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Littérature scientifique sur le sujet « Wheat Growth »

Auteur : Grafiati

Publié le 4 juin 2021

Mis à jour le 31 janvier 2023

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Articles de revues sur le sujet "Wheat Growth"

Egamberdieva, D. « Growth response of wheat cultivars to bacterial inoculation in calcareous soil ». Plant, Soil and Environment 56, No. 12 (16 décembre 2010) : 570–73. http://dx.doi.org/10.17221/75/2010-pse.

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In this study the plant growth-promoting bacteria were analysed for their growth-stimulating effects on two wheat cultivars. The investigations were carried out in pot experiments using calcareous soil. The results showed that bacterial strains Pseudomonas spp. NUU1 and P. fluorescens NUU2 were able to colonize the rhizosphere of both wheat cultivars. Their plant growth-stimulating abilities were affected by wheat cultivars. The bacterial strains Pseudomonas sp. NUU1 and P. fluorescens NUU2 significantly stimulated the shoot and root length and dry weight of wheat cv. Turon, whereas cv. Residence was less affected by bacterial inoculation. The results of our study suggest that inoculation of wheat with Pseudomonas strains can improve plant growth in calcareous soil and it depends upon wheat cultivars. Prior to a selection of good bacterial inoculants, it is recommended to select cultivars that benefit from association with these bacteria.

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Khushnudovna, Khojaniyazova Barno. « ТHE EFFECT OF DIFFERENT ENVIRONMENTAL SALT LEVELS ON AUTUMN WHEAT GROWTH ». European International Journal of Multidisciplinary Research and Management Studies 02, n^o 04 (1 avril 2022) : 29–32. http://dx.doi.org/10.55640/eijmrms-02-04-07.

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Soil salinity i.e. the presence of a solution of salts in the soil solution above the alternative level for plants, leads to a decrease in productivity, which has a negative impact on the growth and development of wheat plants. Complex environmental conditions lead to a decrease in product quality, which is important for the economy, while reducing the yield of wheat. Improving the salinity resistance of wheat remains one of the most pressing issues today. The most effective environmentally friendly way to increase the resistance of plants to salinity is to create varieties that are resistant to these extreme conditions and to accelerate their introduction into production.

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Sakri, Faisal Abdulkadir, Noori Hassan Ghafor et Hoshiar Abdula Aziz. « Effect of Some Plant Growth Regulators on Growth and Yield Component of Wheat – Plants CV. Bakrajo ». Journal of Zankoy Sulaimani - Part A 5, n^o 2 (25 avril 2002) : 43–50. http://dx.doi.org/10.17656/jzs.10100.

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Priadkina, G. O., O. O. Stasik, A. M. Poliovyi, O. E. Yarmolska et K. Kuzmova. « Radiation use efficiency of winter wheat canopy during pre-anthesis growth ». Fiziologia rastenij i genetika 52, n^o 3 (juin 2020) : 208–23. http://dx.doi.org/10.15407/frg2020.03.208.

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JA, Domínguez, J. Kumhálová et P. Novák. « Winter oilseed rape and winter wheat growth prediction using remote sensing methods ». Plant, Soil and Environment 61, No. 9 (6 juin 2016) : 410–16. http://dx.doi.org/10.17221/412/2015-pse.

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Salantur, A., A. Ozturk et S. Akten. « Growth and yield response of spring wheat (Triticum aestivum L.) to inoculation with rhizobacteria ». Plant, Soil and Environment 52, No. 3 (15 novembre 2011) : 111–18. http://dx.doi.org/10.17221/3354-pse.

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The growth and yield response of spring wheat to inoculation with foreign and local rhizobacteria of Erzurum (Turkey) origin was studied. At the first stage of the research, a greenhouse experiment was carried out with wheat cv. Kirik using 75 local bacterial strains isolated from the soil with 6 foreign bacteria, and a control. According to results of the greenhouse experiment 9 local strains were identified. At the second stage, the response of wheat cv. Kirik to 20 treatments (9 local strains, 6 foreign bacteria, 4 levels of N, and a control) was investigated in Erzurum field conditions. Seventeen strains had significant positive effects on tiller number per plant, 47 strains on plant height, one strain on dry matter yield, and 28 strains on plant protein content in the greenhouse experiment. Inoculation with certain rhizobacteria clearly benefited growth and increased the grain and N-yield of field grown wheat. The effects of local strains were observed to be in general superior to those of foreign strains. Inoculation with the local Strain No. 19, 73, and 82 increased total biomass by 18.7, 18.1, and 19.9%; grain yield by 18.6, 17.7, and 18.0%; total N-yield by 27.5, 24.3 and 26.0%, respectively, as compared to control. In conclusion, Strain No. 19, 73, and 82 can be a suitable biofertilizer for spring wheat cultivation in areas with similar conditions as in Erzurum. Inoculation with these strains may lead both to increases in wheat yield and savings of nitrogen fertilizer.

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Espindula, M. C., V. S. Rocha, J. A. S. Grossi, M. A. Souza, L. T. Souza et L. F. Favarato. « Use of growth retardants in wheat ». Planta Daninha 27, n^o 2 (juin 2009) : 379–87. http://dx.doi.org/10.1590/s0100-83582009000200022.

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In general, lodging has been controlled by restricting nitrogen fertilizer application and/or using short cultivars. Growth retardants can also be used to solve this problem.The objective of this study was to evaluate the effect of rates and application times of three growth retardants on Pioneiro wheat cultivar. The trial was carried out in Viçosa-MG, from May to September 2005, in a factorial and hierarchical scheme, in a randomized block design with four replications and a control treatment. The treatments consisted of 500, 1,000 and 1,500 g ha-1 of chlormequat; 62.5, 125 and 187.5 g ha-1 of trinexapac-ethyl and 40, 80 and 120 g ha-1 of paclobutrazol applied at growth stages 6 or 8, growth stage used on the scale of Feeks and Large, and a control treatment without growth retardant application. Only trinexapac-ethyl and chlormequat were efficient in reducing plant height; the effect of chlormequat and paclobutrazol on plant height was independent of the application time, but the trinexapac-ethyl at growth stage 8 produced shorter plant height than at stage 6. Increasing growth retardant rates produced shorter plant heights; chlormequat and paclobutrazol did not affect grain yield. However, the highest trinexapac-ethyl rates reduced wheat yield.

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Delone, N. L., Yu A. Berkovich, S. O. Smolyanina, N. V. Zimina, N. V. Davydova, A. A. Solovyev et L. S. Bolshakova. « Vibration-induced stimulation of wheat growth ». Doklady Biological Sciences 434, n^o 1 (octobre 2010) : 332–34. http://dx.doi.org/10.1134/s001249661005011x.

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Agrawal, R. P., et B. S. Jhorar. « Soil Aggregates and Growth of Wheat ». Journal of Agronomy and Crop Science 158, n^o 3 (avril 1987) : 160–62. http://dx.doi.org/10.1111/j.1439-037x.1987.tb00257.x.

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PRITCHARD, J., A. D. TOMOS et R. G. WYN JONES. « Control of Wheat Root Elongation Growth ». Journal of Experimental Botany 38, n^o 6 (1987) : 948–59. http://dx.doi.org/10.1093/jxb/38.6.948.

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Thèses sur le sujet "Wheat Growth"

Zubaidi, Akhmad. « Growth and yield of durum and bread wheat ». Title page, contents and summary only, 1996. http://web4.library.adelaide.edu.au/theses/09A/09az93.pdf.

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Bibliography: leaves 148-160. A series of experiments was conducted to examine the growth and nutrient uptake of durum and bread wheat at a number of sites in South Australia. The experiments examined response to water stress, the pattern of root and shoot growth, soil water extraction and nutrient uptake among a range of adapted bread wheat and durum wheat cultivars.

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Ottman, Michael. « Predicting Wheat Growth Using the CSM-Cropsim-CERES - Wheat Crop Model ». College of Agriculture, University of Arizona (Tucson, AZ), 2008. http://hdl.handle.net/10150/203650.

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CSM-Cropsim-CERES -Wheat is a crop growth model that predicts crop development stages, among other things, using genetic coefficients for vernalization and photoperiod. We used this model to predict flowering date for 12 durum varieties seeded in trials at Maricopa and Yuma from 1998 to 2006. The difference between simulated and measured flowering date averaged 4 days without genetic coefficients and improved to 3.5 days if genetic coefficients for flowering and vernalization were included for each variety.

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Barczys, Cathleen. « THE EFFECT OF AUDIBLE SOUND FREQUENCY ON THE GROWTH RATE OF YOUNG WHEAT PLANTS ». Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275379.

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Hopkins, Laura. « The effects of elevated ultraviolet-B radiation on the growth and developmentof the primary leaf of wheat (Triticum aestivum L. cv Maris Huntsman) ». Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/13563.

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Seedlings of Triticum aestivum L. cv. Maris Huntsman were grown for 7 days in a controlled environment chamber (16 hour photoperiod: PAR - photosynthetically active radiation), in the presence and absence of ultraviolet-B (UV-B: 280-320nm) radiation (+30% increase on ambient). UV-B resulted in a 17% reduction in leaf length due to changes in both the rate and duration of cell division and elongation. Measurements of the spatial distribution of cell division and elongation within the primary leaf were used to determine the temporal distribution of cells (i.e. cell age). The cell age gradient allows for the comparison of direct, and indirect UV-B responses, which result from the altered growth. Direct effects of UV-B included a reduction in chloroplast and mitochondrial transverse area, and an increase in chloroplast number, which suggests that UV-B affects organelle division. The developmental changes in protein content and amino acid free pools were increased as a direct result of UV-B treatment. In contrast, increases in chlorophyll content were due to an indirect effect of UV-B via altered growth. UV-B had no effect on the developmental changes in photosynthetic capacity and efficiency, and carbohydrate status of the primary leaf The primary leaf of wheat has provided a model system in which to examine the effects of UV-B on leaf development. This study highlights the need to consider cell age when determining the response of plants to UV-B.

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Bond, Mark Anthony. « The effects of enhanced UV-B and CO2 on the growth and development of Triticum aestivum ». Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/13561.

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Seedlings of Triticum aestivum L. (cv Maris Huntsman) were propagated in a controlled environment chamber to 240hr (post-imbibition) under ambient, enhanced UV-B (200Wm-2), CO2 (550ppm and 700ppm) and combined UV-B/CO2 treatments. The grass leaf developmental model was used to determine changes in the cell-age gradient along the leaf length, under these treatments. By full leaf expansion, enriched CO2 had significantly increased leaf height, whilst this was decreased under enhanced UV-B, and decreased further under the combined UV-B/CO2 treatment. Analysis of the zones of cell division and cell elongation at the leaf base established that enriched CO2 increased mitotic activity and more so, cell elongation rates, whilst enhanced UV-B predominantly extended the duration of the cell division cycle. Under the combined UV-B/CO2 (550ppm) treatment it is proposed that cell division and cell elongation are greatly reduced at leaf emergence, but CO2-induced increases of cell division rates occur over time, prior to early cessation of leaf growth. The reduced leaf cell supply under enhanced UV-B+/-CO2 was accompanied by reductions in chlorophyll and protein synthesis at the leaf base, more so on a cell-age basis. Enhanced UV-B+/-CO2 did not alter the leaf Rubisco content. However, coleoptile Rubisco content was significantly reduced under enhanced UV-B, but this effect was ameliorated in combination with CO2. Large increases in UV-B-absorbing compounds accumulated along the leaf under enhanced UV-B+CO2 (550ppm), although this was attributed primarily to altered cell-age gradients rather than to UV-B induction per se. Analysis by Differential Display Reverse Transcription-PCR of the cell division zone has led to the isolation of 19 up-regulated and 11 down-regulated putative UV-B responsive transcripts. It is believed that the use of DDRT-PCR will further elucidate specific plant responses under these treatments.

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Zahedi, Morteza. « Physiological aspects of the responses of grain filling to high temperature in wheat ». Title page, abstract and contents only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phz19.pdf.

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"June 2001." Includes bibliographical references (leaves 217-248). The effects of a sustained period of moderately high temperature on physiological and biochemical aspects of grain development were investigated in wheat cultivars grown under controlled environment conditions. The effect of variation in plant nutrition on the responses of cultivars to high temperature was also studied.

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Caley, Clare Yvonne. « Termination of grain growth in cereals ». Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/27746.

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Miranda, L. N. de. « Aluminium-phosphate interactions in relation to wheat growth ». Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355697.

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Arif, Hamayun. « Water relations of salt stressed wheat ». Thesis, Bangor University, 1990. https://research.bangor.ac.uk/portal/en/theses/water-relations-of-salt-stressed-wheat(b523794e-42f4-4165-bb35-11f07b7bbf28).html.

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The present study was conducted to investigate the water relations of individual plant cells and the biophysical parameters controlling plant growth in the context of salt stress. Growth and water relations were studied in growing as well as in mature zones of the first emerged leaf of wheat seedlings (cv. Flanders, a British variety) in the context of NaCl stress. Various levels of NaCl (0,25,50,75,100,125 and 150 mol m) -3 were used to salinize the media. I In the case of leaf elongation rate a two phase response was found i. e. an immediate decrease and then, a recovery in the elongation rate. Leaf elongation rate decreased within 1-2 minutes of the onset of stress and, later, a recovery started 1-2 h after the salt addition. The time taken for the recovery was proportional to the levels of external salinity. After 24 h the elongation rate was almost fully recovered for all the NaCl concentrations. A similar response was observed when equi-osmolar concentrations (with NaCl) of mannitol were added to the media. In control plants turgor pressure of the expanding cells was about 0.45 MPa while tissue osmotic pressure was equal to 1.1 MPa showing that the cell had a low water potential (-0.6 MPa). The transpiration tension was equivalent to 0.1 MPa. Turgor pressure in th e growing cells did not change after the salt addition (0- 150 mol m-3 NaCl), however, the tissue osmotic pressure continuously increased with time. Turgor pressure dropped when more -3 than 150 mol m NaCl were applied to the media i. e. 200 and 250 mol m. -3 This is presented as evidence that growing leaf cells - maintained their turgor pressure In response. to . the salt stress by taking up osmotically -active solutes present in the cell wall. The salt stress had not any effect on Instron tensiometric measurements of elastic and plastic extension of the cell wall. A different turgor pressure response was found in the mature cells. Turgor pressure was about 1.0 MPa, almost twice that in the growing cells, while tissue osmotic pressure was similar to that found in the growing cells i. e. 1.1 MPa. After the application of the stress the turgor pressure dropped within 15- 20 min of the application of all the concentrations of NaCl. The osmotic pressure of osmotically active solutes present in the cell wall, nwr was almost negligible i. e. 4 0.1 MPa, in mature cells and so could not contribute to turgor maiýtenance. The extent of decrease was proportional to the external stress of 25, 50 and 75 mol m-3 NaCl only. Turgor pressure recovery, due to osmotic adjustment, started after about 10-12 h of the stress initiation. Complete turgor recovery was achieved after 24-48 h of the onset of stress depending on the applied NaCl concentration. Tissue osmotic pressure increased continuously with time. An increase in the nw was inferred during the whole experimental period and after 6d of the stress application that appeared to correspond to the magnitude of external stress. The concentrations of major ions and sugars were determined to measure their contribution towards the osmotic adjustment. Under control conditions Na +, ci-, PO 4 3- ' so 4 2- , glucose, fructose and sucrose were present in small amounts, while, K+ and No 3- were the-major osmotica. Their concentrations were about 200. mol _m-3. After the stress a large increase in the concentrations of Na + and Cl was observed, the sucrose concentration increased to a small extent. However, other osmotica remained Uniform for whole of the experimental time. A small decrease was observed in k+ concentration in response to higher salt levels. volumetric elastic modulus, -c, of mature cells was remained unchanged by the salt stress. However, the apparent resistance of the root cortex to osmotically driven water flow increased with the increase in stress level. No conclusion could be drawn about the contribution of these parameters to the control of growth and to leaf water relations in the context of salt stress. The possible use of turgor pressure recovery in the mature cells was investigated for assessing the extent of salt tolerance of various Pakistani wheat varieties. These varieties were previously rated according to their performance in absolute grain yield in response to NaCl stress. No simple correlation was found.

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Deveson, M. R. « Effects of plant growth regulators on root growth and root/shoot integration in wheat (Triticum aestivum L.) ». Thesis, University of Reading, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376235.

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Livres sur le sujet "Wheat Growth"

NATO Advanced Research Workshop on Wheat Growth and Modelling (1984 Bristol, England). Wheat growth and modelling. New York : Plenum Press, 1985.

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Day, W., et R. K. Atkin, dir. Wheat Growth and Modelling. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-3665-3.

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Davies, Samuel. Soybean and wheat crops : Growth, fertilization, and yield. Hauppauge, NY : Nova Science Publishers, 2009.

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Rozenberg, Yoʼel. Sefer Ḥelev ḥiṭim yaśbiʻekha : Bo yevoʼaru gidre talush u-meḥubar be-ḥiṭim u-meḥubarim la-ḳarḳaʻ ha-nogʻin le-khamah dine ha-Torah ... Bruḳlin, Nyu Yorḳ : [Yoʼel Rozenberg], 2012.

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Wei, Yimin. Wachstumsbiologische Untersuchungen an deutschen und chinesischen Weizensorten. Berlin : In Kommission bei Duncker & Humblot, 1992.

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McCabe, Tomas P. A study of agronomic factors affecting aspects of winter wheat production systems and their financial implications. Dublin : University College Dublin, 1998.

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Olmstead, Alan L. The red queen and the hard reds : Productivity growth in American wheat, 1800-1940. Cambridge, MA : National Bureau of Economic Research, 2002.

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Gitau, Raphael. Trade and agricultural competitiveness for growth, food security and poverty reduction : A case of wheat and rice production in Kenya. Nairobi, Kenya : Tegemeo Institute of Agricultural Policy and Development, 2010.

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Deckard, E. L. Ḳunṭres Ḥelev ḥiṭim : Divre hitʻorerut li-vene Torah liḳrat yeme ḳetsir ḥiṭim she-memushemashim u-vaʼim she-yihyu zerizin ... New Jersey : ḥ. mo. l., 2005.

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Germida, J. J. Growth and nutrition of wheat as affected by interactions between VA mycorrhizae and plant growth-promoting rhizobacteria (PGPR) : Final report. [Regina, Sask.] : Saskatchewan Agriculture and Food, 1995.

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Chapitres de livres sur le sujet "Wheat Growth"

Lambers, H. « Respiratory Metabolism in Wheat ». Dans Wheat Growth and Modelling, 123–27. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-3665-3_11.

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Day, W. « Wheat Growth and Modelling : An Introduction ». Dans Wheat Growth and Modelling, 1–5. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-3665-3_1.

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Goudriaan, J., H. H. van Laar, H. van Keulen et W. Louwerse. « Photosynthesis, CO2 and Plant Production ». Dans Wheat Growth and Modelling, 107–22. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-3665-3_10.

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Spiertz, J. H. J., et J. Vos. « Grain Growth of Wheat and its Limitation by Carbohydrate and Nitrogen Supply ». Dans Wheat Growth and Modelling, 129–41. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-3665-3_12.

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Vos, J. « Aspects of Modelling Post-Floral Growth of Wheat and Calculations of the Effects of Temperature and Radiation ». Dans Wheat Growth and Modelling, 143–48. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-3665-3_13.

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Hunt, L. A. « Relationships between Photosynthesis, Transpiration and Nitrogen in the Flag and Penultimate Leaves of Wheat ». Dans Wheat Growth and Modelling, 149–56. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-3665-3_14.

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Austin, R. B. « Modelling the Effects on Grain Yield of Genetic Variation in Some Crop Characteristics ». Dans Wheat Growth and Modelling, 157–64. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-3665-3_15.

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Thorpe, M. R., et Alexander Lang. « A Description of Partitioning in Plants ». Dans Wheat Growth and Modelling, 165–77. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-3665-3_16.

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Hansen, G. K., et H. Svendsen. « Assimilate Partitioning and Utilization During Vegetative Growth ». Dans Wheat Growth and Modelling, 179–84. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-3665-3_17.

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Passioura, J. B. « Roots and Water Economy of Wheat ». Dans Wheat Growth and Modelling, 185–98. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-3665-3_18.

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Actes de conférences sur le sujet "Wheat Growth"

Alharbi, Najmah, Ji Zhou et Wenija Wang. « Automatic Counting of Wheat Spikes from Wheat Growth Images ». Dans 7th International Conference on Pattern Recognition Applications and Methods. SCITEPRESS - Science and Technology Publications, 2018. http://dx.doi.org/10.5220/0006580403460355.

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Kim, Yihyun, Sukyoung Hong, Kyoungdo Lee, Thomas Jackson, Rajat Bindlish, Gunho Jung, Soyeong Jang et And Sangil Na. « Estimating wheat growth for radar vegetation indices ». Dans IGARSS 2013 - 2013 IEEE International Geoscience and Remote Sensing Symposium. IEEE, 2013. http://dx.doi.org/10.1109/igarss.2013.6723512.

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Yan, Zhu, Liu Hui, Tang Liang, Tan Zihui, Chen Guoqing et Cao Weixing. « Modeling Leaf Length Growth and Leaf Shape in Winter Wheat ». Dans 2006 International Symposium on Plant Growth Modeling, Simulation, Visualization and Applications (PMA). IEEE, 2006. http://dx.doi.org/10.1109/pma.2006.47.

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Dong, Yingying, Jihua Wang, Cunjun Li, Qian Wang et Wenjiang Huang. « Estimating the Leaf Area Index of Winter Wheat Canopies with Crop Growth Model CERES-Wheat ». Dans 2012 2nd International Conference on Remote Sensing, Environment and Transportation Engineering (RSETE). IEEE, 2012. http://dx.doi.org/10.1109/rsete.2012.6260560.

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Kalra, Naveen, P. K. Aggarwal, A. K. Singh, V. K. Dadhwal, V. K. Sehgal, R. C. Harith et S. K. Sharma. « Methodology for national wheat yield forecast using wheat growth model, WTGROWS, and remote sensing inputs ». Dans Asia-Pacific Remote Sensing Symposium, sous la direction de Robert J. Kuligowski, Jai S. Parihar et Genya Saito. SPIE, 2006. http://dx.doi.org/10.1117/12.697698.

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Xu, Xingang, Jihua Wang, Cunjun Li, Xiaoyu Song et Wenjiang Huang. « Estimating growth height of winter wheat with remote sensing ». Dans Remote Sensing, sous la direction de Christopher M. U. Neale et Antonino Maltese. SPIE, 2010. http://dx.doi.org/10.1117/12.864909.

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Davidyants, E. S. « Еffect of phenolic growth regulators on winter wheat crops ». Dans CURRENT STATE, PROBLEMS AND PROSPECTS OF THE DEVELOPMENT OF AGRARIAN SCIENCE. Federal State Budget Scientific Institution “Research Institute of Agriculture of Crimea”, 2019. http://dx.doi.org/10.33952/09.09.2019.11.

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Chen, Yan Hua, Qian Zhang, Bao Guo Li et Bao Gui Zhang. « Characterizing Wheat Root Branching Using a Markov Chain Approach ». Dans 2006 International Symposium on Plant Growth Modeling, Simulation, Visualization and Applications (PMA). IEEE, 2006. http://dx.doi.org/10.1109/pma.2006.31.

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Ivanova, Desislava. « CHALLENGES FOR THE WHEAT MARKET IN THE BLACK SEA REGION UNDER CОVID-19 ». Dans AGRIBUSINESS AND RURAL AREAS - ECONOMY, INNOVATION AND GROWTH 2021. University publishing house "Science and Economics", University of Economics - Varna, 2021. http://dx.doi.org/10.36997/ara2021.144.

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Under COVID-19, the world is facing unclear circumstances as a result of the global political, economic, social and financial recession caused by the pandemic. The overpopulation of certain regions as a result of globalization leads to problems related to the nutrition of the population and food security. The Black Sea region, with its strategic location, is an essential market both for the production and for the supply of raw materials to the regions affected by poverty and also for the international grain trade and in particular for the wheat. The report presents the main trends in the wheat market within the Black Sea region and argues the problems and challenges, which the grain trade is facing after the beginning of the COVID- 19 pandemic.

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Fang, Yao, Wang Wenyong, Zhong Shaochun, Tian Ye et Ye Linan. « Modeling and Research on Growth of Virtual Plant Wheat Roots ». Dans 2009 International Forum on Information Technology and Applications (IFITA). IEEE, 2009. http://dx.doi.org/10.1109/ifita.2009.433.

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Rapports d'organisations sur le sujet "Wheat Growth"

Olmstead, Alan, et Paul Rhode. The Red Queen and the Hard Reds : Productivity Growth in American Wheat, 1800-1940. Cambridge, MA : National Bureau of Economic Research, mars 2002. http://dx.doi.org/10.3386/w8863.

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Palta, J. Impact of a simulated nuclear winter environment on growth development and productivity of potatoes, winter wheat, pines and soybeans. Office of Scientific and Technical Information (OSTI), janvier 1988. http://dx.doi.org/10.2172/5474568.

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Blum, Abraham, Henry T. Nguyen et N. Y. Klueva. The Genetics of Heat Shock Proteins in Wheat in Relation to Heat Tolerance and Yield. United States Department of Agriculture, août 1993. http://dx.doi.org/10.32747/1993.7568105.bard.

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Fifty six diverse spring wheat cultivars were evaluated for genetic variation and heritability for thermotolerance in terms of cell-membrane stability (CMS) and triphenyl tetrazolium chloride (TTC) reduction. The most divergent cultivars for thermotolerance (Danbata-tolerant and Nacozari-susceptible) were crossed to develop an F8 random onbred line (RIL) population. This population was evaluated for co-segragation in CMS, yield under heat stress and HSP accumulation. Further studies of thermotolerance in relations to HSP and the expression of heterosis for growth under heat stress were performed with F1 hybrids of wheat and their parental cultivars. CMS in 95 RILs ranged from 76.5% to 22.4% with 71.5% and 31.3% in Danbata and Nacozari, respectively. The population segregated with a normal distribution across the full range of the parental values. Yield and biomass under non-stress conditions during the normal winter season at Bet Dagan dit not differ between the two parental cultivar, but the range of segregation for these traits in 138 RILs was very high and distinctly transgressive with a CV of 35.3% and 42.4% among lines for biomass and yield, respectively. Mean biomass and yield of the population was reduced about twofold when grown under the hot summer conditions (irrigated) at Bet Dagan. Segregation for biomass and yield was decreased relative to the normal winter conditions with CV of 20.2% and 23.3% among lines for biomass and yield, respectively. However, contrary to non-stress conditions, the parental cultivars differed about twofold in biomass and yield under heat stress and the population segregated with normal distribution across the full range of this difference. CMS was highly and positively correlated across 79 RILs with biomass (r=0.62**) and yield (r=0.58**) under heat stress. No such correlation was obtained under the normal winter conditions. All RILs expressed a set of HSPs under heat shock (37oC for 2 h). No variation was detected among RILs in high molecular weight HSP isoforms and they were similar to the patterns of the parental cultivars. There was a surprisingly low variability in low molecular weight HSP isoforms. Only one low molecular weight and Nacozari-specific HSP isoform (belonging to HSP 16.9 family) appeared to segregate among all RILs, but it was not quantitatively correlated with any parameter of plant production under heat stress or with CMS in this population. It is concluded that this Danbata/Nacozari F8 RIL population co-segregated well for thermotolerance and yield under heat stress and that CMS could predict the relative productivity of lines under chronic heat stress. Regretfully this population did not express meaningful variability for HSP accumulation under heat shock and therefore no role could be seen for HSP in the heat tolerance of this population. In the study of seven F1 hybrids and their parent cultivars it was found that heterosis (superiority of the F1 over the best parent) for CMs was generally lower than that for growth under heat stress. Hybrids varied in the rate of heterosis for growth at normal (15o/25o) and at high (25o/35o) temperatures. In certain hybrids heterosis for growth significantly increased at high temperature as compared with normal temperature, suggesting temperature-dependent heterosis. Generally, under normal temperature, only limited qualitative variation was detected in the patterns of protein synthesis in four wheat hybrids and their parents. However, a singular protein (C47/5.88) was specifically expressed only in the most heterotic hybrid at normal temperature but not in its parent cultivars. Parental cultivars were significantly different in the sets of synthesized HSP at 37o. No qualitative changes in the patterns of protein expression under heat stress were correlated with heterosis. However, a quantitative increase in certain low molecular weight HSP (mainly H14/5.5 and H14.5.6, belonging to the HSP16.9 family) was positively associated with greater heterosis for growth at high temperature. None of these proteins were correlated with CMS across hybrids. These results support the concept of temperature-dependent heterosis for growth and a possible role for HSP 16.9 family in this respect. Finally, when all experiments are viewed together, it is encouraging to find that genetic variation in wheat yield under chronic heat stress is associated with and well predicted by CMS as an assay of thermotolerance. On the other hand the results for HSP are elusive. While very low genetic variation was expressed for HSP in the RIL population, a unique low molecular weight HSP (of the HSP 16.9 family) could be associated with temperature dependant heterosis for growth.

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Jander, Georg, et Daniel Chamovitz. Investigation of growth regulation by maize benzoxazinoid breakdown products. United States Department of Agriculture, janvier 2015. http://dx.doi.org/10.32747/2015.7600031.bard.

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Introduction Previous research had suggested that benzoxazinoids, a class of defensive metabolites found in maize, wheat, rye, and wild barley, are not only direct insect deterrents, but also influence other areas of plant metabolism. In particular, the benzoxazinoid 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxa- zin-3(4H)- one (DIMBOA) was implicated in: (i) altering plant growth by interfering with auxin signaling, and (ii) leading to the induction of gene expression changes and secondary plant defense responses. The overall goal of this proposal was to identify mechanisms by which benzoxazinoids influence other aspects of plant growth and defense. Specifically, the following hypotheses were proposed to be tested as part of an approved BARD proposal: Benzoxazinoid breakdown products directly interfere with auxin perception Global changes in maize and barley gene expression are induced by benzoxazinoid activation. There is natural variation in the maize photomorphogenic response to benzoxazinoids. Although the initial proposal included experiments with both maize and barley, there were some technical difficulties with the proposed transgenic barley experiments and most of the experimental results were generated with maize. Summary of major findings Previous research by other labs, involving both maize and other plant species, had suggested that DIMBOA alters plant growth by interfering with auxin signaling. However, experiments conducted in both the Chamovitz and the Jander labs using Arabidopsis and maize, respectively, were unable to confirm previously published reports of exogenously added DIMBOA effects on auxin signaling. Nevertheless, analysis of bx1 and bx2 maize mutant lines, which have almost no detectable benzoxazinoids, showed altered responses to blue light signaling. Transcriptomic analysis of maize mutant lines, variation in inbred lines, and responses to exogenously added DIMBOA showed alteration in the transcription of a blue light receptor, which is required for plant growth responses. This finding provides a novel mechanistic explanation of the trade-off between growth and defense that is often observed in plants. Experiments by the Jander lab and others had demonstrated that DIMBOA not only has direct toxicity against insect pests and microbial pathogens, but also induces the formation of callose in both maize and wheat. In the current project, non-targeted metabolomic assays of wildtype maize and mutants with defects in benzoxazinoid biosynthesis were used to identify unrelated metabolites that are regulated in a benzoxazinoid-dependent manner. Further investigation identified a subset of these DIMBOA-responsive compounds as catechol, as well as its glycosylated and acetylated derivatives. Analysis of co-expression data identified indole-3-glycerol phosphate synthase (IGPS) as a possible regulator of benzoxazinoid biosynthesis in maize. In the current project, enzymatic activity of three predicted maize IGPS genes was confirmed by heterologous expression. Transposon knockout mutations confirmed the function of the maize genes in benzoxazinoid biosynthesis. Sub-cellular localization studies showed that the three maize IGPS proteins are co-localized in the plastids, together with BX1 and BX2, two previously known enzymes of the benzoxazinoid biosynthesis pathway. Implications Benzoxazinoids are among the most abundant and effective defensive metabolites in maize, wheat, and rye. Although there is considerable with-in species variation in benzoxazinoid content, very little is known about the regulation of this variation and the specific effects on plant growth and defense. The results of this research provide further insight into the complex functions of maize benzoxazinoids, which are not only toxic to pests and pathogens, but also regulate plant growth and other defense responses. Knowledge gained through the current project will make it possible to engineer benzoxazinoid biosynthesis in a more targeted manner to produce pest-tolerant crops without negative effects on growth and yield.

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Bonfil, David J., Daniel S. Long et Yafit Cohen. Remote Sensing of Crop Physiological Parameters for Improved Nitrogen Management in Semi-Arid Wheat Production Systems. United States Department of Agriculture, janvier 2008. http://dx.doi.org/10.32747/2008.7696531.bard.

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To reduce financial risk and N losses to the environment, fertilization methods are needed that improve NUE and increase the quality of wheat. In the literature, ample attention is given to grid-based and zone-based soil testing to determine the soil N available early in the growing season. Plus, information is available on in-season N topdressing applications as a means of improving GPC. However, the vast majority of research has focused on wheat that is grown under N limiting conditions in sub-humid regions and irrigated fields. Less attention has been given to wheat in dryland that is water limited. The objectives of this study were to: (1) determine accuracy in determining GPC of HRSW in Israel and SWWW in Oregon using on-combine optical sensors under field conditions; (2) develop a quantitative relationship between image spectral reflectance and effective crop physiological parameters; (3) develop an operational precision N management procedure that combines variable-rate N recommendations at planting as derived from maps of grain yield, GPC, and test weight; and at mid-season as derived from quantitative relationships, remote sensing, and the DSS; and (4) address the economic and technology-transfer aspects of producers’ needs. Results from the research suggest that optical sensing and the DSS can be used for estimating the N status of dryland wheat and deciding whether additional N is needed to improve GPC. Significant findings include: 1. In-line NIR reflectance spectroscopy can be used to rapidly and accurately (SEP <5.0 mg g⁻¹) measure GPC of a grain stream conveyed by an auger. 2. On-combine NIR spectroscopy can be used to accurately estimate (R² < 0.88) grain test weight across fields. 3. Precision N management based on N removal increases GPC, grain yield, and profitability in rainfed wheat. 4. Hyperspectral SI and partial least squares (PLS) models have excellent potential for estimation of biomass, and water and N contents of wheat. 5. A novel heading index can be used to monitor spike emergence of wheat with classification accuracy between 53 and 83%. 6. Index MCARI/MTVI2 promises to improve remote sensing of wheat N status where water- not soil N fertility, is the main driver of plant growth. Important features include: (a) computable from commercial aerospace imagery that include the red edge waveband, (b) sensitive to Chl and resistant to variation in crop biomass, and (c) accommodates variation in soil reflectance. Findings #1 and #2 above enable growers to further implement an efficient, low cost PNM approach using commercially available on-combine optical sensors. Finding #3 suggests that profit opportunities may exist from PNM based on information from on-combine sensing and aerospace remote sensing. Finding #4, with its emphasis on data retrieval and accuracy, enhances the potential usefulness of a DSS as a tool for field crop management. Finding #5 enables land managers to use a DSS to ascertain at mid-season whether a wheat crop should be harvested for grain or forage. Finding #6a expands potential commercial opportunities of MS imagery and thus has special importance to a majority of aerospace imaging firms specializing in the acquisition and utilization of these data. Finding #6b on index MCARI/MVTI2 has great potential to expand use of ground-based sensing and in-season N management to millions of hectares of land in semiarid environments where water- not N, is the main determinant of grain yield. Finding #6c demonstrates that MCARI/MTVI2 may alleviate the requirement of multiple N-rich reference strips to account for soil differences within farm fields. This simplicity will be less demanding of grower resources, promising substantially greater acceptance of sensing technologies for in-season N management.

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Blomstrom, Magnus, Robert Lipsey et Mario Zejan. What Explains Developing Country Growth ? Cambridge, MA : National Bureau of Economic Research, août 1992. http://dx.doi.org/10.3386/w4132.

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Phillips, Donald, et Yoram Kapulnik. Using Flavonoids to Control in vitro Development of Vesicular Arbuscular Mycorrhizal Fungi. United States Department of Agriculture, janvier 1995. http://dx.doi.org/10.32747/1995.7613012.bard.

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Vesicular-arbuscular mycorrhizal (VAM) fungi and other beneficial rhizosphere microorganisms, such as Rhizobium bacteria, must locate and infect a host plant before either symbiont profits. Although benefits of the VAM association for increased phosphorous uptake have been widely documented, attempts to improve the fungus and to produce agronomically useful amounts of inoculum have failed due to a lack of in vitro production methods. This project was designed to extend our prior observation that the alfalfa flavonoid quercetin promoted spore germination and hyphal growth of VAM fungi in the absence of a host plant. On the Israeli side of the project, a detailed examination of changes in flavonoids and flavonoid-biosynthetic enzymes during the early stages of VAM development in alfalfa found that VAM fungi elicited and then suppressed transcription of a plant gene coding for chalcone isomerase, which normally is associated with pathogenic infections. US workers collaborated in the identification of flavonoid compounds that appeared during VAM development. On the US side, an in vitro system for testing the effects of plant compounds on fungal spore germination and hyphal growth was developed for use, and intensive analyses of natural products released from alfalfa seedlings grown in the presence and absence of microorganisms were conducted. Two betaines, trigonelline and stachydrine, were identified as being released from alfalfa seeds in much higher concentrations than flavonoids, and these compounds functioned as transcriptional signals to another alfalfa microsymbiont, Rhizobium meliloti. However, these betaines had no effect on VAM spore germination or hyphal growth i vitro. Experiments showed that symbiotic bacteria elicited exudation of the isoflavonoids medicarpin and coumestrol from legume roots, but neither compound promoted growth or germination of VAM fungi in vitro. Attempts to look directly in alfalfa rhizosphere soil for microbiologically active plant products measured a gradient of nod-gene-inducing activity in R. meliloti, but no novel compounds were identified for testing in the VAM fungal system in vitro. Israeli field experiments on agricultural applications of VAM were very successful and developed methods for using VAM to overcome stunting in peanuts and garlic grown in Israel. In addition, deleterious effects of soil solarization on growth of onion, carrot and wheat were linked to effects on VAM fungi. A collaborative combination of basic and applied approaches toward enhancing the agronomic benefits of VAM asociations produced new knowledge on symbiotic biology and successful methods for using VAM inocula under field conditions

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Rajan, Raghuram, et Arvind Subramanian. What Undermines Aid's Impact on Growth ? Cambridge, MA : National Bureau of Economic Research, octobre 2005. http://dx.doi.org/10.3386/w11657.

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McMillan, Margaret, et Kenneth Harttgen. What is driving the 'African Growth Miracle' ? Cambridge, MA : National Bureau of Economic Research, avril 2014. http://dx.doi.org/10.3386/w20077.

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Crowley, David E., Dror Minz et Yitzhak Hadar. Shaping Plant Beneficial Rhizosphere Communities. United States Department of Agriculture, juillet 2013. http://dx.doi.org/10.32747/2013.7594387.bard.

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PGPR bacteria include taxonomically diverse bacterial species that function for improving plant mineral nutrition, stress tolerance, and disease suppression. A number of PGPR are being developed and commercialized as soil and seed inoculants, but to date, their interactions with resident bacterial populations are still poorly understood, and-almost nothing is known about the effects of soil management practices on their population size and activities. To this end, the original objectives of this research project were: 1) To examine microbial community interactions with plant-growth-promoting rhizobacteria (PGPR) and their plant hosts. 2) To explore the factors that affect PGPR population size and activity on plant root surfaces. In our original proposal, we initially prqposed the use oflow-resolution methods mainly involving the use of PCR-DGGE and PLFA profiles of community structure. However, early in the project we recognized that the methods for studying soil microbial communities were undergoing an exponential leap forward to much more high resolution methods using high-throughput sequencing. The application of these methods for studies on rhizosphere ecology thus became a central theme in these research project. Other related research by the US team focused on identifying PGPR bacterial strains and examining their effective population si~es that are required to enhance plant growth and on developing a simulation model that examines the process of root colonization. As summarized in the following report, we characterized the rhizosphere microbiome of four host plant species to determine the impact of the host (host signature effect) on resident versus active communities. Results of our studies showed a distinct plant host specific signature among wheat, maize, tomato and cucumber, based on the following three parameters: (I) each plant promoted the activity of a unique suite of soil bacterial populations; (2) significant variations were observed in the number and the degree of dominance of active populations; and (3)the level of contribution of active (rRNA-based) populations to the resident (DNA-based) community profiles. In the rhizoplane of all four plants a significant reduction of diversity was observed, relative to the bulk soil. Moreover, an increase in DNA-RNA correspondence indicated higher representation of active bacterial populations in the residing rhizoplane community. This research demonstrates that the host plant determines the bacterial community composition in its immediate vicinity, especially with respect to the active populations. Based on the studies from the US team, we suggest that the effective population size PGPR should be maintained at approximately 105 cells per gram of rhizosphere soil in the zone of elongation to obtain plant growth promotion effects, but emphasize that it is critical to also consider differences in the activity based on DNA-RNA correspondence. The results ofthis research provide fundamental new insight into the composition ofthe bacterial communities associated with plant roots, and the factors that affect their abundance and activity on root surfaces. Virtually all PGPR are multifunctional and may be expected to have diverse levels of activity with respect to production of plant growth hormones (regulation of root growth and architecture), suppression of stress ethylene (increased tolerance to drought and salinity), production of siderophores and antibiotics (disease suppression), and solubilization of phosphorus. The application of transcriptome methods pioneered in our research will ultimately lead to better understanding of how management practices such as use of compost and soil inoculants can be used to improve plant yields, stress tolerance, and disease resistance. As we look to the future, the use of metagenomic techniques combined with quantitative methods including microarrays, and quantitative peR methods that target specific genes should allow us to better classify, monitor, and manage the plant rhizosphere to improve crop yields in agricultural ecosystems. In addition, expression of several genes in rhizospheres of both cucumber and whet roots were identified, including mostly housekeeping genes. Denitrification, chemotaxis and motility genes were preferentially expressed in wheat while in cucumber roots bacterial genes involved in catalase, a large set of polysaccharide degradation and assimilatory sulfate reduction genes were preferentially expressed.

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