Role of beneficial microbes with nitrogen and phosphorous levels on canola productivity / Papel de microbes benéficos em associação com níveis de nitrogênio e fósforo na produtividade de canola

A research was conducted to evaluate the impact of various nitrogen and phosphorus levels along with beneficial microbes to enhance canola productivity. The research was carried out at Agronomy Research Farm, The University of Agriculture Peshawar in winter 2016-2017. The experiment was conducted in randomized complete block factorial design. The study was comprised of three factors including nitrogen (60, 120 and 180 kg ha-¹), phosphorous (70, 100 and 130 kg ha-¹) and beneficial microbes (with and without BM). A control treatment with no N, P and BM was also kept for comparison. Application of beneficial microbes significantly increased pods plant, seed pod, seed filling duration, 1000 seed weight, biological yield and seed yield as compared to control plots. Nitrogen applied at the rate of 180 kg ha-¹ increased pods plant-¹, seed pod, seed filling duration, seed weight, biological yield and seed yield. Maximum pods plant-¹, seed pod, early seed filling, heavier seed weight, biological yield, seed yield, and harvest index were observed in plots treated with 130 kg.ha-¹ phosphorous. As comparison, the combine treated plots have more pods plant-¹, seeds pod-¹, seed filling duration, heaviest seeds, biological yield, seed yield and harvest index as compared to control plots. It is concluded that application of beneficial microbes with N and P at the rate of 180 kg ha-¹ and 130 kg ha-¹, respectively, increased yield and its attributes for canola.(AU)

Uma pesquisa foi realizada para avaliar o impacto de vários níveis de nitrogênio e fósforo, juntamente com micróbios benéficos, para aumentar a produtividade da canola. A pesquisa foi realizada no inverno de 2016-17 no Agronomy Research Farm, Universidade de Agricultura do Peshawar. O experimento foi conduzido por planejamento fatorial aleatorizado em blocos. O estudo focou-se em três fatores, incluindo o teor de nitrogênio, N, (60, 120 e 180 kg.ha-¹), o teor de fósforo, P, (70, 100 e 130 kg ha-¹) e a presença de micróbios benéficos (com BM e sem BM). Para fins de comparação, um tratamento controle sem N, P e BM também foi incluído no estudo. A aplicação de micróbios benéficos aumentou significativamente as vagens das plantas e de sementes, a duração do enchimento das sementes, o peso de 1000 sementes, o rendimento biológico e o rendimento de sementes em comparação com os resultados do controle. O nitrogênio aplicado na taxa de 180 kg ha-¹ aumentou as vagens por planta, vagem, duração do enchimento, peso da semente, rendimento biológico e rendimento de sementes. Vagens máximas por planta, vagem, enchimento precoce de sementes, peso maior de semente, rendimento biológico, rendimento de sementes e índice de colheita foram observados em parcelas tratadas com 130 kg.ha-¹ de fósforo. Em comparação aos blocos cultivados de controle, os blocos cultivados tratados combinados têm mais vagens por planta e sementes por vagem, maior duração do enchimento das sementes, maior número de sementes mais pesadas e maior rendimento biológico, rendimento de sementes e índice de colheita. Conclui-se que a aplicação de micróbios benéficos junto com N e P nas doses de 180 kg ha-¹ e 130 kg ha-¹, respectivamente, aumentou a produtividade e atributos de produtividade para a canola.(AU)

Role of beneficial microbes with nitrogen and phosphorous levels on canola productivity / Papel de microbes benéficos em associação com níveis de nitrogênio e fósforo na produtividade de canola

A research was conducted to evaluate the impact of various nitrogen and phosphorus levels along with beneficial microbes to enhance canola productivity. The research was carried out at Agronomy Research Farm, The University of Agriculture Peshawar in winter 2016-2017. The experiment was conducted in randomized complete block factorial design. The study was comprised of three factors including nitrogen (60, 120 and 180 kg ha-¹), phosphorous (70, 100 and 130 kg ha-¹) and beneficial microbes (with and without BM). A control treatment with no N, P and BM was also kept for comparison. Application of beneficial microbes significantly increased pods plant, seed pod, seed filling duration, 1000 seed weight, biological yield and seed yield as compared to control plots. Nitrogen applied at the rate of 180 kg ha-¹ increased pods plant-¹, seed pod, seed filling duration, seed weight, biological yield and seed yield. Maximum pods plant-¹, seed pod, early seed filling, heavier seed weight, biological yield, seed yield, and harvest index were observed in plots treated with 130 kg.ha-¹ phosphorous. As comparison, the combine treated plots have more pods plant-¹, seeds pod-¹, seed filling duration, heaviest seeds, biological yield, seed yield and harvest index as compared to control plots. It is concluded that application of beneficial microbes with N and P at the rate of 180 kg ha-¹ and 130 kg ha-¹, respectively, increased yield and its attributes for canola.

Uma pesquisa foi realizada para avaliar o impacto de vários níveis de nitrogênio e fósforo, juntamente com micróbios benéficos, para aumentar a produtividade da canola. A pesquisa foi realizada no inverno de 2016-17 no Agronomy Research Farm, Universidade de Agricultura do Peshawar. O experimento foi conduzido por planejamento fatorial aleatorizado em blocos. O estudo focou-se em três fatores, incluindo o teor de nitrogênio, N, (60, 120 e 180 kg.ha-¹), o teor de fósforo, P, (70, 100 e 130 kg ha-¹) e a presença de micróbios benéficos (com BM e sem BM). Para fins de comparação, um tratamento controle sem N, P e BM também foi incluído no estudo. A aplicação de micróbios benéficos aumentou significativamente as vagens das plantas e de sementes, a duração do enchimento das sementes, o peso de 1000 sementes, o rendimento biológico e o rendimento de sementes em comparação com os resultados do controle. O nitrogênio aplicado na taxa de 180 kg ha-¹ aumentou as vagens por planta, vagem, duração do enchimento, peso da semente, rendimento biológico e rendimento de sementes. Vagens máximas por planta, vagem, enchimento precoce de sementes, peso maior de semente, rendimento biológico, rendimento de sementes e índice de colheita foram observados em parcelas tratadas com 130 kg.ha-¹ de fósforo. Em comparação aos blocos cultivados de controle, os blocos cultivados tratados combinados têm mais vagens por planta e sementes por vagem, maior duração do enchimento das sementes, maior número de sementes mais pesadas e maior rendimento biológico, rendimento de sementes e índice de colheita. Conclui-se que a aplicação de micróbios benéficos junto com N e P nas doses de 180 kg ha-¹ e 130 kg ha-¹, respectivamente, aumentou a produtividade e atributos de produtividade para a canola.

Lead effects on Brassica napus photosynthetic organs.

In this study, effects of lead on ultracellular structure and pigment contents of Brassica napus were examined. Pb(II) was added in soluble form to soil prior to sowing. Pb contents were measured in plant organs at the ontogenetic stages of flowering (FL) and physiological maturity (PM). Pigment contents were evaluated through reflectance measurements. Pb content in organs was found to decrease in the order; roots>stems>leaves. Lead content in senescent leaves at FL stage was significantly higher than harvested leaves, strongly suggesting a detoxification mechanism. Leaves and stems harvested at the PM stage showed damage at subcellular level, namely chloroplast disorganization, cell wall damage and presence of osmiophilic bodies. Chlorophyll content increased in the presence of Pb at the FL stage, compared with control; at the PM stage, chlorophyll contents decreased with low Pb concentration but showed no significant differences with control at high Pb soil concentration. The results suggest an increase in antioxidants at low Pb concentration and cell damage at higher lead concentration.

IMI resistance associated to crop-weed hybridization in a natural Brassica rapa population: characterization and fate.

Wild turnip (Brassica rapa) is a common weed and a close relative to oilseed rape (Brassica napus). The Clearfield® production system is a highly adopted tool which provides an alternative solution for weed management, but its efficiency is threatened by gene transfer from crop to weed relatives. Crop-weed hybrids with herbicide resistance were found in the progeny of a B. rapa population gathered from a weedy stand on the borders of an oilseed rape (B. napus) imidazolinone (IMI)-resistant crop. Interspecific hybrids were confirmed by morphological traits in the greenhouse and experimental field, survival after imazethapyr applications, DNA content through flow cytometry, and pollen viability. The transference of herbicide resistance was demonstrated even in a particular situation of pollen competition between both an herbicide-resistant crop and a non-resistant crop. However, IMI resistance was not found in further generations collected at the same location. These results verify gene transmission from oilseed rape to B. rapa in the main crop area in Argentina where resistant and susceptible varieties are found and seed loss and crop volunteers are common. Hybridization, introgression, and herbicide selection would be associated with the loss of effectiveness of IMI technology.

Transgenic glyphosate-resistant oilseed rape (Brassica napus) as an invasive weed in Argentina: detection, characterization, and control alternatives.

The presence of glyphosate-resistant oilseed rape populations in Argentina was detected and characterized. The resistant plants were found as weeds in RR soybeans and other fields. The immunological and molecular analysis showed that the accessions presented the GT73 transgenic event. The origin of this event was uncertain, as the cultivation of transgenic oilseed rape cultivars is prohibited in Argentina. This finding might suggest that glyphosate resistance could come from unauthorized transgenic oilseed rape crops cultivated in the country or as seed contaminants in imported oilseed rape cultivars or other seed imports. Experimentation showed that there are alternative herbicides for controlling resistant Brassica napus populations in various situations and crops. AHAS-inhibiting herbicides (imazethapyr, chlorimuron and diclosulam), glufosinate, 2,4-D, fluroxypyr and saflufenacil proved to be very effective in controlling these plants. Herbicides evaluated in this research were employed by farmers in one of the fields invaded with this biotype and monitoring of this field showed no evidence of its presence in the following years.

Glyphosate-Resistant and Conventional Canola (Brassica napus L.) Responses to Glyphosate and Aminomethylphosphonic Acid (AMPA) Treatment.

Glyphosate-resistant (GR) canola contains two transgenes that impart resistance to the herbicide glyphosate: (1) the microbial glyphosate oxidase gene (gox) encoding the glyphosate oxidase enzyme (GOX) that metabolizes glyphosate to aminomethylphosphonic acid (AMPA) and (2) cp4 that encodes a GR form of the glyphosate target enzyme 5-enolpyruvylshikimic acid-3-phosphate synthase. The objectives of this research were to determine the phytotoxicity of AMPA to canola, the relative metabolism of glyphosate to AMPA in GR and conventional non-GR (NGR) canola, and AMPA pool sizes in glyphosate-treated GR canola. AMPA applied at 1.0 kg ha(-1) was not phytotoxic to GR or NGR. At this AMPA application rate, NGR canola accumulated a higher concentration of AMPA in its tissues than GR canola. At rates of 1 and 3.33 kg ae ha(-1) of glyphosate, GR canola growth was stimulated. This stimulatory effect is similar to that of much lower doses of glyphosate on NGR canola. Both shikimate and AMPA accumulated in tissues of these glyphosate-treated plants. In a separate experiment in which young GR and NGR canola plants were treated with non-phytotoxic levels of [(14)C]-glyphosate, very little glyphosate was metabolized in NGR plants, whereas most of the glyphosate was metabolized to AMPA in GR plants at 7 days after application. Untreated leaves of GR plants accumulated only metabolites (mostly AMPA) of glyphosate, indicating that GOX activity is very high in the youngest leaves. These data indicate that more glyphosate is transformed to AMPA rapidly in GR canola and that the accumulated AMPA is not toxic to the canola plant.

Effect of exogenous gibberellin on reserve accumulation during the seed filling stage of oilseed rape.

Exogenous gibberellins (GAs) are widely applied to increase crop yields, with knowledge about the physiological functioning and biochemistry mechanisms of these phytohormones improving; however, information remains limited about the effect of GAs on seed filling. In this study, the siliques (containing the seeds) of oilseed rape (Brassica napus L.) were treated with GA3 at 3 stages of seed filling. We confirmed that GA3 regulates the deposition of storage reserves in developing seeds. The percentage of crude fat in the seeds increased during the early stage, but remained stable during the middle and late stages. In comparison, the percentage of total protein decreased during the early and middle stages, but significantly increased during the late stage. In addition, Q-PCR was employed to analyze the expression level of related genes in response to GA3. It was found that the expression of WRI and ABI3 transcription factors corresponded to crude fat content and total protein content, respectively. The expression of storage reserve related genes DGAT, MCAT, SUC2, and GPT was consistent with crude fat content, whereas the expression of Napin corresponded to total protein content. The results of this study indicate that exogenous GA3 has a different effect on storage reserve deposition in seed during different stages of seed filling, and the effect might be achieved via changing the expression of related genes.

Assessment of allelopathic properties of Aloe ferox Mill. on turnip, beetroot and carrot.

Turnip (Brassica rapa var. rapa L.), beetroot (Beta vulgaris L.) and carrot (Daucus carota L.) are common vegetables in South Africa. The allelopathic potential of aqueous leaf and root extracts of Aloe ferox Mill.- a highly valued medicinal plant- was evaluated against seed germination and seedling growth of the three vegetables in Petri dish experiments. The extracts were tested at concentrations of 2, 4, 6, 8, and 10 mg/mL. Leaf extract concentrations above 4 mg/mL inhibited the germination of all the crops, while the root extract had no significant effect on germination irrespective of concentration. Interestingly, the lowest concentration of leaf extract stimulated root length elongation of beetroot by 31.71%. Other concentrations significantly inhibited both root and shoot growth of the vegetable crops except the turnip shoot. The most sensitive crop was carrot, with percentage inhibition ranging from 29.15 to 100% for root and shoot lengths. Lower percentage inhibition was observed for the root extract than the leaf extract against shoot growth of beetroot and carrot. The results from this study suggested the presence of allelochemicals mostly in the leaves of A. ferox that could inhibit the growth of the turnip, beetroot and carrot.

Assessment of allelopathic properties of Aloe ferox Mill. on turnip, beetroot and carrot

Turnip (Brassica rapa var. rapa L.), beetroot (Beta vulgaris L.) and carrot (Daucus carota L.) are common vegetables in South Africa. The allelopathic potential of aqueous leaf and root extracts of Aloe ferox Mill.- a highly valued medicinal plant- was evaluated against seed germination and seedling growth of the three vegetables in Petri dish experiments. The extracts were tested at concentrations of 2, 4, 6, 8, and 10 mg/mL. Leaf extract concentrations above 4 mg/mL inhibited the germination of all the crops, while the root extract had no significant effect on germination irrespective of concentration. Interestingly, the lowest concentration of leaf extract stimulated root length elongation of beetroot by 31.71%. Other concentrations significantly inhibited both root and shoot growth of the vegetable crops except the turnip shoot. The most sensitive crop was carrot, with percentage inhibition ranging from 29.15 to 100% for root and shoot lengths. Lower percentage inhibition was observed for the root extract than the leaf extract against shoot growth of beetroot and carrot. The results from this study suggested the presence of allelochemicals mostly in the leaves of A. ferox that could inhibit the growth of the turnip, beetroot and carrot.

Phytoremediation of 2,4-dichlorophenol by Brassica napus hairy root cultures.

We have obtained hairy root cultures of Brassica napus with high biomass and genetic stability which produce peroxidases, enzymes involved in biodegradation processes. In this work, these hairy root cultures were used to study the removal of 2,4-dichlorophenol (2,4-DCP), a common contaminant in industrial effluents that is highly toxic for human and aquatic life. The optimum conditions to obtain high efficiency in the removal process were established. Roots were able to remove 2,4-DCP from aqueous solutions containing 100-1000 mg/l, in the presence of H(2)O(2) concentrations ranging from 5 to 10 mM. After a short period of incubation (15 min), high removal efficiencies were achieved (91-94%) and maximal removal, of approx. 97-98%, was obtained with 1 h of reaction. High removal efficiencies (93-95%) were observed in a broad pH range (pH 3-9), reaching 98-99% in the range pH 4-8. Moreover, roots could be re-used, almost for six consecutive cycles, to remove 2,4-DCP. The oxidation catalysed by peroxidases would be the main mechanism involved in this process. The results suggest that these cultures could be useful tools for phytoremediation.