The response of transgenic strawberry plants overexpressing a drought induced gene to water stress

Transgenic strawberry plants expressing a chitinase gene were evaluated for their performance during water stress. Transgenic and non-transgenic plants were assigned to three different soil water contents (SWC). They were kept under well-watered, moderately watered or stressed water conditions. At fi nal stage of experiment, dry matter components, leaf area, photosynthesis rate, water-use effi ciency (WUE) and water use per leaf area (WULA) were measured. Transgenic lines showed vigorous growth as compared with non-transgenic plants. Leaf area (LA), leaf dry matter (LDM), root dry matter (RDM) and total dry matter (TDM) of well-watered and water-stressed plants of transgenic lines were signifi cantly higher than those of non-transgenic plants. The WUE increased signifi cantly in transgenic lines, while water use (WU) per leaf area reduced in transgenic plants relative to control plants. Photosynthetic rates were not different between transgenic and non-transgenic plants. Soil water contents signifi cantly affected dry matter production, and photosynthetic rates. Transgenic plants also showed vigorous growth in comparison to non-transgenic plants when grown in vitro. Shoot, root and total fresh and dry weight of in vitro transgenic lines were significantly higher than those of nontransgenic plants

Investigating the effect of Regulated Deficit irrigation and Partial Root Dring on some physical and qualitative properties of rice grains and Nitrogen Absorption in furrow cultivation

Due to drought crisis in recent years, the use of alternative cropping methods that saves water without any decrease in yield is increasing. Regulated deficit irrigation is a method of irrigation in which, by supplying part of the maximum crop requirement at specified times, water management is addressed and therefore the root zone is in a dry area most of the time. Using this method will partially stop the growth of the plant and usually decrease yield (Jovanovic et al., 2010). Root Partial Drying (PRD) is a modified form of the deficit, which includes watering one section of the root zone in each irrigation and dry up another side, so the moisture of this section before next irrigation largely come down (Ahmadi et al., 2010). In the root drying method, the roots of the plant simultaneously with soil drying with the production of Abscisic Acid, prevent leaf expansion and reduce stomatal conductance. Simultaneously with this process, the root in the wet part with adequate water uptake puts the plant in proper moisture (Yousri Ibrahim Atta, 2008). Abscisic acid is a plant hormone whose production is increased by root in dry soils and transported by water flow into the stem. (liu et al., 2008). On the other hand, The quality of production is as important in all crops and especially in rice production in Iran. (Salehifar  et al., 2009) In order to evaluate some of the physical and qualitative properties of rice grain and the amount of nitrogen uptake in rice (Hashemi variety) under different irrigation levels and comparing it with continuous waterlogging, an experiment was conducted during two years of cultivation of 2015 and 2016

Evaluating the SSM Model Efficiency in Simulating the Wheat Growth under Water Stress Conditions

IntroductionWheat (Triticum aestivum L.) has become very important as a valuable strategic product with high energy level. The importance of investigating environmental stresses and their role in predicting and evaluating the growth and crops yield is essential. A wide range of plant response to stress is extended to morphological, physiological and biochemical responses. Considering the rapid advancement in computer model development, plant growth models have emerged as a valuable tool to predict changes in production yield. These growth simulation models effectively incorporate the intricate influences of various factors, such as climate, soil characteristics, and management practices on crop yield. By doing so, they offer a cost-effective and time-efficient alternative to traditional field research methods. Material and MethodsThis research was conducted in the research farm of Varamin province, which has a silty loam soil texture. The latitude and longitude of the region are 35º 32ʹ N and 51º 64ʹ E, respectively. Its height above sea level is 21 meters. According to Demarten classification, Varamin has a temperate humid climate. The long-term mean temperature of Varamin is 11.18 ° C and the total long-term rainfall is 780 mm. In this study, in order to simulate irrigated wheat cv. Mehregan growth under drought stress, an experimental based on completely randomized blocks (CRBD) including: non-stress as control (NS), water stress at booting stage (WSB), water stress at flowering stage (WSF), water stress at milking stage (WSM) and water stress at doughing stage (WSD) with three replications during growth season 2019-2020 was carried out in Varamin, Iran. Crop growth simulation was done using SSM-wheat model. This model simulates growth and yield on a daily basis as a function of weather conditions, soil characteristics and crop management (cultivar, planting date, plant density, irrigation regime). Results and DiscussionBased on the results, the simulation of the phenological stages of irrigated wheat cv. Mehregan under water stress condition using SSM-wheat model showed that there was no difference between observed and simulated values. Summary, the values of day to termination of seed growth (TSG) were observed under non- stress, stress in the booting stage, flowering, milking and doughing of the grains, 222, 219, 219, 221, 221 days, respectively andsimulation values with 224, 221, 220, 221, respectively. However, with their simulation values, there were slight differences with 224, 221, 220, 221, respectively. Acceptable values of RMSE (11.7 g.m-2) and CV (3.5) indexes showed the high ability of the SSM model in simulating the grain yield of irrigated wheat cv. Mehregan under water stress conditions. Grain yield values were observed in non-stress conditions of 5783, water stress in booting, flowering, milking and doughing of the grain stages in 5423, 5160, 5006 and 5100 kg. h-1, respectively. While the simulated values were 5630, 5220, 4920, 4680 and 4880 kg. h-1, respectively. Based on the findings, observed and simulated values of leaf area index (LAI) were observed under water stress condition in the booting, flowering, milking and doughing of the grain stages (4.3 and 4.47), (4.33) and 4.46), (4.4 and 4.57) and (4.4 and 4.58) cm-2, respectively. Evaluation of the 1000-grain weight of irrigated wheat cv. Mehregan under the water stress showed that the SSM model was highly accurate. RMSE (4.6 g.m-2) and CV (1.8) values indicate the ability of the SSM model to simulate the 1000-grain weight of irrigated wheat cv. Mehregan. Also, the simulated values of the harvest index were 34.7 % in non-stress conditions, which decreased by 6 % compared to the observed value. Harvest index values were observed under water stress conditions in the in the booting, flowering, milking and doughing of the grain stages in 30.2, 29.3, 29.9 and 29.5 %, respectively. Compared to its observed values, it was reduced by 3, 3.5, 5, and 5.5 %, respectively. ConclusionBased on the findings, the slight difference between the observed and simulated values demonstrates the SSM model's capability to accurately capture water stress impacts on the phenological stages, grain yield, and yield components of irrigated wheat cv. Mehregan during critical growth stages, including booting, flowering, milking, and doughing. The results indicate that the SSM model is effective in simulating wheat growth under water stress conditions, showcasing its potential as a valuable tool for modeling irrigated wheat growth. The model's ability to account for water stress and its effects on various growth parameters makes it a reliable and efficient tool for predicting crop performance in water-limited environments

Daily heliotropic movements assist gas exchange and productive responses in DREB1A soybean plants under drought stress in the greenhouse.

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Estimating actual evapotranspiration using OLI images and SEBAL algorithm (Case study: Dasht-e Naz, Sari)

Estimation of evapotranspiration is,one of the main components of the hydrological cycle, and is essential for irrigation scheduling, water balance, irrigation system design and management and crop yields simulation. Unlike conventional methods remote sensing estimates evapotranspiration in different spatial scales. Therefore, the aim of this study is to estimate evapotranspiration using OLI sensor images and SEBAL algorithm in the Dasht-e-Naz area, Sari, Iran. To evaluate the results, evapotranspiration estimated by the reference method, Penman-Monteith-FAO, was compared with SEBAL algorithm. Strong and significant correlation was obtained between these two methods (R2=0.93), Low error of estimation by SEBAL compared with reference method (RMSE=1.14) and low absolute difference between the SEBAL and Penman-Monteith-FAO (MAE=0.96) indicates that there is a good match between estimated values by SEBAL algorithm and Penman-Monteith-FAO standard method. This study showed that OLI sensor images and SEBAL algorithm could satisfactorily estimate actual evapotranspiration in the Dasht-e-Naz area, Sari

Soil moisture monitoring by downscaling of remote sensing products using LST/VI space derived from MODIS products

Soil moisture (SM) has an important role in the earth's water cycle and is a key variable in water resources management. Considering the critical state of water resources in the Urmia Lake basin, northwest Iran, this study examined the potential for utilizing a variety of remote sensing data and products, in conjunction with a promising downscaling method, to monitor soil moisture with a reasonable spatial and temporal resolution, as a novel and effective tool for agricultural and water resource management. Accordingly, remote sensing products of surface soil moisture were scaled to MODIS's image scale (∼1 km) using the UCLA downscaling method and Temperature, Vegetation, Drought Index (TVDI) values obtained from the scattering space method. Results showed that the LPRM, ESA-CCI, and GLDAS downscaled images had the highest inverse correlation with the TVDI (best results) accordingly equal to −0.600, −0.787, and −0.630. Also, based on the evaluation of the obtained results with the ground stations data, the LPRM and the ESA-CCI downscaled images had the best statistical indices values accordingly in 2010 and 2014 that confirm the promising application of remote sensing soil moisture data (rLPRM (2010) = 0.92, MAELPRM (2010) = 4.14%, RMSELPRM (2010) = 6.39% and rESA-CCI (2014) = 0.7, MAEESA-CCI (2014) = 2.23%, RMSEESA-CCI (2014) = 2.59%). HIGHLIGHTS Soil moisture spatio-temporal monitoring was carried out as an important step in the path of sustainable development.; The research conducted on the downscaling of soil moisture radar products using MODIS images alongside scattering space and UCLA methods proved their ability in various land uses.; LPRM and ESA-CCI products were found to have the highest accuracy in monitoring soil moisture in the Urmia Lake basin.

The effect of alternate partial root-zone drying and deficit irrigation on the yield, quality, and physiochemical parameters of milled rice

While paddy fields produce a high yield, they also require a large amount of water and produce a significant amount of methane. Therefore, the adoption of water-saving irrigation techniques for rice cultivation is critical. Furrowed rice farming may be a viable alternative to paddy rice cultivation. The objective of the present study was to evaluate the impact of alternate partial root-zone drying irrigation on rice yield, milled rice quality, and cooking quality under furrow rice cultivation. A two-year field trial was conducted on a local rice cultivar, Tarom Hashemi, in 2015 and 2016. Seven water regimes, including three levels of regulated deficit irrigation (RDI), three levels of alternate partial root-zone drying irrigation (APRDI), and conventional flooding irrigation (CFI), were used in this study. In RDI and APRDI treatments, plots were irrigated when soil matric potential had reached −0.1 (RDI1 and APRDI1), −0.3 (RDI3 and APRDI3), and −0.6 bar (RDI6 and APRDI6). RDI1 and APRDI1 treatments produced milled rice yield similar to the CFI, while irrigation water productivity (IWP) was significantly higher by 22.9% and 45.7%, respectively. Regardless of the soil water potential, the IWP in APRDI treatments was 16% higher than that of RDI treatments. Severe water stress (RDI6 and APRDI6) caused a marked increase in amylose content and alkali spreading value of milled rice resulting in improved cooking quality. Nitrogen uptake in APRDI treatments was 2% higher than that of RDI treatments. On average, methane emission per milled grain yield declined by 77.9% and 78.7% in RDI and APRDI treatments, respectively. Our data indicate that the expensive and laborious practice of puddling can be avoided to increase water productivity and improve rice quality without sacrificing yield. The results also show that furrow rice cultivation could significantly reduce the methane emission contribution of rice production