The use of water and some inorganic salt solutions to advance sugar beet seed. I. Laboratory studies

The emergence of sugar beet seedlings is often slow or irregular and insufficient plants may be established for the crop to yield fully. Treating the seed prior to sowing, such that the subsequent germination percentage is not reduced but germination is more rapid and better synchronised should be beneficial. A series of laboratory experiments was made to investigate seed treatment procedures involving water and various inorganic salt solutions. Many treatment combinations were identified which gave faster germination without decreasing germination percentage and left the seed dry and intact and suitable for sowing with conventional precision drills. No treatment was found which ‘primed’ the sugar beet seed and the term seed ‘advancement’ describes, more accurately, the effects observed. There was little difference in the performance of seeds optimally treated with water or some salt solutions generating an osmotic potential of between about –10 and –20 bars. However, the use of salt solutions, although more complicated, was preferred to water as inadvertent germination during treatment was less likely. The optimum treatment for the one bulk of sugar beet seed studied was, firstly, to wash the seeds for 3.5 h with water, then after air-drying, to moisten them on filter paper dampened with –15 bar (0–34 M) sodium chloride solution for 6 days at 15^oC followed by a final wash and air-drying.     

Some Aspects of the Reproductive Biology of Limonium vulgare Mill., and Limonium humile Mill.

The germination of two species of salt-marsh plants Limoniumvulgare Mill., and L. humile Mill., is investigated in relationto their ecology. Germination is inhibited by sea water, butgermination even in fresh water is low. Inhibition of germinationby sea water is negatively correlated with water uptake. However,a treatment in sea water stimulates subsequent germination infresh water. The effect of the sea-water treatment appears tobe one of osmotic shock which weakens the seed coat. Variationin response to the treatment is partly genetical and partlyenvironmental. Seeds in different parts of the salt-marsh willbe subject to differing conditions, both during seed developmentand during the interval between seed maturation and seed dispersal.In connection with this the effect of leaching by sea waterand fresh water is considered. The response to a sea-water treatmentvaries with time. Considered in the long term it shows somecyclical variation which might correspond with the tidal cycle.It is shown that seeds of Limonium can survive long periodsin sea water. There is a slow rate of germination during immersion.Most of those seeds which do not germinate in sea water surviveto germinate rapidly in fresh water. The response to oxygenconcentration, light, and temperature is also investigated.Experiments on seedling growth and establishment show the needfor fresh water and a suitable substrate. Mud gives a lowergermination but a higher survival, while sand gives a highergermination but a lower survival. The dispersal of Limoniumseeds in nature is investigated. Seeds of Limonium are mostabundant in the drift line, but even these only represent asmall fraction of the total produced. It is considered thatreproduction by seed is only important when a new area is beinginvaded. Subsequent reproduction is largely by vegetative spread.The ecological implications of the germination experiments arediscussed.     

云锦杜鹃种子萌发及对干旱胁迫的响应

以不同渗透势的PEG-6000溶液模拟干旱胁迫条件, 研究云锦杜鹃种子的萌发、幼苗生长和累积吸水率对干旱胁迫的响应。结果显示：种子于第14 d开始萌发,萌发期为8 d,总萌发率为45.5%±1.7%。在渗透势为-0.3～-0.6 MPa的溶液中, 种子的累计吸水率在第5 d就超过对照(蒸馏水中), 种子的萌发和幼苗的生长也优于对照, 说明云锦杜鹃种子不适合过于湿润的土壤环境中萌发。但溶液的渗透势≥-0.9 MPa时, 种子的吸水减缓、萌发率下降, 同时幼苗的生长也慢, 而当渗透势≥-1.8 MPa时, 种子不能充分吸涨、萌发, 说明云锦杜鹃种子对干旱胁迫比较敏感。另外, 经PEG溶液浸种2天后移入蒸馏水中,萌发率均有一定程度的提高, 其中经-0.3～-1.5 MPa的PEG溶液浸种后, 萌发率显著高于对照。提示用一定浓度范围的PEG溶液浸种可使休眠种子活化, 提高种子繁育的效率。     

On the modulation effect of pulsing and static magnetic fields and mechanical vibrations on barley seed hydration

The changes of wet and dry weights of barley seed in different periods of swelling were studied in seeds treated with Extremely Low Frequency Electromagnetic Fields (ELF EMF), Static Magnetic Fields (SMF) and Mechanical Vibrations (MV) in cold (4 degrees C) and warm (20 degrees C) distilled water as well as in seeds non-treated (control). The metabolic dependent seed hydration, dry weight loss and water binding in seed were modulated by preliminary EMF, SMF and MV-induced treatment of distilled water. The specific electrical conductivity (SEC) of control and treated distilled water was measured before the seed incubation. Frequency and intensity "windows" (i.e. range of frequency or intensity) for the effect of EMF, MV and SMF (correspondingly) on seed hydration, solubility and water binding in seed were studied. These "windows" were different in various phases of seed swelling. It is suggested that water structure modification is the result of valence angle changes (SMF and EMF) and dipole molecules vibration (EMF and MV) has different effects on the process of hydration, solubility and water binding in seed. These results are important from the point of understanding the mechanisms of the biological effect of EMF, as well as from the point of agriculture.     

Soy polyol formulations as novel seed treatments for the management of soil-borne diseases of soybean

Polyurethanes prepared from vegetable oils display a number of desirable properties useful for many commercial and industrial applications. One unique application is that of an agricultural seed treatment. Seed treatments are used to incorporate pesticides onto the seed coat and to decrease the disease susceptibility of the seed during its germination in the soil. In addition, by altering the movement of water across the seed coat and by incorporating protective pesticides in the coating, seed coating polymers can enhance the germination and survival of the seed under adverse environmental conditions. Soy polyols alone, and in combination with glycerin, polymerized with 4,4'-diphenylmethane diisocyanate (MDI) were studied for their seed treating properties and impact on soybean seed germination. The cross-linking density and properties of these polyurethane compounds were varied by changing the isocyanate/hydroxyl molar ratios. In order to optimize the coating qualities and to increase the efficiency of the coating, acetone was also studied as a diluting solvent to reduce the viscosity of the polyurethane mixture prior to polymerization on the seed coat. Optimal polymerization and resulting germination (95%) were obtained using a 1:1 isocyanate/hydroxyl molar ratio consisting of a mixture of soy polyol 180 and glycerin, and the use of an equal volume of acetone as a dilution solvent. This optimal polyurethane seed treatment had several desirable qualities including: reduced viscosity, decreased seed coating thickness, increased seed coating uniformity and permitted larger volumes of seed to be treated with the same volume of polymer. This optimal seed treatment increased the soybean seed germination by 15%, as compared with untreated seed. In addition, preliminary studies of the compatibility of these unique formulations with commercial and experimental fungicides also support the use of these polymers as seed treatments due to their enhanced stability, longevity and slow active ingredient water teaching characteristics. Compatibility of these seed coating polymers as formulations with captan, metalaxyl, thiabendazole and novel antimicrobial lipids and triterpenoid compounds display that the active ingredients can readily provide a zone of fungal inhibition around the seed as it germinates in the presence of Macrophomina phaseolino, causal agent of charcoal rot of soybeans. However, the release of the active ingredient from the polyol seed treatments is less affected by water leaching as compared to commercially available water-soluble seed treating polymer formulations. This is most likely due to the polyols unique polymer cross-linking characteristics. These results support the continued exploration of soy polyol derived polymers as seed coating compounds.     

Aqueous pathways dominate permeation of solutes across Pisum sativum seed coats and mediate solute transport via diffusion and bulk flow of water

The permeability of seed coats to solutes either of biological or anthropogenic origin plays a major role in germination, seedling growth and seed treatment by pesticides. An experimental set‐up was designed for investigating the mechanisms of seed coat permeation, which allows steady‐state experiments with isolated seed coats of Pisum sativum. Permeances were measured for a set of organic model compounds with different physicochemical properties and sizes. The results show that narrow aqueous pathways dominate the diffusion of solutes across pea seed coats, as indicated by a correlation of permeances with the molecular sizes of the compounds instead of their lipophilicity. Further indicators for an aqueous pathway are small size selectivity and a small effect of temperature on permeation. The application of an osmotic water potential gradient across isolated seed coats leads to an increase in solute transfer, indicating that the aqueous pathways form a water‐filled continuum across the seed coat allowing the bulk flow of water. Thus, the uptake of organic solutes across pea testae has two components: (1) by diffusion and (2) by bulk water inflow, which, however, is relevant only during imbibition.     

Polyethylene glycol 6000 priming effect on germination of aged wheat seed lots

The effects of PEG 6000 priming on germination performance of aged wheat seed lots have been studied. A correct application of osmopriming treatment indicated a relationship between the pattern of water absorption, the reactivation of mitotic activity and the start and synchronization of germination. The possibility of controlling pregerminative events by means of this treatment is discussed on the physiological basis of seed germination.     

羊草种子休眠机制及破除方法研究

羊草种子休眠程度深、发芽率低是限制栽培利用的重要因子.采用不同破除羊草种子休眠的方法,测定各处理对种子萌发的影响,以探索破除羊草种子休眠的有效途径.结果显示:(1)刺破种皮的裸种子较完整种子的萌发率、吸水速率、生活力分别由对照的6%、63%、0%显著增加到60%、86%、94%.(2)完整羊草种子分别用清水浸种1 d、30% NaOH浸种80 min、清水浸种1 d后用30% NaOH浸种60min其萌发率由6%分别显著提高到36%、60%、84%,而各浓度赤霉素处理完整种子其萌发率较对照均无显著变化. (3)采用清水浸种1 d后用30% NaOH处理60 min,再施加200 μg/g GA3综合处理,可使羊草完整种子的发芽率由6%提高到91%,接近其种子生活力94%.研究表明,羊草种子的稃与种皮不影响种子水分的吸收,但影响种子对GA3的吸收、不同程度地阻碍大分子物质的渗入、限制羊草种子内部萌发抑制物的渗出,从而引起种子休眠;分析认为稃和种皮以及种子内部萌发抑制物质是引起羊草种子休眠的主要原因.     

Respiration in barley seeds treated with mutagenic methyl methanesulphonate and stored at different water contents

In water soaked barley seeds the respiration rate (QO₂) at 25 °C is about 100 times higher at 30% than at 20% water content. The treatment of seeds with mutagenic methyl methanesulphonate led to the depression of the respiration rate in dependence on the applied mutagenic dose. Seed storage at 30% water content resulted in a recovery from the inhibition of seed respiration caused by methyl methanesulphonate. In contrast, at 20% seed water content the respiration rate either slightly decreased or remained unchanged in the course of storage. The results are discussed in relation to the previously described changes in the yield of induced mutagenic effects in barley seeds treated with monofunctional alkylating agents and stored at 30% and 20% seed water content.     

赤霉素和温水浸种对紫斑牡丹种子下胚轴萌发及其种胚解剖结构的影响

以紫斑牡丹种子为试验材料,采用不同浓度(0、100、300、500 mg/L)赤霉素(GA3)浸种和不同温度温水浸种(25、30、40和50℃)处理,考察各处理种子生根率的变化,并通过透射电镜观察不同生根发育时期种子种胚超微结构,探究赤霉素和温水浸种处理解除紫斑牡丹种子休眠进程中种胚超微结构变化以及这种变化与休眠解除的相关性。结果表明:(1)GA3和温水浸种均明显提前了紫斑牡丹种子生根时间,并以300 mg/L GA3和40℃温水处理的生根效果最好,分别较对照提前14.7 d和16.0 d,生根率分别达62.33%和67.00%。(2)光学显微镜观察发现,GA3、温水浸种处理较对照组紫斑牡丹种胚子叶的上、下表皮细胞形状及排列方式无明显影响,但其厚度均变薄,维管束结构明显,以300 mg/L GA3和40℃温水浸种处理生根效果最佳。(3)透射电镜观察发现,在各GA3浸种和温水浸种处理下,紫斑牡丹种子萌发前期,种胚子叶脂类物质出现降解现象,脂体呈大小不一的圆形或块状分布在细胞壁周边,数量明显减少,细胞核明显,核仁清晰,出现少量线粒体,细胞质内开始有蛋白质积累,在液泡的周围形成蛋白质沉积物;在种子萌发后期,种胚子叶细胞内物质稠密,脂体已降解融合成较大块状,细胞中储存的营养物质基本降解完全,内质网、高尔基体、线粒体等细胞器出现,结构更加完整,表明此时细胞内物质代谢活动加强,种子休眠解除,且300 mg/L GA3、40℃温水浸种处理种子种胚子叶结构变化最为明显。研究发现,300 mg/L GA3浸种和40℃温水浸种均可显著提高种子的萌发率,且40℃温水浸种的效果更好,在实际生产中建议使用温水浸种法。     

Value of waste water in agriculture. Evaluation of soil bacterial contamination, water table and plant culture]

The present study aim was to valorize the treated waste water as source of fertilizers for vegetables seed production and to assess the eventual bacteriological contamination risks of soil, plant and phreatic ground water table. The bacteriological analysis of drained water did not reveal any fecal coliforms vertical migration in depth and a low fecal contamination (thermotolerant coliforms) is limited to the levels of superficial horizons. The seed produced by using waste water showed a slightly fecal contamination which disappeared following treatment with a (5% chloride solution. The treated waste water improve the onion seeds production per hectare in spite of the increases of the phytopathogenic hazards.     

MOISTURE AND TEMPERATURE IN RELATION TO SEED STRUCTURE AND GERMINATION OF SUGAR PINE (PINUS LAMBERTIANA DOUGL.)

The typical, irregular, delayed germination of sugar pine seeds was studied under different conditions of environment and seed dissection. Individual seeds showed a 3-phase pattern of water uptake which was obscured when average values for groups of seeds were used. Stratification at 5 C slowed the rate of imbibition as well as the growth rate, but when followed after 3 months by return to 20 C, germination was uniformly rapid. Complete removal of the seed coats yielded prompt germination without stratification. The thin layer of the inner coat was a critical factor. Slitting this layer indicated less significance for gas exchange or mechanical restraint than for a restriction upon the rate of water uptake. Regardless of the method of seed treatment, the visible stages of germination consistently occurred within well-defined levels of water uptake. The delicate balance between water entry and use as well as the internal distribution of water within seed components should be evaluated, rather than a mere expression of the total amount of water in a seed.     

Boron application through seed coating improves the water relations, panicle fertility, kernel yield, and biofortification of fine grain aromatic rice

This study was conducted to evaluate the influence of boron (B) application through seed coating on leaf elongation, tillering, water relations, panicle sterility, kernel yield, and grain biofortification of fine grain aromatic rice. Boron was applied as seed coating at 1.0, 1.5, 2.0, 2.5, and 3.0 g B kg^?1 seed in two rice cultivars Super Basmati and Shaheen Basmati. Boron seed coating significantly affected the leaf elongation, water relations, panicle fertility, kernel yield and grain biofortification in both rice cultivars. However, seed coating with 1.0–2.0 g B kg^?1 seed was effective in improving the leaf emergence and elongation, and tillering. Whereas water relations (water and osmotic potential) were improved by all B seed coating treatments, but pressure potential was only improved from seed coating with 2.0–3.0 g B kg^?1 seed. Kernel yield was improved by all B seed coating treatments; however seed coating with 2 g B kg^?1 seed was the most effective treatment in this regard. Increase in kernel yield, by B seed coating, was attributed to decrease in panicle sterility. Leaf and kernel B contents were increased with increase in B concentration in seed coating.     

香圆种子萌发特征及催芽技术

以香圆（Citrus wilsonii Tanaka）种子为实验材料,通过测定种皮透水性、种皮机械障碍、发芽温度等对种子萌发的影响从而探讨种子萌发特征;通过切割种子、热水浸种、赤霉素浸种、低温层积等处理方式探索种子的催芽方法。结果显示：香圆种皮不存在透水性障碍,但其机械障碍对种子萌发具有抑制作用,且内种皮对萌发影响较大;种子在15℃、25℃、35℃恒温及15℃/30℃变温条件下均可萌发,其最适萌发温度为25℃;采用低温层积、热水浸种、切除1/3种子等方法均可一定程度上促进种子萌发。生产中宜采用始温60℃热水浸种24h的方法对香圆种子进行催芽。     

水杨酸调控盐胁迫下羽衣甘蓝种子萌发的机理

盐胁迫是植物种子萌发与植株生长的重要限制因子。以羽衣甘蓝(Brassica oleracea var.acephala)名古屋为材料,研究不同盐分对其种子萌发的影响,探索水杨酸(SA)及其合成抑制剂氨基茚磷酸(AIP)处理对羽衣甘蓝种子萌发的调控效应。实验结果表明,150与200 mmol·L^–1 NaCl处理后的羽衣甘蓝种子活力显著降低。盐胁迫显著降低种子的吸水速率、种子活力与幼苗质量,降低苯丙氨酸裂解酶活性与内源SA含量,提高过氧化氢(H2O2)与超氧阴离子(O2^–.)含量。SA可以缓解盐胁迫对羽衣甘蓝种子活力的抑制作用,通过促进内源SA合成,从而提高种子吸水率与种子活力,促进种子对K^+、Mg^2+的吸收,降低Na+含量。此外,外源施加SA能够显著增强超氧化物歧化酶和过氧化物酶活性,降低H2O2与O2^–.的积累。相反,氨基茚磷酸(AIP)处理能够增强盐胁迫对种子萌发的抑制作用,推测这与AIP处理能够显著降低种子内源SA含量密切相关。研究表明外源SA主要通过提高保护酶活性、降低活性氧积累和维持体内离子平衡来增强羽衣甘蓝的耐盐性。     

Transition from hormonal to nonhormonal regulation as exemplified by seed dormancy release and germination triggering

It is generally believed that seed dormancy release is terminated by germination and that this process is controlled by phytohormones. Most attention was paid to gibberellins (GAs) because treatment with GAs is most frequently applied for seed dormancy breaking. The review characterizes the hormonal regulation of seed dormancy and its release, as exemplified by arabidopsis seeds possessing non-deep physiological dormancy. Dormancy release occurs under the influence of low temperature and/or illumination with red light. Two main trends are typical of this process: (1) a decrease in ABA content and blocking of signal transduction from ABA, and (2) GA synthesis and activation of GA signaling pathway. Dormancy release ends with the GA-induced syntheses of some proteins, enzymes in particular, required for the start of germination. Quiescent seeds are capable of realizing the germination program without hormonal induction, due to nothing but seed hydration. In imbibing seeds, the triggering role of water lies in the successive activation of basic metabolic systems after attaining the water content thresholds characteristic of these systems and in preparing cells of embryo axial organs for germination. Thus, seed dormancy release is controlled by phytohormones, whereas subsequent germination manifesting itself as the initiation of cell elongation in embryo axes is controlled by water inflow.     

濒危植物中甸刺玫种子休眠及其生态学意义

对中甸刺玫Rosa praelucens种子结构及其透水性,赤霉素处理对胚的影响,果壳、种皮、胚乳的粗提物活性进行研究。结果表明：(1) 中甸刺玫外种皮是由多层排列紧密的厚壁细胞组成,内种皮为坚硬致密的栅栏组织;(2) 种皮对种子的吸胀阻碍较大, 未处理的种子吸水率较低,吸水13 d后增加量为18.82%;(3) 果实结籽率为0.69%,多数果实中没有饱满的种子;(4) 赤霉素100 mg·kg-1预处理种子可加快胚的萌发速率;(5) 胚乳、种皮、果壳中存在内源抑制物。中甸刺玫种子的休眠是由其形态和生理特点引起的综合休眠。     

Modeling Analysis on Germination and Seedling Growth Using Ultrasound Seed Pretreatment in Switchgrass

Switchgrass is a perennial C4 plant with great potential as a bioenergy source and, thus, a high demand for establishment from seed. This research investigated the effects of ultrasound treatment on germination and seedling growth in switchgrass. Using an orthogonal matrix design, conditions for the ultrasound pretreatment in switchgrass seed, including sonication time (factor A), sonication temperature (factor B) and ultrasound output power (factor C), were optimized for germinating and stimulating seedling growth (indicated as plumular and radicular lengths) through modeling analysis. The results indicate that sonication temperature (B) was the most effective factor for germination, whereas output power (C) had the largest effect on seedling growth when ultrasound treatment was used. Combined with the analyses of range, variance and models, the final optimal ultrasonic treatment conditions were sonication for 22.5 min at 39.7°C and at an output power of 348 W, which provided the greatest germination percentage and best seedling growth. For this study, the orthogonal matrix design was an efficient method for optimizing the conditions of ultrasound seed treatment on switchgrass. The electrical conductivity of seed leachates in three experimental groups (control, soaked in water only, and ultrasound treatment) was determined to investigate the effects of ultrasound on seeds and eliminate the effect of water in the ultrasound treatments. The results showed that the electrical conductivity of seed leachates during either ultrasound treatment or water bath treatment was significantly higher than that of the control, and that the ultrasound treatment had positive effects on switchgrass seeds.     

超干种子耐贮藏性的细胞学及生理生化基础

种子超干贮藏是近年来种子生物学研究和植物种质资源保存领域的研究热点。本文综述了种子超干贮藏研究的进展 ,包括 :(1)超干种子的细胞和亚细胞结构变化 ;(2 )超干处理对种子水分状态的影响以及与劣变反应速率的关系 ;(3)超干种子中的自由基伤害和有毒物质的积累 ;(4)超干种子中的内源抗氧剂 ;(5 )糖类物质以及两性物质对极度脱水种子细胞的保护。此外 ,还对此领域的研究进行了展望     

Germination and water dispersal of seeds from a threatened plant species Penthorum chinense

To conserve a threatened plant species (Penthorum chinense Pursh) in Japan, seed germination responses to pretreatment (imbibition and/or chilled), temperature and light, and seed dispersal by water were examined. The seeds collected from abandoned paddy fields in a warm temperate region, central Japan, germinated in light (14 h photoperiod; light 22°C, dark 21°C) after a moist-chilled treatment. After this pretreatment, the seeds germinated well at 10–25°C (optimum temperature 15°C), but did not germinate in darkness even at the optimum temperature. Most of the seeds floated on distilled water, but 20–60% of the seeds that were collected from several populations sank in distilled water, indicating dimorphism in seed dispersal by water. The floating and sunken seeds did not show significant differences in weight and germination rate within a population. The addition of a surface-active agent in distilled water submerged the seeds, indicating that the buoyancy of the seeds is attributable to an oil coating on the seed surface that enhances the interfacial tension on the seeds. Three times the number of seeds sank in river water collected from a rural area than in distilled water. A greater number of seeds also sank in water that had increasing concentrations of linear alkylbenzenesulfonate, which is a major component of synthetic detergents. This suggests that the water dispersal of this species is suppressed by surface-active agents, including detergents, in river water.