Development of an assay to evaluate differences in germination rate among chickpea genotypes under limited water content

2012 ◽  
Vol 39 (1) ◽  
pp. 60 ◽  
Author(s):  
Saeedreza Vessal ◽  
Jairo A. Palta ◽  
Craig A. Atkins ◽  
Kadambot H. M. Siddique
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Seedling Growth ◽  
Germination Rate ◽  
Water Levels ◽  
Assay System ◽  
Superior Performance ◽  
Genotypic Differences ◽  
Early Stages

An assay system that provides rapid and reproducible germination under low soil water content (<10% water holding capacity (WHC)) was developed and used to compare how chickpea (Cicer arietinum L.) genotypes complete germination, without the technical difficulties of accurately controlling water levels. The system consisted of small plastic containers (50 mm × 50 mm × 60 mm) filled with river sand and tightly closed (but not sealed) to minimise water loss and maintain constant soil water content during germination. Seed size influenced germination performance at low WHC. Small seeds within a single genotype germinated successfully and entered into the early stages of seedling growth, but germination of large seeds was inhibited, failing to germinate at 5% WHC. Small seeds were more efficient in remobilising seed reserves to seedling tissues than larger seeds. Under optimal WHC, the germination rate and subsequent radicle growth was similar among genotypes but at low WHC, there was variation despite seeds being of comparable size and imbibing equally. This suggests that the physiological threshold of threshold water potential for initiation of germination reflects genotypic differences. The assay system provides a suitable experimental tool to examine gene expression in contrasting genotypes during germination and early stages of seedling growth with a view to identifying the genes involved in superior performance under water limited field conditions.

Effect of soil water content and temperature on dormancy breaking and germination of three weeds

Weed Science ◽  
1997 ◽  
Vol 45 (6) ◽  
pp. 791-797 ◽  
Author(s):  
Maria A. Martinez-Ghersa ◽  
Emilio H. Satorre ◽  
Claudio M. Ghersa
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Seed Dormancy ◽  
Seedling Establishment ◽  
Germination Rate ◽  
High Rate ◽  
Dormancy Breaking ◽  
Species Response ◽  
Redroot Pigweed

In laboratory experiments, we studied barnyardgrass, common lambsquarters, and redroot pigweed seed dormancy release by alternating temperatures under different soil water regimes, to determine whether that response serves as a mechanism for assuring seedling establishment. Alternating temperatures were important in breaking seed dormancy in the three weeds, but the species' response to alternating temperatures differed with soil water content. For redroot pigweed and newly dispersed seeds of barnyardgrass, dormancy breaking by alternating temperatures occurred only when soil water content was high enough for germination. Moreover, adverse incubation conditions (constant temperature and low water content) induced secondary dormancy in these seeds. Seventy percent of seeds incubated in open boxes emerged before the soil reached wilting point, when seeds were incubated at temperatures high enough for a high germination rate. A dormancy breaking mechanism that triggers a high rate of germination may be important in assuring success of seedling establishment where rainfall patterns result in wetting and drying cycles of the soil, especially in soil types that lose water rapidly from the surface layers.

scholarly journals A new framework for modelling seed germination and seedling tillering of winter wheat in the field

2021 ◽  
Author(s):  
Jinping Chen ◽  
Peter Whalley ◽  
Yang Gao ◽  
xiaoxian zhang ◽  
Malcolm J. Hawkesford ◽  
...  
Keyword(s):  
Seed Germination ◽  
Winter Wheat ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Genetic Heterogeneity ◽  
Germination Rate ◽  
Environmental Cues ◽  
Metabolic Reactions ◽  
New Framework

Seed germination is regulated by multiple environmental cues and understanding their relationships is critical to planning seed drilling and subsequent seedling management. We develop a new framework by viewing the metabolic reactions associated with seed germination as a moving event in a physiological dimension to simulate seed germination. Fluctuations in environmental cues and genetic heterogeneity of seed lot make the metabolic reactions in each seed uncertain, and we use an average germination rate to describe the average metabolic reactions and a dispersion coefficient to describe the genetic heterogeneity. We apply the model to winter wheat seeds drilled at different dates in plots under different soil water contents and prove that the model accurately reproduces the time course of germination in all treatments. We found the average germination rate increases nonlinearly with temperature in the base-suboptimal temperature range, and there is an optimal soil water content where the germination rate peaks due to soil anaerobicity. Our model can be fitted to field data using temperature and soil water content to describe the trade-off impact of soil water on soil anaerobicity and imbibition, whereas the difficulty of obtaining accurate water potential and oxygen measurements makes this difficult with the hydrothermal time models.

scholarly journals Morphophysiological and phytochemical responses of fenugreek to plant growth promoting rhizobacteria (PGPR) under different soil water levels

2018 ◽  
Vol 30 (2) ◽  
pp. 215-228
Author(s):  
Ali Sharghi ◽  
Hassanali Naghdi Badi ◽  
Sahebali Bolandnazar ◽  
Ali Mehrafarin ◽  
Mohammad Reza Sarikhani
Keyword(s):  
Plant Growth ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Plant Growth Promoting Rhizobacteria ◽  
Water Levels ◽  
Flowering Stage ◽  
Positive Effects ◽  
Plant Growth Promoting ◽  
Growth Promoting

Abstract Fenugreek (Trigonella foenum-graecum L.) is a valuable medicinal plant, which is widely distributed throughout the world. It has been known that plant growth promoting rhizobacteria (PGPR) have positive effects on the quality and quantity of medicinal plants under different soil water levels. For this reason, a factorial experiment was conducted on the basis of a randomized complete block design (RCBD) to evaluate PGPR effects on the morphophysiological and phytochemical traits of fenugreek under different soil water levels. This study was conducted in two separate experiments: after the six-leaf stage and after the flowering stage. In the experiments, the treatments were plant growth promoting rhizobacteria (PGPR) including the control, Sinorhizobium meliloti, Pseudomonas fluorescens, a combination of S. meliloti and P. fluorescens, and different soil water levels (i.e. 100, 80, 60 and 40% of field capacity (FC) in three replications. The results showed that the highest seed weight per plant was obtained by inoculation with the S. meliloti and P. fluorescens combination at 100% FC after the two developmental stages. The maximum concentrations of nicotinic acid and trigonelline were observed for the combination of S. meliloti and P. fluorescens at the soil water content of 40% FC after the six-leaf stage and for S. meliloti at the soil water content of 40% FC after the flowering stage. The correlation and stepwise regression analyses showed positive effects of PGPR application on the morphophysiological and phytochemical traits of fenugreek plants under different soil water levels.

Near-infrared spectroscopy for soil water determination in small soil volumes

2004 ◽  
Vol 84 (3) ◽  
pp. 333-338 ◽  
Author(s):  
P. R. Bullock ◽  
X. Li ◽  
L. Leonardi
Keyword(s):  
Infrared Spectroscopy ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Water Levels ◽  
Least Squares Regression ◽  
Volumetric Soil Water Content ◽  
Volumetric Soil Water

Critical soil water levels for soil microscale processes are difficult to determine because of variability in large soil volumes and lack of techniques for logging soil water contents in small soil volumes. This study tested nearinfrared (NIR) spectroscopy for soil water content determination. Five soil horizons with a range in soil texture, soil organic carbon, carbonates, pH and horizon depth, were tested at air-dry, field capacity and 0.1 MPa tension water content. Volumetric soil water content, determined using the standard method of oven-drying and soil bulk density, was compared to NIR absorbance in various combinations and wavelengths. The NIR spectra obtained with the probe in direct contact with the soil gave better results than when the probe was separated from the soil with a glass slide. The most reliable validation results were obtained using a multivariate partial least squares regression of the full spectrum with an r2 of 0.95 and RMSE of prediction of 6.4%. Smoothing and derivatives of the spectra did not improve the validation results. The relationships for absorbance at single wavelength segments, ratios, differences and area under the curve around the 1940 nm peak were good (r2 values near 0.85 ) but poorer than the results using the full spectra. The high correlation coefficients obtained with the wide variety of soils utilized in this study suggest that NIR absorbance is a practical method for determining volumetric soil water content for small soil volumes. Key words: Near-infrared spectroscopy, soil water, Near-infrared absorbance

scholarly journals A Laboratory Study on Non-Invasive Soil Water Content Estimation Using Capacitive Based Sensors

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 651 ◽  
Author(s):  
Amir Orangi ◽  
Guillermo A. Narsilio ◽  
Dongryeol Ryu
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Low Cost ◽  
Measurement Techniques ◽  
Soil Surface ◽  
Superior Performance ◽  
Spatiotemporal Resolution ◽  
Non Invasive ◽  
Soil Surface Roughness

Soil water content is an important parameter in many engineering, agricultural and environmental applications. In practice, there exists a need to measure this parameter rather frequently in both time and space. However, common measurement techniques are typically invasive, time-consuming and labour-intensive, or rely on potentially risky (although highly regulated) nuclear-based methods, making frequent measurements of soil water content impractical. Here we investigate in the laboratory the effectiveness of four new low-cost non-invasive sensors to estimate the soil water content of a range of soil types. While the results of each of the four sensors are promising, one of the sensors, herein called the “AOGAN” sensor, exhibits superior performance, as it was designed based on combining the best geometrical and electronic features of the other three sensors. The performance of the sensors is, however, influenced by the quality of the sensor-soil coupling and the soil surface roughness. Accuracy was found to be within 5% of volumetric water content, considered sufficient to enable higher spatiotemporal resolution contrast for mapping of soil water content.

scholarly journals Influence of soil water content and soil amendments on trace metal release and seedling growth in serpentine soil

2019 ◽  
Vol 19 (12) ◽  
pp. 3908-3921 ◽  
Author(s):  
Viraj Gunarathne ◽  
Nishanta Rajakaruna ◽  
Udaya Gunarathne ◽  
Jayanta Kumar Biswas ◽  
Zach A. Raposo ◽  
...  
Keyword(s):  
Trace Metal ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Seedling Growth ◽  
Soil Amendments ◽  
Serpentine Soil ◽  
Metal Release

scholarly journals Soil water content and emergence time control seedling establishment in three co-occurring Mediterranean oak species

2008 ◽  
Vol 38 (9) ◽  
pp. 2382-2393 ◽  
Author(s):  
Itziar R. Urbieta ◽  
Ignacio M. Pérez-Ramos ◽  
Miguel A. Zavala ◽  
Teodoro Marañón ◽  
Richard K. Kobe
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Seed Mass ◽  
Water Levels ◽  
Summer Drought ◽  
Mediterranean Forests ◽  
Emergence Time

Tree species can differ in their responses to resource availability during the critical phase of establishment, which could influence forest dynamics. In Mediterranean forests, most of the attention has focused on the effects of shade and summer drought on seedling survival, but little is known about the effect of autumn to spring rains on earlier stages of recruitment. A sowing experiment was set up along natural light and water gradients with three co-occurring oak species ( Quercus suber L. (cork oak), Quercus canariensis Willd. (Algerian oak), and Quercus pyrenaica Willd. (Pyrenean oak)) that show limited natural regeneration in southern Spain. Recruitment stages were monitored for 1 year. Models of seed germination, seedling emergence, and seedling survival as well as of overall recruitment patterns were developed as functions of light, soil moisture, and soil compaction. The influence of intraspecific variation in seed mass and emergence time were also tested. Excess soil water levels during the winter reduced germination and emergence and lengthened time to emergence (in waterlogged open areas), which in turn decreased seedling survival during the dry season. Seedlings from larger seeds were more likely to germinate and emerge. The results suggest that temporal and spatial variability of soil water content, mediated by emergence time and seed size, play a crucial role in the regeneration dynamics of Mediterranean oak forests.

Soil water content as a key factor determining the source of nitrogen (NH4+ or NO3−) absorbed by Douglas-fir (Pseudotsugamenziesii) and the pattern of rhizosphere pH along its roots

1991 ◽  
Vol 21 (5) ◽  
pp. 616-625 ◽  
Author(s):  
Arjan J. Gijsman
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Levels ◽  
Ammonium Uptake ◽  
Root Tip ◽  
Gradual Transition ◽  
Rhizosphere Ph ◽  
Root Zones ◽  
Dry Soil

Pseudotsugamenziesii (Mirb.) Franco was grown on an acid sandy soil [Formula: see text], fertilized with ammonium nitrate as the nitrogen source (50 and 150 kg N•ha−1), and maintained at two soil water levels. At both nitrogen levels, ammonium uptake was much higher in the wet soil than in the dry soil, whereas nitrate uptake was not affected by soil water content. From calculation of the nitrogen supply at the root surface, it was concluded that P. menziesii preferentially took up ammonium. Under dry soil conditions, movement of ammonium in the soil was impeded, so that the ammonium preference could not manifest itself; thus a large part of the nitrogen absorbed was in the nitrate form. Proton excretion per unit organic nitrogen formed was greater in the wet soil than in the dry soil owing to a larger ammonium contribution to total nitrogen uptake. In all treatments, the rhizosphere at the root tip was more alkaline than the bulk soil, whereas along the older root zones, acidification of the rhizosphere occurred. The strongest alkalization at the root tip occurred in the dry soil. Analysis of the rhizosphere pH pattern with a simulation model on proton transport in the soil showed that the results could only be explained by a gradual transition from OH− excretion at the root tip to H+ excretion along the older root zones. Soil water content was an important factor in determining rhizosphere pH. By extrapolating the results to forest conditions, it was determined that rhizosphere acidification may occur when the nitrification rate is low and the soil is not too dry.

SOIL WATER CONTENT AFFECTS THE AVAILABILITY OF PHOSPHATE

1985 ◽  
pp. 185-189
Author(s):  
M.C.H.Mouat Pieter Nes
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Solution ◽  
Equivalent Reduction

Reduction in water content of a soil increased the concentration of ammonium and nitrate in solution, but had no effect on the concentration of phosphate. The corresponding reduction in the quantity of phosphate in solution caused an equivalent reduction in the response of ryegrass to applied phosphate. Keywords: soil solution, soil water content, phosphate, ryegrass, nutrition.

Effect of inter-row cultivation on soil carbon dioxide emission in a peach plantation

2010 ◽  
Vol 59 (1) ◽  
pp. 157-164 ◽  
Author(s):  
E. Tóth ◽  
Cs. Farkas
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Carbon Dioxide Emission ◽  
Nutrient Content ◽  
Soil Disturbance ◽  
Biological Properties ◽  
Soil Tillage ◽  
Favourable Effect ◽  
Volumetric Soil Water Content

Soil biological properties and CO2emission were compared in undisturbed grass and regularly disked rows of a peach plantation. Higher nutrient content and biological activity were found in the undisturbed, grass-covered rows. Significantly higher CO2fluxes were measured in this treatment at almost all the measurement times, in all the soil water content ranges, except the one in which the volumetric soil water content was higher than 45%. The obtained results indicated that in addition to the favourable effect of soil tillage on soil aeration, regular soil disturbance reduces soil microbial activity and soil CO2emission.

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