1. Abordagem biológica de Amaranthus retroflexus L. (Amaranthaceae)

Ensaios biológicos foram realizados para determinação da toxidade de Amaranthus retroflexus L. (Amaranthaceae) conhecido popularmente como "redroot pigweed". Extratos desta espécie foram testados para avaliar sua bioatividade em Artemia salina e citoxidade em células bovinas de rim. Os valores de DL50 para Artemia salina foram medidos a 1700 ppm. As cé

Revista Brasileira de Farmacognosia. Publicado em: 2009-06

2. The Nitrogen Use Efficiency of C3 and C4 Plants: I. Leaf Nitrogen, Growth, and Biomass Partitioning in Chenopodium album (L.) and Amaranthus retroflexus (L.)

The effect of applied nitrogen (N) on the growth, leaf expansion rate, biomass partitioning and leaf N levels of Chenopodium album (C3) and Amaranthus retroflexus (C4) were investigated. At a given applied N level, C. album had 50% greater leaf N per unit area (Na) than A. retroflexus. Nitrate accumulated at lower Na in A. retroflexus than C. album. A. retro

3. Action of Phytochrome During Prechilling of Amaranthus retroflexus L. Seeds

Dark germination of Amaranthus retroflexus L. seeds at 35° increased after several days of prechilling at 20° or lower. Irradiation with far-red light for short periods during the early hours of a prechilling period at 10° inhibited subsequent dark germination at 35°. The inhibition was completely reversible with red light. Far-red irradiation in the lat

4. The Nitrogen Use Efficiency of C3 and C4 Plants: II. Leaf Nitrogen Effects on the Gas Exchange Characteristics of Chenopodium album (L.) and Amaranthus retroflexus (L.)

The effect of leaf nitrogen (N) on the photosynthetic capacity and the light and temperature response of photosynthesis was studied in the ecologically similar annuals Chenopodium album (C3) and Amaranthus retroflexus (C4). Photosynthesis was linearly dependent on leaf N per unit area (Na) in both species. A. retroflexus exhibited a greater dependence of pho

5. Rehydration of Phytochrome in Imbibing Seeds of Amaranthus retroflexus L

6. The Nitrogen Use Efficiency of C3 and C4 Plants 1: III. Leaf Nitrogen Effects on the Activity of Carboxylating Enzymes in Chenopodium album (L.) and Amaranthus retroflexus (L.)

The relationships between leaf nitrogen content per unit area (Na) and (a) the initial slope of the photosynthetic CO2 response curve, (b) activity and amount of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC), and (c) chlorophyll content were studied in the ecologically similar weeds Chenopodium album (C3

7. Resistência de Amaranthus retroflexus a herbicidas inibidores da enzima acetolactato sintase no Brasil

Quando em competição com a cultura do algodoeiro, Amaranthus retroflexus é capaz de promover grande perda de produtividade. Devido à limitada disponibilidade de herbicidas seletivos para controle em pós-emergência dessa espécie daninha, algumas moléculas têm sido usadas por safras seguidas, o que pode ter levado à seleção de biótipos resistentes

Planta daninha. Publicado em: 2014-06

8. Changes in Phytochrome Expressed by Germination of Amaranthus retroflexus L. Seeds

Effects of red (600 to 680 nanometers) and far red (700 to 760 nanometers) irradiances on Amaranthus retroflexus L. seeds indicate that synthesis of phytochrome in the red-absorbing form takes place in water-imbibed nongerminating seeds at 35 C. After 96 hours in darkness, conversion of about 0.10% phytochrome to the far red-absorbing form induces 50% germin

9. Chloroplast membrane alterations in triazine-resistant Amaranthus retroflexus biotypes

The effectiveness of diuron, atrazine, procyazine, and cyanazine were compared in controlling growth of redroot pigweed (Amaranthus retroflexus L.) in hydroponic culture. A very marked differential inhibition response was observed for atrazine between resistant and susceptible biotypes. Procyazine and cyanazine exhibited less dramatic differential responses,

10. Biochemical characterization of a trypanosomatid isolated from the plant Amaranthus retroflexus

A protozoan flagelate has recently been isolated from Amaranthus retroflexus. This plant grows near economically important crops in southeastern Spain, which are known to be parasitized by Phytomonas spp. The present study focuses on the characterization of the energy metabolism of this new isolate. These flagellates utilize glucose efficiently as their prim

Memórias do Instituto Oswaldo Cruz. Publicado em: 2000-10

11. Multiple-and Cross-Resistance of Amaranthus retroflexus to Acetolactate Synthase (ALS) and Photosystem II (PSII) Inhibiting Herbicides in Preemergence

RESUMO A resistência a herbicidas em espécies do gênero Amaranthus ocorre frequentemente no mundo e está se tornando um grande problema em regiões algodoeiras no Brasil. O objetivo deste trabalho foi verificar a resistência cruzada e múltipla de biótipos de caruru-gigante (A. retroflexus) aos herbicidas utilizados em pré-emergência na cultura do al

Planta daninha. Publicado em: 06/05/2019

12. N deposition affects allelopathic potential of Amaranthus retroflexus with different distribution regions

ABSTRACT This study aims to determine the allelopathic potential of Amaranthus retroflexus (Ar) with different climatic zones on seed germination and growth of A. tricolor (At) treated with a gradient N addition. Ar leaf extracts only displayed significantly allelopathic potential on the underground growth of Ar but not the aboveground growth of At. The alle

An. Acad. Bras. Ciênc.. Publicado em: 2017-06