Variability within Calonectria ovata and its anamorph Cylindrocladium ovatum from Brazil

Calonectria ovata is presently known only from the Amazonas province of Brazil, where it causes a severe leaf spot disease of various eucalypt species. Collections of Ca. ovata from two locations in the Amazon, namely Tucurui and Monte Dourado, revealed isolates from Tucurui to have much larger conidia than those from Monte Dourado. Twenty-four isolates from these sites were subsequently mated in all possible combinations, and also compared via isozyme analysis. Results from this study supported C. ovatum to be a homogeneous species. Although it was morphologically more variable than reported earlier, all isolates exhibited a biallelic heterothallic mating system, and were designated as either MAT 1-1 or MAT 1-2 based on their mating type. Furthermore, C. ovatum was found to be an important pathogen commonly associated with leaf spot and cutting rot symptoms of various eucalypt species grown in the Amazon.Articl

Isoenzyme analysis of Arthrobotrys, a nematode-trapping fungus

Extraction and isoenzyme analysis of four isolates of Arthrobotrys including A. musiformis, A. robusta and A. conoides were conducted. Among the 14 enzymes studied by starch gel electrophoresis, using morpholine-citrate as gel/electrode buffer, the following nine enzymes showed interpretable banding patterns: <!-- $MVD$:face("Symbol") --><FONT FACE="Symbol">a</font>-esterase, fumarase, hexokinase, isocitrate dehydrogenase, leucine aminopeptidase, malate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphoglucomutase and phosphoglucoisomerase. All isolates studied displayed typical isoenzyme phenotypes for each species. Two isolates of A. conoides differed in their <!-- $MVD$:face("Symbol") --><FONT FACE="Symbol">a</font>-isoesterase banding patterns, but no differences were observed for the other enzymes. The assay was satisfactory for enzyme extraction and resolution of Arthrobotrys and could be used in future taxonomic and genetic studies of this organis

Isoflavone and protein content in soybeans grains submitted to flooding at different stages of development Teor de isoflavonas e proteínas nos grãos de soja submetida ao alagamento em diferentes estádios de desenvolvimento

The stress imposed on plants by soil flooding constitutes a major barrier to growth and productivity. The identification of soybean varieties that produce higher levels of isoflavones, is necessary as soybeans have been used as human food to reduce risks of chronic diseases. Thus, this study was conducted with the objective of quantifying proteins and isoflavones in soybean cultivars subjected to flooding at various stages of development. The cultivars 'BRS267', 'BRS257' and 'BRS213' were subjected to 15 days of flooding, starting at the stages V6 and V8 and 11 days under stress starting at the stage R4. The proteins in the grain were extracted and quantified and analyzed by SDS-PAGE electrophoresis. Isoflavones were extracted, separated and quantified on HPLC. The electrophoretic analysis of the three cultivars under study revealed the same pattern of banding relative to the total protein regardless of the treatment. However, it was noted that flooding led to an increase in the total contents of isoflavones in the BRS 267 plants flooded in stage R4, remaining constant in other cultivars.<br>O estresse imposto às plantas pelo alagamento do solo constitui uma barreira para o crescimento e produtividade destas. A identificação de cultivares de soja que possam produzir maior teor de isoflavonas torna-se necessária à medida que a soja vem sendo utilizada na alimentação humana e para redução dos riscos de doenças crônicas. Dessa forma, o presente estudo foi realizado com o objetivo de quantificar isoflavonas e proteínas em cultivares de soja submetidas ao alagamento em diferentes estádios de desenvolvimento. As cultivares 'BRS 267', 'BRS 257' e 'BRS 213' foram submetidas a 15 dias de alagamento, nos estádios V6 e V8 e 11 dias sob estresse, no estádio R4. As proteínas no grão foram extraídas e quantificadas e analisadas as eletroforeses em SDS-PAGE. Os isoflavonóides foram extraídos, separados e quantificados por HPLC. A análise por eletroforese das três cultivares revelou o mesmo padrão de bandas relativas às proteínas totais, independente do tratamento utilizado. O alagamento promoveu aumento no teor total de isoflavonas nas plantas alagadas no estádio R4 da cultivar 'BRS 267', permanecendo constante nas demais cultivares