Eliane Augustin

Atividade de peroxidase e polifenoloxidase na resistência do feijão à antracnose

The objective of this work was to evaluate the influence of peroxidase and polyphenol oxidase enzymes in anthracnose resistance of four bean cultivars. Seedlings were sprinkled with salicylic acid and delta race of Colletotrichum lindemuthianum (inducer fungus) and after three days they were inoculated with 33/95 virulent pathotype of C. lindemuthianum. Enzyme activity and phenol levels were evaluated three days after inducer fungus application and five days after inoculation with virulent pathotype. Plants treated with salicylic acid and inducer fungus presented higher activity increases of both enzymes, in all cultivars. Higher impulses in enzymatic activity were observed in cultivars with higher disease resistance. One isoperoxidase appeared in treatments with inducer fungus, salicylic acid, after inoculation with virulent pathotype, and in control plants, in AB 136, Rio Tibagi and Macanudo cultivars. Positive correlation was observed among peroxidase and polyphenol oxidase activity, phenolic compound levels and anthracnose resistance.

Caracterização de cultivares de pessegueiro e de nectarineira por marcadores moleculares

In species with a narrow genetic basis, such as peach and nectarine (Prunus persica (L.) Batsch), the utilization of molecular markers in cultivar characterization is very important, besides the potential of use for protection. Gel electrophoresis and RAPD techniques were used to characterize peach cultivars Granada, Esmeralda, Jade, Eldorado, Riograndense, Capdeboscq, Aldrighi, Precocinho, Diamante, Turmalina, Maciel, BR-1, Pepita, Coral, Chinoca, Marfim, Chiripa, Della Nona and Planalto and nectarine cultivars Dulce and Anita. Isoenzymes of 6-phosphogluconate dehydrogenase and acid phosphatase in pollen, peroxidase, phosphoglucoisomerase, aspartate transaminase and isocitrate dehydrogenase in leaves, malate dehydrogenase, leucine aminopeptidase and phosphoglucomutase in pollen and leaves were analyzed. Fifty primers were tested and eleven were used to analyze RAPD markers in leaf extracts. Similarity and cluster analysis were conducted using Jaccard coefficient and the unweighted pair group method with arithmetic average. Despite the differences detected in malate dehydrogenase in peach and nectarine pollen and leaves, the low polymorphism presented by the other systems did not allow the characterization of all cultivars through gel electrophoresis. RAPD markers, associated or not to isoenzyme analysis, were efficient to characterize peach and nectarine cultivars.

Meiosis of anther culture regenerants in asparagus (Asparagus officinalis L.)

Foi analisada a meiose em celulas mae de polen de plantas de aspargo (Asparagus officinalis L.) de uma populacao composta exclusivamente de plantas masculinas, obtidas atraves do processo de cultura de anteras do hibrido G27 X 22-8. Foi observado que, durante o processo de cultura de anteras, via calogenese, as celulas mae de polen dos regenerantes apresentaram grande instabilidade genomica, evidenciada por irregularidades nas fases de diacinese, assim como de metafase, anafase, telofase da primeira e segunda divisao meiotica. Alem disto, o processo originou anormalidades cromossomicas estruturais em adicao as aneuploidias e poliploidias.

BRS Eliza: cultivar de batata para mesa, com película lisa e resistência à pinta-preta e à requeima

BRS Eliza is a tablestock potato cultivar released in 2001, by Embrapa Clima Temperado, Pelotas, Brazil. It is adequate for puree and salad. Maturity is medium early. Tubers are oval shaped, yellow and smooth skin, low sensitivity to greening, yellow clear flesh and shallow eyes. BRS Eliza did not show physiological defects on the tubers. Has a good field resistance to late (Phytophthora infestans) and early blight (Alternaria solani), and medium resistance to main viroses. BRS Eliza is susceptible to black leg (Erwinia carotovora). It produces a high percentage of commercial tubers. Must be marketed immediately after harvesting. It requires accurate seed management in storage.

Caracterização de variedades de batata doce (Ipomoea batatas L.) através de descritores morfológicos e isoenzimáticos

Despite the variability observed in sweet potato germplasm found in the Rio Grande do Sul State, many populations can not be morphologically characterized without the use of additional methods, such as isoenzyme analysis. The aim of this work was to evaluate the morphological and isoenzymatic characteristics of ten accesses of the genetic resources program of Embrapa Clima Temperado. Four morphological descriptors were used, which allowed to distinguish six varieties. Polyacrylamyde electrophoresis was used to analyze peroxidase, aspartate transaminase and esterase isoenzymes. Maximum similarity (1.00), estimated through Jaccard coefficient, was observed only in comparisons between Americana and Morada INTA. Varieties were classified into two groups and four subgroups, using UPGMA (unweighted pair-group method with arithmetic averages). All accesses could be differentiated. The results obtained indicated that isoenzyme analysis, associated to morphological evaluations, can be succesfully used to characterize sweet potato germplasm available in the Rio Grande do Sul.

Efeitos de meios de cultura na formação de calos a partir de anteras de aspargo (Asparagus officinalis L.)

Anther culture is an auxiliary technique to obtain new genotypes. In this work, anthers with pollen grains in the uninucleated stage of hybrids 56x22-8 and 47x22-8 were cultured in MS medium, semi-solid and liquid, with different concentrations of growth regulators: medium A - 0,5 mg/l BAP + 0,1 mg/l NAA + 0,5 mg/1 2,4-D + 20 g/l sucrose + 20 g/l glucose; medium B - 0,5 mg/1 2,4-D + 30 g/l sucrose; medium C - 3,0 mg/l NAA + 0,5 mg/l Kin + 30 g/l sucrose and medium D - 2,0 mg/l NAA + 0,5 mg/l Kin + 30 g/l sucrose. Callus formation varied with the genotype and the medium. Liquid media showed more efficiency in callus development than the semi-solids. For the hybrids 56x22-8 the best media were the liquid A2 with 80,5% of callus induction and among the semi-solids the D1, with 41,6%. For the hybrid 47x22-8 were liquid D2 with 68,1% and semi solid D1 with 15,2%. No significant differences were observed among the liquid media nor among the semi-solidones.