracao de potassio e saturacao por base no solo.

Qualidade fisiológica de sementes de milho, feijão, soja e alface na presença de extrato de tiririca

(tiririca) e perene e de dificil controle. Os orgaos subterrâneosdessa ciperacea produzem inibidores capazes de interferir na germinacao e no crescimento deplântulas e de plantas de varias especies, fenomeno chamado de alelopatia. A inibicao na germinacaode sementes pode estar associada a interferencia de substâncias alelopaticas na atividade deenzimas chaves no processo de germinacao. Nesse trabalho foi avaliada a qualidade fisiologicaassim como a atividade de enzimas envolvidas no processo de germinacao em sementes de milho,feijao, soja e alface submetidas ao extrato de bulbos de tiririca. As sementes foram germinadas emsubstrato contendo extrato de bulbos de tiririca, nas concentracoes de 10 g L

Época de colheita e secagem na qualidade de sementes de pimenta Habanero Yellow

As pimentas constituem um dos principais produtos da olericultura brasileira. O interesse das industrias por especies picantes, como a pimenta Habanero, tem crescido a cada ano, sobretudo para a producao de molhos e preparados desidratados, o que aumentou a demanda no mercado por sementes de qualidade. O autor teve, atraves desta pesquisa, por objetivo avaliar os efeitos das epocas de colheita das sementes e da secagem na qualidade das sementes de pimenta Habanero Yellow. Foram utilizadas sementes extraidas de frutos em quatro epocas de colheita (E1 - 50, E2 - 60, E3 - 67 e E4 - 67 DAA e mantidos em repouso por 7 dias apos a colheita). As sementes extraidas dos frutos em diferentes epocas de colheita foram submetidas a quatro metodos de secagem: secagem artificial, aos 45 °C, ate 8% de teor de agua; secagem artificial, aos 35 °C, ate 20% de teor de agua, seguida de secagem aos 45 °C, ate 8% de teor de agua; secagem artificial, aos 35 °C, ate 8% de teor de agua; e secagem natural a sombra ate 8% de teor de agua). A qualidade fisiologica das sementes antes da secagem foi avaliada por meio dos testes de germinacao, emergencia e envelhecimento acelerado, alem da analise das isoenzimas esterase, superoxido dismutase, peroxidase, malato desidrogenase, alcool desidrogenase e da endo-β-mananase. Apos a secagem, a qualidade fisiologica das sementes foi avaliada por meio dos testes de germinacao, emergencia e deterioracao controlada. A qualidade fisiologica das sementes e maxima aos 67 DAA, quando os frutos estao completamente maduros. Maiores valores de germinacao e vigor sao observados em sementes secadas aos 35 oC.

Qualidade fisiológica e teor de lignina no tegumento de sementes de soja convencional e transgênica RR submetidas a diferentes épocas de colheita

Tem-se levantado a hipotese de que cultivares de soja RR possuem teores de lignina superiores aos convencionais, o que proporciona maior resistencia a danos mecânicos e maior impermeabilidade do tegumento das sementes. Objetivou-se avaliar a qualidade fisiologica e o teor de lignina no tegumento das sementes de soja convencional e RR colhidas em tres epocas, em Lavras-MG. Para tanto, as sementes colhidas nos estadios R7, R8 e apos 20 dias de retardamento da colheita (R8+20), foram submetidas aos testes para avaliacao da qualidade fisiologica e teor de lignina. As cultivares convencionais e RR avaliadas foram: BRS 133 vs BRS 245 RR, BRS 134 vs BRS 247 RR, Conquista vs Valiosa RR, Celeste vs Baliza RR e Jatai vs Silvânia RR. Foram realizados os testes de peso de mil sementes, germinacao, envelhecimento acelerado, condutividade eletrica, dano mecânico, indice de velocidade de emergencia, germinacao apos a imersao das sementes em agua e teor de lignina no tegumento de sementes. Com excecao do teor de lignina no tegumento de sementes para o contraste Jatai vs Silvânia RR, nao foram observadas diferencas entre os materiais RR e convencional, tendo, neste caso, a cv Silvânia RR apresentado resultados superiores aos da convencional. No entanto, houve diferenca de comportamento entre os cultivares quanto a tolerância ao retardamento da colheita. Observou-se reducao significativa na porcentagem de germinacao e vigor das sementes avaliadas com o retardamento da colheita.

Development of microsatellite markers for identifying Brazilian Coffea arabica varieties

Microsatellite markers, also known as SSRs (Simple Sequence Repeats), have proved to be excellent tools for identifying variety and determining genetic relationships. A set of 127 SSR markers was used to analyze genetic similarity in twenty five Coffea arabica varieties. These were composed of nineteen commercially important Brazilians and six interspecific hybrids of Coffea arabica, Coffea canephora and Coffealiberica. The set used comprised 52 newly developed SSR markers derived from microsatellite enriched libraries, 56 designed on the basis of coffee SSR sequences available from public databases, 6 already published, and 13 universal chloroplast microsatellite markers. Only 22 were polymorphic, these detecting 2-7 alleles per marker, an average of 2.5. Based on the banding patterns generated by polymorphic SSR loci, the set of twenty-five coffee varieties were clustered into two main groups, one composed of only Brazilian varieties, and the other of interspecific hybrids, with a few Brazilians. Color mutants could not be separated. Clustering was in accordance with material genealogy thereby revealing high similarity.

Armazenabilidade de sementes de cafeeiro colhidas em diferentes estádios de maturação e submetidas a diferentes métodos de secagem

The harvesting time and drying methods may influence the quality of coffee seeds during storage. This work was conducted with the objective of understand the effects of maturation stages and drying methods on the physiological quality and storability of coffee seeds. The experiments were performed at the Seed Analysis and Electrophoresis Laboratory of the Department of Agricultural of UFLA. The fruits of the cultivar Rubi were harvested, depulped and the mucilages removed by fermentation and the seeds washed and let on paper for removal of the water. The seeds were submitted to conventional drying (under shade) and drying in stationary drier at temperature of 35oC. As a control, seeds with no drying were analyzed. The evaluations were done soon after the drying treatments and after four and eight months of storage. The seeds were stored at 10oC in air-tight plastic packages. The germination test, radicle protrusion, seedling dry matter, emergence index speed, electric conductivity, electrophoresis analyses of heat-resistant proteins and quantification of endo-â-mannanase activity were the parameter evaluated. The design was completely randomized with 2 (maturation stages) x 3 (dryings) x 3 (storage time) factorial scheme with four replications. Seeds harvested in the cherry stage have greater storage potential than in the green-yellow stage. Reduced germination and vigor occur in the coffee seeds harvested in the green yellow stage, when submitted to fast drying. The presence or intensity heat-resistant protein bands is associated with seed drying. Greater activity of endo-s-mananase enzyme occurs in seeds harvested in the cherry stage than in the green yellow stage. Increase of the activity of endo-s-mananase enzyme occurs during storage.

Genetic purity certificate in seeds of hybrid maize using molecular markers

One of the main features that confer high quality to the seed is its genetic purity, in which one of the major causes of contamination is the self-pollination of the female parent. Up to date, there is no accurate and fast methods for detecting such contamination. Thus, this work was carried out to certify the genetic purity in seeds of hybrid maize using different biochemical and DNA-based markers. Two single-cross hybrids and their parental lines derived from the maize breeding program at UFLA were evaluated by isoenzymatic pattern of alcohol dehydrogenase (ADH), esterase (EST), acid phosphatase (ACP), glutamate-oxaloacetate transaminase (GOT), malate dehydrogenase (MDH), isocitrate dehydrogenase (IDH), phosphoglucomutase (PGM), 6-phosphoglucomate dehydrogenase (PGDH), catalase (CAT) and s-glucosidade (sGLU) and by microsatellites markers. The enzymatic systems that were able to distinguish the hybrids from their parental line were the catalase, the isocitrate dehydrogenase and the esterase. The esterase showed a Mendelian segregation pattern for UFLA 8/3 hybrid, that enables a safer genetic purity certificate. Microsatellites were able to differentiate the hybrid lines and the respective parental lines. Moreover, this technique was fast, precise and without environment effects. For microsatellites, the amplification pattern was identical when young leaves or seeds were used as DNA source. The possibility of using seeds as DNA source would accelerate and facilitate the role process of the genetic purity analysis.

Soybean cultivar characterization using morphological descriptors and protein and isoenzyme biochemical markers

The use of morphological descriptors and protein and isozymes biochemical markers have been recommended for soybean cultivar characterization. The aim of this study was to identify ten soybean cultivars using such descriptors and markers. The morphological descriptors evaluated in seedlings, plants and seeds were those recommended by the Cultivars Protection Act and UPOV and were efficient in cultivar separation. Specific markers for seven of the ten cultivars were obtained. Total protein separated the cultivars into three groups: 1) Conquista, BRIAC 21 and Garantia; 2) Lideranca, Confianca and Monarca; 3) Splendor, UFV 16, FT 2000 and Vencedora. Superoxide dismutase, diaforase, phosphoglucomutase, esterase, alcohol desidrogenase, isocitrado desidrogenase and peroxidase separated the cultivars into six groups: 1) Conquista and Confianca; 2) Splendor and FT 2000; 3) UFV 16 and Garantia; 4) BRIAC 21; 5) Lideranca and Monarca; 6) Vendedora. The use of biochemical markers with morphological descriptors was useful to soybean cultivar characterization.