Genetic characterization of a novel Phomopsis sp., a putative biocontrol agent for Carthamus lanatus.

A large number of isolates of Phomopsis sp. have been collected from the weed Carthamus lanatus (saffron thistle) in Australia, and their potential as biological control agents for weeds of the Asteraceae has been demonstrated. An analysis of their genetic diversity and a multigene phylogenetic analysis were undertaken to ascertain whether these isolates were distinct from other species of Phomopsis that commonly attack crop species in Australia. Minimal variation was found between the Phomopsis spp. isolated from saffron thistle, except two isolates that appeared to share identity with Diaporthe helianthii and P. viticola. Analysis of the selected isolates from saffron thistle with the nucleotide sequence of the partial ITS and tefl-alpha regions demonstrated that the sequences were distinct from all other species of Phomopsis so far described from crops in Australia. These findings provide strong support for the recognition of these isolates as a separate species of Phomopsis. The implications of these findings are discussed in relation to biological control of saffron thistle.

Estimating leaf appearance rate and phyllochron in safflower (Carthamus tinctorius L)

Cártamo pode ser uma alternativa para o mercado de flores, podendo ser comercializada como flor fresca ou seca. A estimativa da taxa de aparecimento de folhas (LAR) e do filocrono (tempo necessário para o aparecimento de folhas sucessivas) é importante no cálculo do número de folhas emergidas (NL) na planta, o qual é uma excelente medida de tempo vegetal. O objetivo deste trabalho foi estimar a taxa de aparecimento de folhas e o filocrono em cártamo (Carthamus tinctorius L.). Foi realizado um experimento em Santa Maria, RS, em estufa plástica de 8 x 15m. A semeadura foi em 03 de outubro de 2003 e a emergência foi em 08 de outubro de 2003. O delineamento experimental foi o de blocos ao acaso com três repetições. O NL na haste principal foi medido durante o período de 24 de outubro a 15 de novembro de 2003. Foi calculado o número de graus dia diário acima de uma temperatura base (5°C) e a soma térmica acumulada (TT). Foi realizada uma análise de regressão linear entre NL e TT. O coeficiente angular da regressão linear é a LAR (folhas/ °C dia) e o filocrono (°C dia/folha) foi estimado pelo inverso do coeficiente angular da regressão linear. A LAR foi 0,0467 ± 0,0203 folhas/ °C dia e o filocrono foi 25,5 ± 14,6 °C dia/folha.

Ecotoxicological evaluation of diesel-contaminated soil before and after a bioremediation process.

Evaluation of contaminated sites is usually performed by chemical analysis of pollutants in soil. This is not enough either to evaluate the environmental risk of contaminated soil nor to evaluate the efficiency of soil cleanup techniques. Information on the bioavailability of complex mixtures of xenobiotics and degradation products cannot be totally provided by chemical analytical data, but results from bioassays can integrate the effects of pollutants in complex mixtures. In the preservation of human health and environment quality, it is important to assess the ecotoxicological effects of contaminated soils to obtain a better evaluation of the healthiness of this system. The monitoring of a diesel-contaminated soil and the evaluation of a bioremediation technique conducted on a microcosm scale were performed by a battery of ecotoxicological tests including phytotoxicity, Daphnia magna, and nematode assays. In this study we biostimulated the native microflora of soil contaminated with diesel by adding nutrients and crop residue (corn straw) as a bulking agent and as a source of microorganisms and nutrients; in addition, moisture was adjusted to enhance diesel removal. The bioremediation process efficiency was evaluated directly by an innovative, simple phytotoxicity test system and the diesel extracts by Daphnia magna and nematode assays. Contaminated soil samples were revealed to have toxic effects on seed germination, seedling growth, and Daphnia survival. After biostimulation, the diesel concentration was reduced by 50.6%, and the soil samples showed a significant reduction in phytotoxicity (9%-15%) and Daphnia assays (3-fold), confirming the effectiveness of the bioremediation process. Results from our microcosm study suggest that in addition to the evaluation of the bioremediation processes efficiency, toxicity testing is different with organisms representative of diverse phylogenic levels. The integration of analytical, toxicological and bioremediation data is necessary to properly assess the ecological risk of bioremediation processes.

[Biological effect of seed-coating in Carthamus tinctorins].

OBJECTIVE: To study the Biological effect of seed-coating in Carthamus tinctorins. METHOD: Two kinds of seedcoating chemicals SCF1 and SCF2 were used in this experiment, the seed YM-99 and 27981-99 were coated by three kinds of ratio of seedcoating chemicals to seed. It was investigated that the germination energy and germination percentage in the room and the emergence rate, seedling stage growing, pest in the field. RESULT: Seedoating can improve the emergence rate and seedling stage growing, it also can effectively control aphid, rust and virosis during the growing period in C. tinctorins. CONCLUSION: Seedcoating has significant biological effect in C. tinctorins.