Effect Of Moisture Stress Research Articles

Identification of most important rice root morphological markers in response to contrasting moisture regimes under vegetative stage drought

The experiment was carried out to examine the effect of moisture stress (drought) on different root traits, rooting pattern and to identify important root morphological markers contributing to stress tolerance. Moisture stress was imposed on 21 days old seedlings of selected rice genotypes grown in PVC cylinders. Samplings were done at 10 and 20 days after imposition of stress to examine the effect of stress on root growth and development. Results revealed that rate of assimilate allocation impeded more under 20 days stress (severe) than in 10 days stress (moderate) in terms of enhanced root: shoot ratio, maximum root length to shoot length ratio and root volume. Magnitude of trait variation among genotypes was more pronounced under severe stress than under moderate stress. The root: shoot ratio, maximum root length to shoot length ratio and root volume were observed to be the most crucial morphological markers in determining drought tolerance in rice genotypes analyzed through biplot analysis. Among the thirteen genotypes tested, AC-42994, AC-42997, AC-43020, CR-143-2-2, Ronga Bora and Bora were found to possess desirable root traits and these genotypes can be used in the breeding programme for enhancing drought tolerance in rice.

Predicting tree biomass growth in the temperate-boreal ecotone: Is tree size, age, competition, or climate response most important?

As global temperatures rise, variation in annual climate is also changing, with unknown consequences for forest biomes. Growing forests have the ability to capture atmospheric CO2 and thereby slow rising CO2 concentrations. Forests' ongoing ability to sequester C depends on how tree communities respond to changes in climate variation. Much of what we know about tree and forest response to climate variation comes from tree-ring records. Yet typical tree-ring datasets and models do not capture the diversity of climate responses that exist within and among trees and species. We address this issue using a model that estimates individual tree response to climate variables while accounting for variation in individuals' size, age, competitive status, and spatially structured latent covariates. Our model allows for inference about variance within and among species. We quantify how variables influence aboveground biomass growth of individual trees from a representative sample of 15 northern or southern tree species growing in a transition zone between boreal and temperate biomes. Individual trees varied in their growth response to fluctuating mean annual temperature and summer moisture stress. The variation among individuals within a species was wider than mean differences among species. The effects of mean temperature and summer moisture stress interacted, such that warm years produced positive responses to summer moisture availability and cool years produced negative responses. As climate models project significant increases in annual temperatures, growth of species like Acer saccharum, Quercus rubra, and Picea glauca will vary more in response to summer moisture stress than in the past. The magnitude of biomass growth variation in response to annual climate was 92-95% smaller than responses to tree size and age. This means that measuring or predicting the physical structure of current and future forests could tell us more about future C dynamics than growth responses related to climate change alone.

Effect of Soil Moisture Stress against Irrigated Condition on Tossa Jute

Effect of Soil Moisture Stress against Irrigated Condition on Tossa Jute Drought is worldwide major abiotic stress in agriculture which affecting yield and yield stability of food cereals and this stress acts simultaneously on many traits leading to a decrease in total biomass. Approximately 16% of India’s geographic area, mostly arid, semi-arid and sub-humid is drought prone area. The main reason of drought is irregular rainfall, deforestation, industrialization, wide variation in climatic conditions etc..

Potato Production under Drought Conditions: Identification of Adaptive Traits

Globally, potato is the third most important food crop after rice and wheat in terms of consumption. It is fast maturing, versatile in use and grows in a wide range of environments from sea level up to about 4700 metres above sea level and from Southern Chile to Greenland. Currently, potato production is rapidly expanding beyond the traditional high potential areas. This is mostly due to expanding world population accompanied by increasing food demand. However, potato is relatively susceptible to yield loss due to drought. Unfortunately, the extent, frequency and severity of drought occurrences have been increasing globally due to climate change. In order to feed the ever-increasing global population, increasing drought tolerance or resistance in potato through breeding is essential. For this to be successful, plant traits associated with drought tolerance or resistance need to be accurately identified and selected. Previously, water use efficiency (WUE) was identified as the most promising trait for selecting drought tolerant potato clones. This review also looks at the effect of moisture stress on potato growth, development and production; plant emergence and tuberization were identified as two critical periods when water stress mostly affect final tuber yield. Possibilities of conventional breeding as well as marker assisted breeding to increase drought resistance or tolerance were explored.

Effect of moisture stress and fungicide on biochemical traits and yield of soybean

A field experiment was conducted at University of Agricultural Sciences, Dharwad during kharif 2012 and 2013 under rainout shelterto study the influence of fungicide (Opera 18.3% SE) in improving yield by recovering biochemical traitsin moisture stressed soybean. The results revealed that in all the four moisture stress treatments viz., withholding water for 0, 5, 10 and 15 days imposed on 40 DAS, application of fungicide opera recorded high chlorophyll, soluble protein and less proline content withreduced membrane injury over their respective counterparts without fungicide application. Further the yield in moisture stress for 5, 10 and 15 days without fungicide treatment (3902, 3614 and 3902 kg/ha, respectively) was significantly reduced compared to their respective counterparts with fungicide treatment (3910, 4075 and 4224 kg/ha, respectively).

土壤水分胁迫对设施番茄根系及地上部生长的影响

土壤水分胁迫对设施番茄根系及地上部生长的影响

Remote sensing of interannual boreal forest NDVI in relation to climatic conditions in interior Alaska

Climate has warmed substantially in interior Alaska and several remote sensing studies have documented a decadal-scale decline in the normalized difference vegetation index (NDVI) termed a ‘browning trend’. Reduced summer soil moisture due to changing climatic factors such as earlier springs, less snowpack, and summer drought may reduce boreal productivity and NDVI. However, the relative importance of these climatic factors is poorly understood in boreal interior Alaska. In this study, I used the remotely sensed peak summer NDVI as an index of boreal productivity at 250 m pixel size from 2000 to 2014. Maximum summer NDVI was related to last day of spring snow, early spring snow water equivalent (SWE), and a summer moisture index. There was no significant correlation between early spring SWE and peak summer NDVI. There was a significant correlation between the last day of spring snow and peak summer NDVI, but only for a few higher elevation stations. This was likely due to snowmelt occurring later at higher elevations, thus having a greater effect on summer soil moisture relative to lower elevation sites. For most of boreal interior Alaska, summer drought was likely the dominant control on peak summer NDVI and this effect may persist for several years. Peak summer NDVI declined at all 26 stations after the 2004 drought, and the decline persisted for 2 years at all stations. Due to the shallow rooting zone of most boreal plants, even cool and moist sites at lower elevations are likely vulnerable to drought. For example the peak summer NDVI response following the 2004 drought was similar for adjacent cold and warm watershed basins. Thus, if frequent and severe summer droughts continue, moisture stress effects are likely to be widespread and prolonged throughout most of interior boreal Alaska, including relatively cool, moist sites regardless of spring snowpack conditions or spring phenology.

Uptake and translocation of imidacloprid, clothianidin and flupyradifurone in seed-treated soybeans.

Seed treatment insecticides have become a popular management option for early-season insect control. This study investigated the total uptake and translocation of seed-applied [(14) C]imidacloprid, [(14) C]clothianidin and [(14) C]flupyradifurone into different plant parts in three soybean vegetative stages (VC, V1 and V2). The effects of soil moisture stress on insecticide uptake and translocation were also assessed among treatments. We hypothesized that (1) uptake and translocation would be different among the insecticides owing to differences in water solubility, and (2) moisture stress would increase insecticide uptake and translocation. Uptake and translocation did not follow a clear trend in the three vegetative stages. Initially, flupyradifurone uptake was greater than clothianidin uptake in VC soybeans. In V1 soybeans, differences in uptake among the three insecticides were not apparent and unaffected by soil moisture stress. Clothianidin was negatively affected by soil moisture stress in V2 soybeans, while imidacloprid and flupyradifurone were unaffected. Specifically, soil moisture stress had a positive effect on the distribution of flupyradifurone in leaves. This was not observed with the neonicotinoids. This study enhances our understanding of the uptake and distribution of insecticides used as seed treatments in soybean. The uptake and translocation of these insecticides differed in response to soil moisture stress. © 2015 Society of Chemical Industry.

Understanding moisture stress on light use efficiency across terrestrial ecosystems based on global flux and remote‐sensing data

AbstractLight use efficiency (LUE) is a key biophysical parameter characterizing the ability of plants to convert absorbed light to carbohydrate. However, the environmental regulations on LUE, especially moisture stress, are poorly understood, leading to large uncertainties in primary productivity estimated by LUE models. The objective of this study is to investigate the effects of moisture stress on LUE for a wide range of ecosystems on daily, 8 day, and monthly scales. Using the FLUXNET and Moderate Resolution Imagine Spectroradiometer data, we evaluated moisture stress along the soil‐plant‐atmosphere continuum, including soil water content (SWC) and soil water saturation (SWS), land surface wetness index (LSWI) and plant evaporative fraction (EF), and precipitation and daytime atmospheric vapor pressure deficit (VPD). We found that LUE was most responsive to plant moisture indicators (EF and LSWI), least responsive to soil moisture (SWC and SWS) variations with the atmospheric indicator (VPD) falling in between. LUE showed higher sensitivity to SWC than VPD only for grassland ecosystems. For evergreen forest, LUE had better association with VPD than LSWI. All moisture indicators (except soil indicators) were generally less effective in affecting LUE on the daily and 8 day scales than on the monthly scale. Our study highlights the complexity of moisture stress on LUE and suggests that a single moisture indicator or function in LUE models is not sufficient to capture the diverse responses of vegetation to moisture stress. LUE models should consider the variability identified in this study to more realistically reflect the environmental controls on ecosystem functions.

In vivo evaluation of wheat (Triticum aestivum L.) cultivars for moisture stress

In Ethiopia, wheat productivity is constrained by water stress especially at germination and seedling stage. The objective of this research was to determine the effect of moisture stress on bread wheat (Triticum aestivum) cultivars. Four wheat cultivars (Danda’a, Kubsa, Huluka and Local) were treated with six levels of water stress (0, 50, 100, 150, 200 and 250 g L-1) using PEG-6000. The experiment was arranged factorally in completely randomized design with three replications. Data on germination and growth indices were collected and analyzed using one way ANOVA. The result revealed that highest germination percentage (99.7%), germination rate (14.6 plants day-1) and seedling vigor index (9.67) were obtained from the local cultivar. Progressive increase in water stress had also significantly reduced germination indices. There was no significant difference among the cultivars in producing taller root and shoot length. The local cultivar had significantly produced highest root number (4.3 plant-1), shoot fresh weight (0.214 g), seedling fresh (0.314 g) and dry weight (0.097 g). Even though, all the growth parameters of wheat cultivars showed a diminishing trend with increasing the level of PEG-6000 induced water stress, a highly significant decrease in the parameters were observed starting from 150 g L-1 PEG concentration. Higher shoot length inhibition was observed for Danda’a cultivar followed by Huluka. Huluka’s root growth was more inhibited than Danda’a. According to the growth and germination indices results, the local cultivar is the drought tolerant wheat cultivar. DOI: http://dx.doi.org/10.3329/ijarit.v4i2.22651 Int. J. Agril. Res. Innov. & Tech. 4 (2): 55-60, December, 2014

Variability in Response of Groundnut (Arachis hypogaeaL.) Genotypes to Moisture Stress and Stress Release

Groundnut (Arachis hypogaea L.) is an important oilseed cash crop and an erratic rainfall with prolonged dry spells during critical pheno-phases of reproductive stages affects its yield. A field trial was carried out with groundnut genotypes-JL-24, ICGV 91114, Narayani, Abhaya, Dharani and Greeshma to study the variability in morphological, biochemical and yield traits to moisture stress at flowering stage. Significant reduction in growth and yield components of all the selected groundnut genotypes was observed due to moisture stress. ANOVA for pod weight, seed weight, 100 seed weight, harvest index, total biomass were found to be highly significant (p<0.01) for genotypes, moisture levels and their interactions. Impact of moisture stress on plant height, leaf area, leaf and shoot biomass was lowest in Dharani and osmoprotectant-proline and activity of antioxidant enzymes-SOD and POD were higher in Dharani. The yield performance of Narayani, Abhaya, Dharani were similar as well as superior under control condition where as under moisture stress conditions Dharani recorded highest seed yield, HI with lowest reduction in seed number and 100 seed weight. Under control conditions seed yield had significant positive correlation with pod number, pod weight and seed number whereas under moisture stress conditions with SOD, POD, leaf area, leaf dry weight, pod weight, seed number, 100 seed weight and shelling %. The groundnut genotype Dharani performed best under both control and moisture stress conditions as its high anti-oxidative enzyme activity and proline content might have been ameliorated the ill effects of moisture stress.

Effects of Acute Moisture Stress on Creeping Bentgrass Cuticle Morphology and Associated Effects on Foliar Nitrogen Uptake

Foliar fertilization is a common practice to deliver nitrogen (N) to turfgrasses. The mechanisms of foliar applied nutrient uptake, particularly the effects of the leaf cuticle layer, have not been clearly characterized in turfgrasses. The objectives of this study were to determine the effect of acute moisture stress on the morphological and compositional components of the cuticle and the resulting effect on foliar-applied N absorption. Creeping bentgrass (Agrostis stolonifera L.) was irrigated to return 100% or 50% evapotranspiration rate (ET) for 10 days to examine cuticular modifications resulting from acute moisture stress and foliar N uptake with and without a surfactant. Acute water stress increased the total cuticle wax by 11%, mostly as a result of the compound 1-hexacosanol, and increased crystalloid density creating a rougher leaf surface. The 50% ET treatment significantly reduced recovery of 15N-labeled urea by 14%, which was attributed to the increased total cuticle wax and crystalloid density making the surface less receptive to foliar applications. The surfactant addition to the urea solution increased 15N-labeled urea recovery by 21% and absorption of 15N in 50% ET plants to levels consistent with the 100% ET plants. These results suggest that acute moisture stress modifies the cuticle wax load and morphology, thereby hindering foliar absorption; however, a surfactant addition can help to mitigate this effect and increase absorption of N.

Advances in Hygro-Thermal Deformation of Concrete Material

The development of concrete deformation is determined by the time depended distribution of temperature and humidity in concrete resulting form the variation of temperature and humidity and also their coupling effect, which also greatly influences the durability and service life of concrete. Therefore, the coupling effect of temperature-humidity variation must be considered when study the volume deformation of concrete. The studies related to the hygro-thermal deformation of concrete were reviewed and summarized, which included the research status of concrete deformation resulting from temperature and humidity, the coupled heat and moisture transfer model and the numerical simulation method. The research status and existing problems of hygro-thermal deformation of concrete were also analyzed in detail for promoting the investigation on the mechanism of volume deformation cracking and the durability of concrete material, which will benefit to the deformation prediction and crack control technology of engineering structure. Periodically variation of environmental temperature and humidity can be used to describe the seasonal or diurnal temperature-humidity changing of concrete materials and structures in the construction and service period of concrete structure. Consideration should also be given to "fatigue effect of heat and moisture stress" when study the deformation evolution and the damage mechanism of concrete crack.

English

A laboratory experiment was performed at Ambo University, Department of Plant Sciences in March 2014, to evaluate the effect of moisture stress on germination and seedling growths of highland maize cultivars. The experiment was arranged factorially in completely randomized design with three replications. Five highland maize cultivars (Hora, Wenchi, Jibat, Argene and Wabi) were exposed to six levels of water stress (0, 60, 120, 180, 240 and 300 g/L Polyethylene glycol 6000). The result revealed that no significant interactions exist between maize cultivars and moisture stress. However, cultivars varied significantly for germination percentage and rate, shoot and root lengths, root number, and shoot and root fresh weight. Increase in PEG 6000 concentrations decreased germination percentage and rate, where as shoot and root lengths decreased beyond 60 g/l. No significant differences were observed among 60, 120 and 180 g/L for shoot and root fresh and dry weights, and seedling fresh and dry weights. Maximum root number, root-to-shoot ratio and tolerance index was observed at 120 and 180, 240 and 60 g/L PEG, respectively. Hence, highland maize cultivars showed differential response in terms of germination and seedling growth with increased moisture stress, and increase in PEG 6000 reduced germination and seedling growth beyond 60 g/L. Key words: Germination, maize, seedling growth, stress, tolerance

SMALLHOLDER FARMERS’ PERCEPTIONS OF DROUGHT RISK AND ADOPTION OF MODERN MAIZE IN SOUTHERN MALAWI

SUMMARYModern maize varieties have been bred for drought tolerance and early maturity, to assist farmers in avoiding or escaping the effects of moisture stress in drought-prone areas. This study evaluates the prospects for widespread adoption of these modern maize varieties as a climate change adaptation strategy for smallholder farmers. Data are from a detailed household survey completed in four rural villages in Southern Malawi between May and July 2010. The empirical analysis involves estimation of an ordered logit regression model because the dependent variable is categorical, with one category for nonadoption (has never grown modern maize varieties) and three categories for the duration of growing a modern maize variety among adopters (this year only, 2 to 5 years and 6 years or more). The empirical findings indicate a positive association between a farmer's perception of drought risk and the adoption and continued use of modern maize. Regression results also show that farmers that value the traits of early maturity and drought tolerance are more likely to adopt modern maize varieties. There is evidence of some disadoption among farmers dissatisfied with maize genotype performance, in terms of poor storability and yield under drought conditions. Finally, the study highlights the urgent need for maize breeders interested in sustained use of modern varieties to simultaneously address robust drought tolerance, early maturity and storability. This underscores the importance of cognizance of local farmer preferences in crop breeding efforts.

EFFECTS OF SHADING AND MOISTURE STRESS ON YIELD AND OIL QUALITY OF HYDROPONICALLY GROWN ROSE GERANIUM

Rose geranium oil is used as a flavouring agent in many major food items and alcoholic and soft drinks. Relatively high radiation levels occur in South Africa during summer months and some hydroponically grown crops may need shading for optimum production. This study was conducted during spring and summer to evaluate the effects of shading and moisture stress on growth, oil yield and oil quality of rose geranium. A split plot experimental layout was assigned in randomized complete block design. Treatment with 0, 20, 40, 60 and 80% shading were allocated to the main plots. Subplots were exposed to two moisture stress levels of 0 and -0.15 MPa of osmotic pressure. The results show that rose geranium performs well when grown at a shade netting of 40%, where the number of branches, foliar fresh and dry mass, branch:height ratio as well as the oil yield peaked. Proline content was significantly higher at a low level of shading, where high levels of radiation were found and where moisture stress was applied. However, moisture stress did not affect any of the quality parameters measured for rose geranium oil. Most of the chemical substances produced at 40% shading level were of good oil quality. This study shows that 40% shade should be used to grow rose geranium in summer.

Evaluation of genotypic response of kabuli chickpea (cicer arietinum l.) cultivars to irrigation regimes in northwest of iran

Abstract Water deficiency is commonly the most important yield -restraining factor in semi-arid and Mediterranean environments. Chickpea (Cicer arietinum L.), which is one the main legume crops of the region, often experiences terminal drought. To investigate the response of chickpea genotypes to different irrigation levels, experiments were conducted in Maragheh, Northwest Iran. Three levels of irrigation including zero (rain-fed condition), full irrigation (enough water to fill the root zone profile) and two supplement irrigations (SIs) during flowering and grain filling stages were evaluated over 2013 growing season. Results revealed that plant height, canopy spread, primary and secondary branches, chlorophyll content, day to maturity, grain yield and yield components were significantly affected by irrigation regimes. However, there was no statistically significant difference between full irrigation and SI for number of pods per plant, number of seeds per pod, 100-grain weight, grain yield per unit area and grain filling rate. The seed yield of the genotypes when grown under the full irrigation condition increased at a rate of 58% over those in rain-fed condition. Investigation of grain yield and drought resistance indices revealed that FLIP 98-106C and Arman can be selected as the best tolerant genotypes to rain-fed condition. In general, under semi-arid conditions and where some limited water resources are available, SI could be an efficient management practice for alleviating the unfavourable effects of soil moisture stress on the yield of rain-fed chickpea during crucial reproductive growth stages.

Integrating phylogenetic community structure with species distribution models: an example with plants of rock barrens

Approaches using phylogenetic pattern in ecological communities to deduce processes of community assembly have been criticised as disconnected from foundations in ecological mechanism, especially with respect to lack of data about abiotic and biotic niches. These criticisms can be addressed with analyses of organismal traits that underlie environmental filtering, competitive exclusion, and other candidate processes; however, the difficulty of assembling large trait databases means that such studies remain uncommon. We suggest a synthesis of phylogenetic community structure analysis and species distribution modeling that we believe can allow inference about community processes without prohibitive data requirements. We illustrate this method for angiosperm communities of rock barrens in eastern Canada. First, we analyzed phylogenetic community structure of four rock‐barren sites at three nested spatial scales (quadrat to region). For the nine most common species in our barrens, we used regional occurrence records to build species distribution models identifying environmental drivers of the nine species’ distributions. Coefficients of these models represent implicit trait data that summarize each species’ response to the environmental drivers in the model. We then tested for phylogenetic signal in these traits, to ask whether ecological forces acting on them could be generating phylogenetic community structure. We found strong phylogenetic clustering at the quadrat level, while patterns at larger scales were complex. Our distribution model suggested drought stress as the dominant driver for distributions of all the species, consistent with local correlations with soil depth, and the species’ responses to drought showed strong phylogenetic signal. The convergence of results from phylogenetic community structure and species distribution modeling suggests that barren communities are structured at the quadrat level by environmental filtering effects of moisture stress, to which species have phylogenetically patterned responses.

Growth-Climate Relationships ofPinus strobusIn the Floodway Versus Terrace Forest Along the Banks of the Red Cedar River, Michigan

We examined the effects of climate (i.e. temperature, precipitation, moisture index, river discharge) on the radial growth of eastern white pine (Pinus strobus) in two contrasting microhabitats (floodway versus terrace) in relation to an elevational and moisture gradient along the banks of the Red Cedar River, Michigan. We hypothesized that trees growing on the terrace sites would have a greater sensitivity to climatic factors than trees growing in the floodway. Increment cores were sampled and crossdated from dominant and co-dominant trees in the floodway and terrace sites and standardized growth chronologies were developed. Mean sensitivity, standard deviation, percentage of absent rings, and intertree correlation were generally greater for eastern white pine on the terrace compared to the floodway forests. Dendroclimatic relationships were examined with bootstrapped correlation analysis, which indicated that radial growth of eastern white pine in both floodway and terrace sites was negatively associated with summer temperature (i.e. June and July) of the current growing season. Radial growth in both floodway and terrace sites were positively related to current May precipitation, moisture index, and river discharge. Dendroclimatic response of eastern white pine in floodway and terrace sites differed in that the effect of summer moisture stress was more persistent in the terrace sites into later summer (i.e. current July ) whereas floodway sites showed a negative response to prior-year May precipitation and moisture index. Although precipitation and hydrological conditions of the river were generally favorable during the summer months, which appeared to have promoted soil moisture recharge, flooding in early winter (i.e. prior November) had a negative impact on growth in both microhabitats. The effect of winter river discharge was significantly negative in January (t) in the floodway sites compared to the terrace sites.

Needle parameter variation of mature black spruce displaying genetic × soil moisture interaction in growth

To examine soil moisture stress, light, and genetic effects on individual needle parameters and investigate total needle contribution to productivity, indi- vidual and total needle parameter variation were quantified in 32-year-old black spruce from five crown positions from four full-sib families studied previously for drought toler- ance and differential productivity on a dry and a wet site. The wet site had greater average needle length (NL), spe- cific needle area (SNA), and needle N concentration (NN) than the dry site. Site differences in NN were most likely driven by soil moisture stress impairing N uptake as soil N was equal at both sites. Drought-tolerant families had greater average needle area (NA), but also greater needle dry mass (NDM), than drought-intolerant families. From the top to bottom crown position, needle parameters showing a linear or near linear increase were NL, SNA, and NN; needle parameters showing a linear decrease were NW, NA, NDM and C:N ratio. For total tree needle area, the wet and dry sites had 18.7 and 16.0 m 2 tree -1 (leaf area index (LAI) 5.6 and 4.8), respectively, whereas total needle C mass was not significantly different between sites. Drought-tolerant and intolerant families had a total NA of 18.8 and16.0 m 2 tree -1 , respectively. However, the greater total NA of drought-tolerant families was driven by one family. Thus, the role of total foliage area at these high LAI values in genetic differences in productivity is inconsistent and most likely low. Therefore, based on a previous 3-year campaign of gas exchange measurements and confirmed independently with carbon isotope analyses, the rate of net photosynthesis is a more important component of site and genetic growth differential in mature black spruce than total needle area.