Hydration Treatments Research Articles

Time Course Study of Ethanol Production by Corn and Soybean to Optimize the Use of ANA Ethanol Index as an Accurate Seed Quality Test

The ratio of ethanol production by seeds under anaerobic and aerobic conditions (ANA ethanol index) was shown to be a good indicator of seed quality in our previous studies. A time course study of ethanol production by corn (Zea mays L.) and soybean (Glycine max L. Merill) was conducted to identify the optimum hydration time for calculation of the ANA ethanol index. In addition, microbial contamination was studied both from seeds after aging and after hydration. Seeds of corn and soybean were aged at 75% relative humidity and 45 C for 0 to 32 days to obtain different seed quality samples. Ethanol production increased with hydration time (0 to 24 hours), and production was greater for soybean than for corn. Ethanol production decreased with aging under anaerobic conditions, while a biphasic pattern was measured with aging under aerobic conditions after a 24 hour hydration period. The ANA ethanol index changed with both hydration time and seed quality. The optimal hydration time was 24 hours to rank seed quality for both species. Moreover, ANA ethanol index was positively related to germination rate for corn and soybean. Microbial contamination was minimal after aging or had negligible effects on ethanol production under aerobic and anaerobic hydration treatments.

The influence of aerated hydration seed treatment on seed longevity as assessed by the viability equations.

Aerated hydration (AH) treatments of cauliflower seeds for 12 h (12AH) and 28 h (28AH) at 20 degrees C resulted in improved or reduced storage potential of low or high vigour seeds, respectively. Seeds were stored at their initial seed moisture content (mean 5.5% mc) or at 12% mc at 10 degrees C for 12 months and at 20 degrees C for 4 months. The improved longevity of low vigour seeds was associated with increased K(i) (initial seed viability) and a reduced rate of deterioration (1/sigma) whereas the K(i) of high vigour seeds fell after 28AH and the rate of deterioration increased such that the time to lose one probit of viability decreased from 28.7 to 5.3 months at 10 degrees C and from 10.4 to 1.2 months at 20 degrees C. The improved K(i) of low vigour seeds could be explained by the reduction in the extent of deterioration after AH, as indicated by the increase in germination after cotrolled deterioration (CD), and the possible activation of metabolic repair during treatment. In contrast the reduced germination after CD of AH-treated high vigour seeds was indicative of deterioration as a result of treatment. Both high and low vigour seeds contained constitutive levels of ss-tubulin which increased during AH treatment, the increase being greater in high vigour seeds. High vigour seeds also showed an increase in the proportion of nuclear DNA present as 4C DNA, from 3% (untreated seeds) to 26% (28AH), indicative of germination advancement from the G(1) to G(2) phase of the cell cycle during treatment. This higher proportion of 4C DNA is correlated with the increased sensitivity of seeds to drying and/or storage after AH, leading to their reduced K(i) and storage potential. In contrast, there was little change in %4C in low vigour seeds. Priming in polyethylene glycol (PEG, -1.0 MPa) for 5 d or 13 d also improved the longevity of low vigour seeds stored at their initial and 12% mc at 10 degrees C for 8 months, as reflected in their laboratory and CD germination. In this case, however, the improved longevity of the low vigour seeds following 13 d priming was associated with an increase in 4C DNA from 4% (dry control) to 56% after treatment. The germination of both untreated and primed high vigour seeds remained high throughout the storage period. Increases in the rate of germination (decreased mean germination time) observed after all AH and PEG treatments were not consistently associated with an increase in the proportion of nuclei containing 4C DNA.

Dehardening of Annual Bluegrass and Creeping Bentgrass during Late Winter and Early Spring

Changes in cold hardiness levels of annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis palustris Huds.) were monitored under field conditions during the dehardening period of late winter and early spring. During the course of two spring periods the cold hardiness levels of the two species were monitored in conjunction with the following hydration treatments: snow cover maintained to prolong dormancy, snow removal in March, and hydration of crown tissues in combination with snow removal. Cold hardiness levels, percent crown moisture, and soil temperatures were monitored throughout this period. Cold hardiness levels were significantly influenced by year, species, hydration treatment, and a number of interactions of these factors. Generally, plants dehardened 2 wk earlier in 1997 than in 1996. On 1 April, creeping bentgrass had cold hardiness levels averaging −20°C compared to −13°C for annual bluegrass. By 15 April, creeping bentgrass plants had lost their cold hardiness advantage. Increased soil temperature was the greatest contributor to the loss of hardiness in the spring. An increase in crown moisture of 4% for annual bluegrass and 6% for creeping bentgrass occurred during the period from 25 March to 22 April. Maintaining a snow cover on plots delayed the loss of cold hardiness by 6 to 9 d in 1996 but had no effect in 1997. Maintaining a snow cover also delayed the increase in crown hydration by a week. Plants were able to partially regain cold hardiness when soil temperatures dropped.

Improvement of Brown Bread Quality by Prehydration Treatment and Cultivar Selection of Bran

ABSTRACTDifferent bran pretreatments and bran cultivars were investigated with the aim of alleviating the adverse effects caused by bran addition in brown (fiber‐rich) bread. Three different bran treatments: hydration, wet heat, and wet oxidation, all hydrate bran before its addition to other breadmaking ingredients. Four different bran cultivars were investigated. All treatments improved brown bread quality significantly, resulting in larger, softer loafs. All treatments resulted in an increase in the water absorption of brown bread doughs and a decrease in potentially oxidizable substances (POS) in brans. It is suggested that prehydration treatment activates bran lipoxy‐Different bran pretreatments and bran cultivars were investigated with the aim of alleviating the adverse effects caused by bran addition in brown (fiber‐rich) bread. Three different bran treatments: hydration, wet heat, and wet oxidation, all hydrate bran before its addition to other breadmaking ingredients. Four different bran cultivars were investigated. All treatments improved brown bread quality significantly, resulting in larger, softer loafs. All treatments resulted in an increase in the water absorption of brown bread doughs and a decrease in potentially oxidizable substances (POS) in brans. It is suggested that prehydration treatment activates bran lipoxygenase which oxidizes POS in bran, reducing bran's contribution to brown bread dough. A further reduction of these substances is caused by a washout effect of the treatments. On average across all bran cultivars, the hydration and wet oxidation treatments improved brown bread quality significantly more than the wet heat treatment, which also reduced the bran POS significantly less than the other treatments, probably due to its rapid inactivation of lipoxygenase. The bran cultivars differed significantly in their effects on brown bread quality, suggesting that bran selection according to cultivar should be considered.

Seed enhancements

AbstractSeed enhancements may be defined as post-harvest treatments that improve germination or seedling growth, or facilitate the delivery of seeds and other materials required at the time of sowing. This definition includes three general areas of enhancements: pre-sowing hydration treatments (priming), coating technologies and seed conditioning. Pre-sowing hydration treatments include non-controlled water uptake systems (methods in which water is freely available and not restricted by the environment) and controlled systems (methods that regulate seed moisture content preventing the completion of germination). Three techniques are used for controlled water uptake: priming with solutions or with solid particulate systems or by controlled hydration with water. These priming techniques will be discussed in this paper with reference to methodology, protocol optimization, drying and storage. Coating technologies include pelleting and film coating, and coatings may serve as delivery systems. Seed conditioning equipment upgrades seed quality by physical criteria. Integration of these methods can be performed, and a system is described to upgrade seed quality inBrassicathat combines hydration, coating and conditioning. Upgrading is achieved by detecting sinapine leakage from nonviable seeds in a coating material surrounding the seeds. Seed-coat permeability directly influences leakage rate, and seeds of many species have a semipermeable layer. The semipermeable layer restricts solute diffusion through the seed coat, while water movement is not impeded. Opportunities for future seed enhancement research and development are highlighted.

Hydration−Dehydration-Induced Reversible Ordering−Disordering Transition of the Molecular Arrangement on the Surface of KCP(Br) Single Crystals

Molecular-resolution images by atomic force microscopy (AFM) revealed a reversible ordering−disordering transition of molecular arrangements on the (010) face of a single crystal of potassium tetracyanoplatinate bromide (KCP(Br)) during dehydration and hydration treatments. The intracolumnar Pt−Pt distance along the c-axis in the dehydrated crystal lengthens by a factor of 30% with considerable disordering, and the rehydrated crystal shows well-ordered arrangement like the as-grown crystal, while the intercolumnar structure along the orthogonal direction is not varied. Large-scale AFM images showed that the monolayer terraces reversibly slide in the c-axis direction during the dehydration−hydration treatments, reflecting the molecular dislocation along the c-axis. This surface structural change is quite consistent with well-known dehydration effects in KCP(Br) crystals, i.e., the lattice disordering and the decreasing conductivity.

Interaction of hydration and subfornical organ lesions in sodium-depletion induced salt appetite.

The authors tested whether the level of hydration after furosemide diuresis and 22 hr of sodium depletion affects the amount of water or 0.3 M NaCl solution consumed by rats with intact brains or with lesions of the subfornical organ (SFO). Rats received 2 (underhydrated) or 10 (euhydrated) ml/kg water by gavage as the only fluid input 2, 4, and 20 hr after 10 mg/kg furosemide. These hydration treatments had little or no effect on the amount of saline consumed in 2 hr by intact rats. SFO lesions reduced water intake regardless of hydration condition. Euhydrated, SFO-lesioned rats drank a normal amount of saline, but underhydrated, lesioned rats drank less saline than any other group. Thus, euhydration may facilitate salt appetite in SFO-lesioned rats, and the deficits in salt appetite noted in SFO-lesioned rats may result from deficits in water ingestion rather than from a destruction of angiotensin II receptor sites that directly provoke salt appetite.

Effects of pre-storage hydration treatments on germination performance, moisture content, DNA synthesis and controlled deterioration tolerance of tomato (Lycopersicon esculentum Mill.) seeds

AbstractStorage of tomato seeds under deteriorating conditions reduced the rate of germination, the uniformity of germination, total germination and the proportion of normal seedlings. Pre-storage humidification and hydropriming of seeds resulted in a significant increase in resistance to deterioration. In contrast, osmoprimed seeds were more deterioration sensitive. Humidification or hydropriming for one day did not allow nuclei to enter the S phase of the cell cycle. Osmopriming strongly increased the percentage of nuclei with replicated DNA in the embryonic root tip, indicating initiation of the cell cycle and progression towards the G2 phase. The interaction between the prestorage treatments, cell cycle progression and deterioration resistance, is discussed. Based on the changes in moisture content equilibrium and cell cycle activity it is hypothesized that the beneficial effects of pre-storage humidification and hydropriming were related to metabolic activities induced by the partial hydration and that the adverse effects of osmopriming were caused by a decrease in DNA repair activity due to progression in the cell cycle.

Hydration effect on seedling emergence strength of watermelon seeds differing in ploidy

Although hydration may improve the germination ability of polyploid watermelon seed, the impact of this factor on seedling emergence force has not been critically examined. Three watermelon seedlots (4.7% seed moisture level on fresh weight basis) differing in ploidy were used to study the influence of hydration on seedling emergence performance. Hydration was achieved by mixing the seeds with moist vermiculite No. 3 at 25°C for 24 h. The partially hydrated seeds were air-dried at 25°C for 36 h to 4.7% moisture level. Significant differences existed among the seedlots and between hydration treatments for emergence performance, moisture absorption and emergence force exerted by seedlings. Triploid seeds had a lower emergence percentage than diploid seeds, possibly due in part to their higher seed coat splitting strength and weak seedling emergence strength. Hydrating the seeds in moist vermiculite is an effective means of improving seedling emergence. The improved emergence percentage of vermiculite-hydrated seeds might be attributable to the hydration-strengthened seedling emergence strength.

Effect of hydration treatments on laryngeal nodules and polyps and related voice measures

In this study, a double-blind, placebo-controlled approach was used in assessing the effectiveness of hydration treatments in the clinical management of selected voice disorders. Six adult female patients with laryngeal nodules or polyps each received 5 consecutive days of hydration treatment and 5 consecutive days of placebo/control treatment. The combined results indicated improvements in voice and in laryngeal appearance following both placebo/control and hydration treatments as compared with baseline. However, the greatest improvements were obtained following the hydration treatment. Although caution about generalization of the effects to the typical clinical situation is emphasized, the study provides preliminary evidence of a therapeutic benefit from hydration treatments in patients with nodules or polyps. Based on previous theoretical work, hydration effects may be related to reductions in the viscosity of vocal fold tissue, although other explanations are also possible.

Effects of temperature of pre-sowing hydration treatment and subsequent drying rates on the germination performance of celery seed

Abstract There is considerable potential for the improvement of the slow and irregular germination of celery seeds (Apiurn graveolens L.) by pre-sowing hydration treatments, but poor germination performance as a result of drying seeds after treatment is a recurrent problem. Over the temperature range 5–20°C the onset of seed germination is determined by a thermal time relationship, but a pre-sowing treatment temperature of 15°C was identified as the most effective for the two celery cultivars—‘Tall Utah 52–70’ and ‘Green Giant Hybrid’—when the seeds were only surface-dried before sowing. However, conventional air-drying of treated seeds at 20°C caused severe delays in germination and decreased uniformity. Higher treatment temperatures reduced the adverse effect of drying on the seeds but resulted in little or no germination advantage because of thermodormancy, which was particularly evident at 25°C. Deleterious effects of drying-back were avoided, and in some instances further germination enhancement gain...

Hydration‐Dehydration Treatments to Protect or Repair Stored ‘Karamu’ Wheat Seeds

Although presowing hydration treatments are known to be capable of improving the germination performance of wheat seeds, no comprehensive information is available, especially with regard to the effectiveness of such treatments on seeds subjected to deterioration under different conditions. This study reports an attempt to understand the responses of a single high‐quality seed lot of wheat (Triticum aestivum L.) to two different storage regimes (100% relative humidity, 40 °C for up to 6 d or at a constant seed moisture content of 0.15 g H2O g−1 fresh weight at 35 °C for up to 50 d). At the same time the relative abilities of three presowing hydration‐dehydration treatments to protect or repair the deteriorating seeds were compared. Although losses of viability and increases in radicle emergence rates followed a similar pattern for both regimes, assessments of electrical conductivity of seed leachate and seedling growth indicated that the mechanisms of deterioration varied under the two aging conditions. A 2‐h prestorage hydration treatment at 25 °C followed by drying allowed maintenance of germinability in storage, but only had marginal effects when applied after aging. Longer hydration treatments (24 h at 15 °C in water or 20 h at 20 °C in −0.37 MPa polyethylene glycol solution) applied after storage were effective at restoring germination rates of seeds that remained viable. if applied before storage, however, these two treatments severely increased the seeds' susceptibility to deterioration. These results demonstrate that (i) not all aspects of deterioration in wheat seeds are irreversible, and (ii) losses of seed vigor and viability are not necessarily features of the same continuum of deteriorative metabolism. Such combinations of treatments and storage conditions should provide useful systems for the systematic study of deteriorative metabolism in aging wheat seeds.

The Influence of Pre and Post-storage Hydration Treatments on Chromosomal Aberrations, Seedling Abnormalities, and Viability of Lettuce Seeds

A 2 h soaking treatment in distilled water, or in aqueous solutions of cysteine, potassium iodide, or sodium thiosulphate, had no significant effect (P > 0.25) on the subsequent longevity of lettuce seeds (Lactuca sativa L.) in two different storage environments. Neither did these treatments influence relations between loss in germination and the frequency of chromosomal aberrations observed during first mitoses after storage. In contrast partial hydration of lettuce seeds after storage by exposure to moist air (humidification) or to an osmoticum (priming) reversed some of the damage which resulted from ageing. Most of the benefits occurred during the first 3 d of humidification during which seed moisture content rose to 34 per cent, or during the first 7 d of priming when seed moisture content increased to 44 per cent. Both post-storage hydration treatments reduced the frequency of chromosomal aberrations, increased the rate of root growth, and decreased the frequency of morphologically abnormal seedlings. Either treatment could be of practical use, but it is suggested that humidification is more convenient. Consideration should be given to adopting a humidification treatment as standard practice following long-term seed storage for genetic conservation

Seed Hydration Treatments For Improved Sweet Corn Germination and Stand Establishment

Abstract This research examines the potential of seed hydration for improving sweet corn (Zea mays L.) seed performance, especially for plantings in cool (10°–15°C) soils. In addition to the effect of hydration treatments, the influence of seed quality and cultivar was evaluated using electrolyte leakage tests and seedling growth cold tests. Seed hydration treatments included seed hardening (a wetting/drying cycle), seed moisturizing (placing seed in moist vermiculite), and osmoconditioning, which were compared to a dry seed control. Hardening and moisturizing treatments improved early emergence by as much as 20%, while osmoconditioning significantly lowered field emergence. Seed moisturizing and hardening also improved uniformity of emergence, and reduced the number of days required to attain 50% or 75% emergence. Seed hydration treatments were effective with the three levels (high, medium, and low) of seed quality and the three cultivars (‘Jubilee’, ‘Midway’, and ‘Reward’) studied.

The sorption of ammonia on californian chrysotile treated with boiling water and with aqueous solutions of sodium nitrate

Californian chrysotile asbestos modified by hydration treatments with boiling water and with aqueous solutions of sodium nitrate was applied as an adsorbent for ammonia at 298 K. Heats of adsorption and differential molar entropies of adsorption were determined through adiabatic calorimetry for low surface coverages of adsorped ammonia up to 12 μmol m -2. Nitrogen adsorption-desorption isotherms, pore size distributions and electron micrographs were also obtained. The very large heats of adsorption created by the initial doses of ammonia are thought to be related to the formation of ammonium hydroxide at high energy sites such as at vicinal hydroxyl groups generated during the hydration treatments. The singular effect of sodium ion inclusion was most noticeable at 15 kPa and above when the amount of ammonia adsorbed fell to a level close to 70% of that measured for the water-treated chrysotile. Ammonia adsorbed on the water-treated chrysotile was more mobile and gave values of the experimental differential molar entropy which were from 6 to 10 J K -1 mol -1 higher than those of the samples treated with an aqueous solution of sodium nitrate, depending on the surface coverage. Although surface chemical changes were induced by both treatments, the essentially fibrous physical structure of chrysotile asbestos appeared to be undisturbed.

Laboratory and Field Response of Preconditioned Upland Cottonseed to Minimal Germination Temperatures1

AbstractHydration of cottonseed (Gossypium hirsutum L.) prior to germination is known to desensitize the seed to chilling injury. Little has been reported, however, on the effects of these hydration treatments on germination and subsequent growth of cotton subjected to minimal germination temperatures, especially in the field. This study evaluated the effect of pregermination hydration treatments on stand establishment, seedling vigor, yield, and earliness of the crop. Hydration of ‘Acala 1517‐70’ cottonseed in water or saturated CaSO4 solution for 6 hours at 31 C, or in hot water for 1.5 min at 85 C and dried overnight in ambient air, stimulated germination and seedling elongation at 14 C in the laboratory. Preconditioned seed responded similarly at 14 C after chilling at 5 C for 24 hours. The effects of these treatments on emergence, seedling vigor, crop earliness, yield, and fiber properties were field evaluated ova a 2‐year period using several planting dates to provide a range of weather conditions. No advantages of using hydrated seed were demonstrated in the field tests as hydration of cottonseed decreased seedling vigor and, under favorable germination conditions, reduced stands.

The physiology of seed hydration and dehydration, and the relation between water stress and the control of germination: a review

Abstract Current interest in seed hydration treatments for the improvement of level, rate and uniformity of germination or field emergence has revealed how little is known of the physiology of germination control under water stress. This review surveys briefly the responses of seeds held at different hydration levels, from normal germination in a free water supply to seed activation without germination under slight moisture stress, seed deterioration at greater moisture stress and the damage that can be caused to seeds in very dry conditions, as well as the responses to subsequent dehydration. Inhibition of germination, though not of seed activation, at certain levels of water stress is likened to various forms of dormancy, and the mechanism governing the initiation of cell elongation is suggested as the possible key to control over germination. Several lines of evidence on cell membrane integrity and action, and their responses to external factors, point to the role that the membrane may play in cell elongation (and hence germination) control, and membrane integrity may also be associated with the transition between seed deterioration at one hydration level and seed activation and repair at slightly higher hydration levels. Seed activation without germination is also considered in an ecological context.