RESUMO

A língua-de-vaca é uma planta daninha perene, que infesta principalmente pastagens, lavouras anuais e perenes na região Sul do Brasil. Por ser uma planta perene, o controle se torna mais difícil devido ao rebrote. O trabalho teve como objetivo acompanhar a fenologia e avaliar as características de crescimento e desenvolvimento de plantas de língua-de-vaca em ambiente não competitivo. O experimento foi conduzido em casa de vegetação, após as sementes terem germinado em câmara BOD, as plântulas foram transplantadas para vasos preenchidos com Cambissolo Háplico. Foram realizadas análises destrutivas aos 0, 33, 94, 124, 156, 186 e 215 dias após o transplantio (DAT). As plantas foram coletadas separando a parte aérea do sistema radicular e da inflorescência, cada parte da planta foi levada à estufa de secagem por circulação forçada de ar para posterior determinação da massa seca. Observou-se que as plantas de língua-de-vaca apresentam crescimento inicial bastante lento. A distribuição da massa seca total foi de 56,8% do total acumulado no sistema radicular, seguido pela inflorescência (31,6%) e parte aérea (11,6%). O número médio de sementes produzidas foi de 3.406 (± 389) por plantas.

Broad-leaved dock is a perennial weed, which infests mainly pastures, annual crops and perennials in the Southern of Brazil. Because it is a perennial plant, control becomes more difficult due to regrowth. The objective of this study was to evaluate the growth and development characteristics of cow-tongue plants in a non-competitive environment. The objective of this work was to monitor phenology and to evaluate the growth and development characteristics of broad-leaved dock plants in the non-competitive environment. The experiment was conducted in a greenhouse, after the seeds germinated in the BOD chamber, the seedlings were transplanted to pots filled with Cambisol Haplic. Destructive analyzes were performed at 0, 33, 94, 124, 156, 186 and 215 days after transplanting (DAT). The plants were collected separating the aerial part of the root system and the inflorescence, each part of the plant was taken to the drying oven by forced circulation of air for later determination of the dry mass. It was observed that the broad-leaved dock plants present initial growth rather slow. The total dry mass distribution was 56.8% of the total accumulated in the root system, followed by inflorescence (31.6%) and shoot (11.6%). The average number of seeds produced was 3,406 (± 389) per plant.ien

Assuntos

RESUMO

A língua-de-vaca é uma planta daninha perene, que infesta principalmente pastagens, lavouras anuais e perenes na região Sul do Brasil. Por ser uma planta perene, o controle se torna mais difícil devido ao rebrote. O trabalho teve como objetivo acompanhar a fenologia e avaliar as características de crescimento e desenvolvimento de plantas de língua-de-vaca em ambiente não competitivo. O experimento foi conduzido em casa de vegetação, após as sementes terem germinado em câmara BOD, as plântulas foram transplantadas para vasos preenchidos com Cambissolo Háplico. Foram realizadas análises destrutivas aos 0, 33, 94, 124, 156, 186 e 215 dias após o transplantio (DAT). As plantas foram coletadas separando a parte aérea do sistema radicular e da inflorescência, cada parte da planta foi levada à estufa de secagem por circulação forçada de ar para posterior determinação da massa seca. Observou-se que as plantas de língua-de-vaca apresentam crescimento inicial bastante lento. A distribuição da massa seca total foi de 56,8% do total acumulado no sistema radicular, seguido pela inflorescência (31,6%) e parte aérea (11,6%). O número médio de sementes produzidas foi de 3.406 (± 389) por plantas.(AU)

Broad-leaved dock is a perennial weed, which infests mainly pastures, annual crops and perennials in the Southern of Brazil. Because it is a perennial plant, control becomes more difficult due to regrowth. The objective of this study was to evaluate the growth and development characteristics of cow-tongue plants in a non-competitive environment. The objective of this work was to monitor phenology and to evaluate the growth and development characteristics of broad-leaved dock plants in the non-competitive environment. The experiment was conducted in a greenhouse, after the seeds germinated in the BOD chamber, the seedlings were transplanted to pots filled with Cambisol Haplic. Destructive analyzes were performed at 0, 33, 94, 124, 156, 186 and 215 days after transplanting (DAT). The plants were collected separating the aerial part of the root system and the inflorescence, each part of the plant was taken to the drying oven by forced circulation of air for later determination of the dry mass. It was observed that the broad-leaved dock plants present initial growth rather slow. The total dry mass distribution was 56.8% of the total accumulated in the root system, followed by inflorescence (31.6%) and shoot (11.6%). The average number of seeds produced was 3,406 (± 389) per plant.(AU)ien

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RESUMO

Abstract Aspergillus sp., Fusarium sp., and Ramularia sp. were endophytic fungi isolated from Rumex gmelini Turcz (RGT), all of these three strains could produce some similar bioactive secondary metabolites of their host. However the ability to produce active components degraded significantly after cultured these fungi alone for a long time, and were difficult to recover. In order to obtain more bioactive secondary metabolites, the co-culture of tissue culture seedlings of RGT and its endophytic fungi were established respectively, and RGT seedling was selected as producer. Among these fungi, Aspergillus sp. showed the most significant enhancement on bioactive components accumulation in RGT seedlings. When inoculated Aspergillus sp. spores into media of RGT seedlings that had taken root for 20 d, and made spore concentration in co-culture medium was 1 × 104 mL-1, after co-cultured for 12 d, the yield of chrysophaein, resveratrol, chrysophanol, emodin and physcion were 3.52-, 3.70-, 3.60-, 4.25-, 3.85-fold of the control group. The extreme value of musizin yield was 0.289 mg, which was not detected in the control groups. The results indicated that co-culture with endophytic fungi could significantly enhance bioactive secondary metabolites production of RGT seedlings.

Assuntos

RESUMO

Aspergillus sp., Fusarium sp., and Ramularia sp. were endophytic fungi isolated from Rumex gmelini Turcz (RGT), all of these three strains could produce some similar bioactive secondary metabolites of their host. However the ability to produce active components degraded significantly after cultured these fungi alone for a long time, and were difficult to recover. In order to obtain more bioactive secondary metabolites, the co-culture of tissue culture seedlings of RGT and its endophytic fungi were established respectively, and RGT seedling was selected as producer. Among these fungi, Aspergillus sp. showed the most significant enhancement on bioactive components accumulation in RGT seedlings. When inoculated Aspergillus sp. spores into media of RGT seedlings that had taken root for 20d, and made spore concentration in co-culture medium was 1×104mL-1, after co-cultured for 12d, the yield of chrysophaein, resveratrol, chrysophanol, emodin and physcion were 3.52-, 3.70-, 3.60-, 4.25-, 3.85-fold of the control group. The extreme value of musizin yield was 0.289mg, which was not detected in the control groups. The results indicated that co-culture with endophytic fungi could significantly enhance bioactive secondary metabolites production of RGT seedlings.

Assuntos

RESUMO

Fire affects grassland composition by selectively influencing recruitment. Some exotic species can increase their abundance as a consequence of fire-stimulated seed germination, but response may depend on seed age. Rumex acetosella L. (Polygonaceae, sheep's sorrel) is a cosmopolitan herb that has invaded NW Patagonia's grasslands. This species forms persistent soil seed banks and increases after disturbances, particularly fire. We studied how fire and seed longevity influence R. acetosella germination. In 2008, we conducted laboratory experiments where we exposed different-aged seeds (up to 19 years old) to heat, smoke, charcoal, ash and control treatments. Total percentage germination and mean germination time depended on both seed age and fire treatment. Germination of younger seeds decreased with increasing temperature. There was no general pattern in germination responses of different-aged seeds to smoke, charcoal and ash. While smoke improved the germination of fresh seeds, charcoal decreased germination. Germination of untreated seeds was negatively correlated with seed age, and mean germination time increased with seed age. In most treatments, fresh seeds had lower germination than 1-5-year-old seeds, indicating an after-ripening requirement. Smoke stimulates R. acetosella germination, causing successful recruitment during post-fire conditions. Fresh seeds are particularly responsive to fire factors, possibly because they have not experienced physical degradation and are more receptive to environmental stimuli. Knowing the colonisation potential from the soil seed bank of this species during post-fire conditions will allow us to predict their impact on native communities.

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