Long term t in vitro storage of lily: effects of temperature and concentration of nutrients and sucrose

Methods for long-term preservation of lily germplasm were examined. t In vitro regenerated bulblets of 10 lily (t Lilium L.) genotypes (Asiatic hybrids, Oriental hybrids, t L. longiflorum and t L. henryi) were stored for 28 months at -2 °C and 25 °C on four different media: 1/4 or full strength Murashige and Skoog nutrients with 9% (w/v) or 6% sucrose. Sprout growth, bulb growth, and viability were determined. The combination of 1/4 strength MS nutrients and 9% sucrose gave the highest reduction in sprout and bulb growth, the highest viability and the highest percentage of regrowth after 28 months of storage. At 25 °C, all lily genotypes survived 28 months of storage under these conditions. At -2 °C, Asiatic and Oriental hybrids survived 28 months of storage, whereas genotypes of t L. longiflorum and t L. henryi survived 6 months of storage, but died during prolonged storage. This revised version was published online in June 2006 with corrections to the Cover Date.     

保存介质和温度对西伯利亚鲟卵子短期保存的影响

研究了不同保存介质(体腔液CF、Hepes液、RMS液)、温度(4℃、16℃)和保存时间(4 h、8 h、16 h、24 h)对西伯利亚鲟卵子短期保存的影响.结果显示:保存介质、温度和时间对卵子受精率、孵化率和初孵仔鱼畸形率有显著性影响(P<0.05),受精率、孵化率均随保存时间的延长而下降,畸形率上升.16℃条件下保存卵子受精率、孵化率和畸形率均高于4℃,但4℃下卵子的保存时间较16℃下长.研究表明,采用根据西伯利亚鲟体腔液生化成分配制的Hepes液作为保存介质,于16℃下保存4 h为西伯利亚鲟卵子的最佳保存条件,此时受精率、孵化率和畸形率分别为86.36%、94.74%和0.     

Effects of 1-methylcyclopropene alone and in combination with polyethylene bags on the postharvest life of mango fruit

Experiments were conducted to determine how 1‐methylcyclopropene (1‐MCP) treatments influence ethylene‐stimulated ripening of harvested mango cv. Zihua fruit at 20°C. The ripening response of fungicide (prochloraz) treated fruit was characterised following various 1‐MCP treatments in sealed jars followed by storage in polyethylene bags and/or subsequent ethephon (ethylene) exposure. Exposure of fruit to increasing concentrations of 1‐MCP for 12 h resulted in the reduced softening of produce when subsequently held in air for 7 days after ethephon treatment. Application levels of between 1 and 100 μl litre^?1 1‐MCP had increasing impact, while 200 μl litre^?1 1‐MCP apparently began to approach response saturation. Exposure of fruit to 50 or 100 μl litre^?1 concentrations of 1‐MCP for periods from 1 to 24 h subsequently resulted in reduced softening of produce when held in air for 7 days after ethephon treatment. Increasing periods of exposure from 1 to 12 h had increasing impact, while exposure times greater that 12 h appeared to reach saturation. In the absence of ethephon‐stimulation, the natural ripening of mangoes held in polyethylene bags was delayed by prior exposure to 100 μl litre^?1 1‐MCP for 12 h. Extended holding of 1‐MCP treated and non‐1‐MCP treated control fruit in polyethyene bags encouraged physiological and pathological deterioration. Following exposure to 100 μl litre^?1 1‐MCP for 12 h, mango fruit held for 10 days in polyethylene bags showed a delay in the onset of ripening relative to bagged but non‐1‐MCP treated control fruit. Treatment with 1‐MCP allowed storage of mango fruit in plastic bags at 20°C for 30 days. Observations suggest that 1‐MCP treatments do not adversely influence the quality of the post‐storage ethephon‐ripened fruit. Thus, application of 1‐MCP in combination with the use of polyethylene bags can extend the postharvest life of mango fruit at ambient temperature. Treatments that extend postharvest life are important in developing countries, such as China, where the cold chain infrastructure is often lacking.     

Low-ethylene storage of apples cv. 'Cox's Orange Pippin': effects of 'Rapid CA' and ultra-low oxygen

Three methods of reducing ethylene accumulation in the flesh of apple fruits cv. ‘Cox's Orange Pippin’ during controlled atmosphere storage were compared with one another and with a control. They were: (a) rapid establishment of storage conditions, (b) treatment with 5% CO₂ for 15 days prior to long-term storage, and (c) lowering storage O₂ from 1.25% to 0.75%. In all cases ethylene was either allowed to accumulate or maintained below 1 μl litre^-1. When ethylene was removed from the storage atmosphere all three methods reduced internal ethylene concentrations. Although the firmness of fruits from two orchards was affected differently by ethylene removal, the effects on the retention of flesh firmness by ethylene removal and storage in 0.75% O₂ were generally additive. No adverse effects of storage in 0.75% O₂ were observed.     

Effects of vegetable type, package atmosphere and storage temperature on growth and survival of Escherichia coli O157:H7 and Listeria monocytogenes

The survival and growth of Escherichia coli O157:H7 (ATCC 43888 and NCTC 12900) and Listeria monocytogenes (ATCC 19114 and NCTC 11994) during storage (4 and 8°C) on ready-to-use (RTU) packaged vegetables (lettuce, swedes (rutabaga), dry coleslaw mix, soybean sprouts) were studied. The vegetables were sealed within oriented polypropylene packaging film, and modified atmospheres developed in packs during storage due to produce respiration. Survival and growth patterns were dependent on vegetable type, package atmosphere, storage temperature and bacterial strain. Populations of L. monocytogenes and E. coli O157:H7 increased (P<0.05, by 1.5 to 2.5 log cycles, depending on strain) during a 12-day storage period on shredded lettuce (8°C). L. monocytogenes populations also increased (by ∼1 log cycle) on packaged swedes, did not change significantly (P>0.05) in packages of soybean sprouts and decreased by ∼1.5 log cycles (P<0.05) on coleslaw mix (8°C). E. coli O157:H7 populations on packaged coleslaw and soybean sprouts increased (by 1.5 to 2.5 log cycles) up to day 5, but declined during subsequent storage (8°C). On packaged swedes (8°C), populations of E. coli O157:H7 strain ATCC 43888 increased (by ∼1 log cycle) during storage, whereas populations of strain 12900 increased between days 2 and 5, and declined during subsequent storage. Reducing the storage temperature from 8 to 4°C reduced the growth of L. monocytogenes and E. coli O157:H7 on packaged RTU vegetables. However, viable populations remained at the end of the storage period at 4°C. Journal of Industrial Microbiology & Biotechnology (2001) 27, 111–116. Received 25 May 2000/ Accepted in revised form 21 September 2000     

Water balance in the sugarbeet root maggot Tetanops myopaeformis,during long‐term low‐temperature storage and after freezing

The sugarbeet root maggot Tetanops myopaeformis Röder (Diptera: Ulidiidae) can be stored in moist sand at 4–6 °C for up to 5 years and is freeze‐tolerant. The majority of stored larvae survive in a state of post‐diapause quiescence and the remainder are in a multi‐year diapause. The present study aims to determine larval water content and water loss rates in diapausing and low‐temperature stored larvae. Body water content ranges from 57% to 70.1%. Two distinct groupings of larvae are revealed based on dry weights. The first group consists of the diapausing larvae and larvae stored for 1 year. This group has significantly higher dry weights than the second grouping, which consists of the larvae stored for 2 and 3 years. There are no significant differences within each group. Larval water losses follow a first‐order kinetic relationship with time. Larvae stored for 2 years lose water at a significantly higher rate than diapausing larvae. Larvae exhibit no active water uptake at storage temperatures. A freezing event does not induce a significant decrease in wet weights, nor does it increase larval water loss rates. These results indicate that metabolic water and the microclimate during storage are key factors enabling the long‐term survival of T. myopaeformis larvae during low‐temperature storage, and may provide insights for maintaining other insect species under similar conditions.     

套袋苹果不同类型果袋内温、湿度变化特征及其对果实外观品质的影响

研究了套袋苹果果实发育过程中不同类型果袋内温、湿度的变化以及果袋对果实外观品质的影响.结果表明:果袋内的温度和湿度变化呈负相关,一天中袋内温度从9:00开始迅速升高,最高温度在春秋季一般出现在13:00-14:00,盛夏一般出现在13:00-17:00,最低温度出现在5:00前后,最高湿度出现在6:00前后.不同类型的果袋温、湿度变化不同,特别在高温和阴雨天差异明显,最高温度表现为双层袋》单层袋,而最高湿度表现为单层袋》双层袋.高温往往伴随极度干燥,当袋内温度超过35 ℃时,微域湿度一般低于40%.套袋对苹果果实品质有重要影响,果实外观品质以双层袋较好、单层袋较差;而双层袋中又以XL袋效果最好.     

保存时间及温度对大肠杆菌感受态转化效率的影响

通过不同保存时间和温度对大肠杆菌感受态转化效率影响的研究,更明确阐明了不同保存温度下感受态细胞随保存时间的延长其转化率的变化趋势,为以后的研究提供了量化的指标。     

不同日龄七星瓢虫成虫和蛹的低温储存研究

为明确七星瓢虫Coccinella septempunctata Linnaeus不同日龄的虫体经低温储存后的存活差异并获取最佳的储存虫龄和时间。分别选择羽化后0、3、7、14、21和28 d的成虫和化蛹1、2、3和4 d的蛹在8℃进行低温储存试验,确定不同储存时间（7、14、21、28、35和45 d）后虫体的存活率或羽化率。结果显示：不同日龄（0~21 d）的瓢虫成虫,存活率与储存期呈显著负相关关系。日龄＞7 d的瓢虫成虫,经低温储存21 d后,存活率为80%左右,储存28 d后,存活率仍大于70%。日龄＞14 d的瓢虫成虫储存45 d后还有60%以上存活。不同日龄的蛹最终羽化率不同,1~2 d蛹在储存21 d后羽化率为70%左右,高于3~4 d蛹的50.00%和13.33%。结果表明,七星瓢虫成虫羽化14 d后在低温下储存期最长可达45 d,可在长期储存时使用。储存期不高于28 d时,可选用羽化7 d的成虫。储存期低于21 d时,可选用羽化7 d的成虫或1~2 d蛹,其中1~2 d蛹最为经济。     

Effects of temperature and storage length on seed germination and the effects of light conditions on seedling establishment with respect to seed size in Ligularia virgaurea

Ligularia virgaurea is widely distributed in the alpine meadows of the eastern Qinghai-Tibet plateau. We studied the effects of temperature and seed storage length on seed germination in a laboratory experiment, the effects of seed mass and light intensity on seed emergence in a pot experiment, and the effect of meadow disturbance intensity on seed emergence in a field experiment. Our results showed that seeds of L. virgaurea germinated well under a wide range of temperatures. Germination percentage decreased with increased seed storage length. When seeds were stored for either 6 or 12 months the germination percentage increased with decreasing temperature. The emergence percentage of large seeds was higher than that of small seeds. Seedling survival of large seeds was greater than that of small seeds in 75% and 50% of natural irradiance. Large seeds of L. virgaurea were more successful colonizers in the alpine meadows. Seeds of L. virgaurea germinated in both disturbed meadows and non-disturbed meadows, but seed emergence and seedling establishment were higher in the disturbed meadows, that is, disturbance could facilitate the recruitment and establishment of L. virgaurea .     

桃花粉低温和超低温保存方法比较研究

桃(Prunus persica(L.)Batsch)是我国重要的无性繁殖作物种质资源,目前主要保存于3个国家无性繁殖作物种质圃。随着以茎尖、花粉、休眠芽为保存载体的超低温保存技术的发展,超低温保存已成为无性繁殖作物重要备份保存方式。本研究以15份桃种质花粉为研究对象,开展含水量、回湿处理和保存温度(4℃低温保存和液氮超低温保存)对保存后花粉离体萌发率的影响研究。研究结果:明确了桃种质花粉超低温保存的含水量;揭示了回湿处理对部分桃种质花粉超低温保存产生显著影响;超低温保存后花粉离体萌发率最高可达83%;4℃低温保存和超低温保存比较研究结果表明,超低温保存4年后14份桃种质花粉离体萌发率仍可保持30%以上,11份桃种质花粉离体萌发率与保存前花粉离体萌发率相比无显著变化甚至显著提高,而4℃低温保存的花粉离体萌发率降至0。该研究为国家种质库建立花粉规模化超低温保存提供技术支撑。     

Seed storage in polyethylene bags of a recalcitrant species (Quercus ilex): analysis of some bio-energetic and oxidative parameters

Some technological and physiological aspects were analysed during seed storage of holm oak (Quercus ilex L.), a typical Mediterranean recalcitrant species. Considering the mild dormancy and desiccation sensitivity of these seeds, the influence of the storage environment on viability was examined. Acorns were maintained at low temperature and at high moisture content either inside thin polyethylene bags or mixed with peat in a bin. Storage in polyethylene bags, if compared with peat treatment, maintained optimal seed quality parameters. The effects of the two treatments on some physiological parameters were analysed during 1-year seed storage. Acorns stored in a bin with peat started to germinate early and exhibited a more rapid seed deterioration caused by metabolism-linked oxidative damage. The latter phenomenon was linked to a higher respiration and H₂O₂ level, induction of catalase activity, as well as lowered glutathione pool and ATP content. In addition, a more oxidized redox poise was observed. On the contrary, the plastic film of polyethylene, limiting gaseous exchanges, maintained acorn metabolic activity at low levels and allowed the accumulation of ethylene inside the storage atmosphere. These factors, inducing a dormant-like state, could have played a crucial role in prolonging seed storage.     

Effects of storage temperature and sucrose on bulblet growth, starch and protein contents in in vitro cultures of Hyacinthus orientalis

The scale segments of the bulblets of Hyacinthus orientalis L. cv. Anna Marie were examined to improve their growth and development with cold-pretreatment and sucrose. The cold-pretreated (4 °C for 4 months) segments showed higher growth and better development of the bulblets on medium without sucrose than ones stored at 20 °C. A rapid decrease in starch content of bulb pieces was found during the first 2 weeks in all cultures and thereafter the content decreased gradually. A scanning electron microscopic observation during the bulblet growth and development showed a gradual decreasing trend of the starch granules from 2 to 16 weeks of the cultures. SDS-PAGE electrophoresis revealed the presence of a characteristic polypeptide of approximately 45 kD, which is assumed to be a major storage protein in the bulblets.     

温度和光周期对管侧沟茧蜂滞育诱导及滞育茧的低温冷藏

【目的】为明确诱导管侧沟茧蜂Microplitis tuberculifer 滞育的主要因子,在田间和室内研究了不同温度和光周期下管侧沟茧蜂的滞育率和滞育茧的最佳冷藏温度。【方法】田间实验分别从8月31日到9月25日每隔5 d在室外罩笼内释放管侧沟茧蜂寄生的粘虫幼虫,待寄生蜂结茧后统计子代蜂的滞育率。室内实验共设5个不同温度（16℃, 18℃, 20℃, 22℃和24℃）和7个不同光周期（6L:18D, 8L:16D, 10L:14D, 12L:12D, 14L:10D, 16L:8D和18L:6D）,分别统计寄生蜂在各个处理条件下的滞育率。【结果】在河北中部地区秋季自然条件下,8月底当日平均气温为24.4℃,日平均光照时间为12 h 51 min 时,少数蛹（5.08%）开始进入滞育;9月25日,当日平均气温为17.2℃,日平均光照时间为11 h 36 min以下时,几乎所有蛹个体进入滞育,滞育率达到99.70%。在室内人工控制条件下,当温度为22℃以上,无论光周期如何变化,管侧沟茧蜂不能进入滞育,所结茧全部为非滞育茧。温度为22℃以下存在光周期反应,在温度16℃, 18℃和20℃,光周期10L:14D时形成滞育茧数量最多,滞育率分别为100%, 89.75% 和 29.58%。可见温度和光周期二者共同影响管侧沟茧蜂的滞育。滞育茧在0℃左右条件下冷藏 240 d 和5℃左右环境条件下冷藏180 d, 成虫的羽化率和寄生能力与发育茧差异不显著(P>0.05);0℃条件下冷藏300 d,滞育茧仍有79%可以正常羽化。【结论】该寄生蜂在秋季进入滞育主要是低温条件和短光照反应相互作用的结果,滞育茧在0℃和5℃温度下至少可以保存240 d。这些结果对管侧沟茧蜂的大规模繁殖和滞育茧的保存具有重要参考价值。     

Global terrestrial carbon storage and uncertainties in its temperature sensitivity examined with a simple model

The future of the land carbon sink is a significant uncertainty in global change projections. Here, key controls on global terrestrial carbon storage are examined using a simple model of vegetation and soil. Equilibrium solutions are derived as a function of atmospheric CO₂ and global temperature, these environmental variables are then linked in an idealized global change trajectory, and the lag between the dynamic and equilibrium solutions is derived for different linear rates of increase in atmospheric CO₂. Terrestrial carbon storage is departing significantly from equilibrium because CO₂ and temperature are increasing on a similar timescale to ecosystem change, and the lag is found to be proportional to the rate of forcing. Thus peak sizes of the land carbon sink, and any future land carbon source, are proportional to the rate of increase of CO₂. A switch from a land carbon sink to a source occurs at a higher CO₂ and temperature under more rapid forcing. The effects of parameter uncertainty in temperature sensitivities of photosynthesis, plant respiration and soil respiration, and structural uncertainty through the effect of fixing the ratio of plant respiration to photosynthesis are explored. In each case, the CO₂ fertilization effect on photosynthesis is constrained to reproduce the 1990 atmospheric CO₂ concentration within a closed global model. New literature compilations are presented for the temperature sensitivities of plant and soil respiration. A lower limit, Q₁₀=1.29, for soil respiration significantly increases future land carbon storage. An upper limit, Q₁₀=3.63, for soil respiration underpredicts the increase in carbon storage since the Last Glacial Maximum. Fixing the ratio of plant respiration to photosynthesis (R/P) at 0.5 generates the largest and most persistent land carbon sink, followed by the weakest land carbon source.     

Iron formulation affects in vitro storage of hops: An image analysis

Summary In vitro-stored plant germplasm is usually evaluated by visual analysis of the plant based on subjective characters. To reduce the variability in these evaluations, we developed a digital-image evaluation system for in vitro-stored plantlets. This study compares the standard visual evaluation system with a digital analysis system to determine if digital analysis can effectively quantify the health of diverse Humulus germplasm. Eight cultivars of Humulus lupulus L. were stored on standard Murashige and Skoog (MS) medium with iron alone (EDTA chelated) and on MS iron with 100 or 200 mgl^&#x2212;1 sequestrene 138 iron (EDDHA chelated). Digital images of the upper two nodes of each plantlet were evaluated for red, green, blue, green/red ratio, and modified normalized difference vegetation index (MNDVI=R-G/R+G). Evaluation of each plantlet for MNDVI values showed consistent significant differences for all treatments only at the upper node. Significant differences for visual and the MNDVI values among the three iron treatments were observed at the upper node of most of the eight hop cultivars. Regression analysis of the upper node MNDVI values vs. whole-plant visual ratings showed positive correlations for most cultivars. Effects of iron treatments on storage duration were also analyzed for both visual and digital systems. There were significant differences among MNDVI values for plantlets stored on medium with standard MS iron alone (EDTA chelated) and with the addition of sequestrene 138 iron. In general, the MNDVI value of the upper node correlated well with visual ratings and could be used to determine the health of in vitro stored hops.     

Seasonal pattern of accumulation and effects of low temperatures on storage compounds in Trifolium repens

The seasonal pattern of concentrations of nitrogen, starch and vegetative storage protein (VSP) in stolons of Trifolium repens L. grown in the field were studied. Two different genotypes, cv. Aran and cv. Rivendel, differing in their morphology (stolon thickness and branching rate) but with similar growth rates, were used. Maximum concentrations of starch were found in summer whereas hydrolysis of starch took place throughout winter, suggesting that C storage is more important for winter survival than for promotion of early spring growth. On the other hand, VSP and nitrogen accumulated in autumn and early winter and then decreased when growth was resumed during early spring. For both cultivars, an inverse relationship was found between VSP concentration in stolons and mean air temperature, suggesting that VSP accumulation may be triggered by low temperature. Further experiments with plants grown under different regimes of temperature and daylength, suggested that VSP synthesis is stimulated by low root temperatures, with a slight synergistic effect of short daylength.
The effects of root temperature on growth, N₂ fixation, NH₄⁺ uptake and N allocation within Trifolium repens L., were studied under controlled conditions. The shoot growth rate was greatly reduced when root temperatures were lowered from 12 to 6°C, while the rate of stolon growth was less affected. Low root temperatures inhibited N2 fixation more than it did NH₄⁺ uptake, but the relative allocation of N to stolons was increased. Lowering root temperature also increased the accumulation of VSP in stolons. These results are discussed in terms of the mechanism associated with low temperature stimulation of VSP accumulation and its coupling with changes in the source/sink relations for allocation of N, between growth and storage.     

Chilled storage of Asian seabass,Lates calcarifer Bloch semen: Effects of ions,extenders and storage periods on sperm quality and fertilization ability

The development of a chilled storage protocol of fish sperm requires an understanding of sperm biology and function as the activation/inhibition of fish sperm is greatly affected by several environmental factors. This study aimed to determine the effects of ionic and non-ionic solutions, extender types (Ringer's solution, Ca-F HBSS solution, HBSS solution, He and Wood solution, Saline solution, and Modified Cortland solution), and chilled-storage period on sperm quality and fertilization ability of Asian seabass, Lates calcarifer semen. Regulation of Asian seabass sperm motility was dependent on the osmolality of both ionic and non-ionic activation media. The threshold levels on the initiation of sperm motility were detected in KCl (>100 mM), NaCl (>50 mM), CaCl₂ (>50 mM), glucose (>300 mM), and mannitol (>100 mM) solutions. Relatively high percentages of sperm motility (>80%) were observed when activated with KCl, NaCl, CaCl₂, glucose, and mannitol solutions at above 700, 600, 350, 1,000, and 1,000 mM, respectively. Ringer's solution was the most optimal extender for chilled storage of Asian seabass semen at 2–4°C supported by the retention of sperm motility and viability for 6 days. Semen diluted in Ringer's solution and chilled-stored for 2 days exhibited acceptable fertilization (66.1% ± 6.2%) and hatching (56.4% ± 2.9%) rates. This report, for the first time, describes the ionicity and non-ionicity effects on the motility of Asian seabass sperm.     

米蛾卵繁育的螟黄赤眼蜂的适宜冷贮温度和虫龄

为了全面评价冷贮对米蛾Corcyra cephalonica Stainton卵繁育螟黄赤眼蜂Trichogramma chilonis Ishii的影响, 本试验采用米蛾卵为寄主, 以冷贮温度（3和10℃）、 冷贮虫龄（以接蜂开始时间为起点, 接蜂后1, 2, 3, 4, 5, 6, 7, 8和9日龄）和冷贮时间（1, 2, 3和4周）为试验因子, 研究了冷贮对螟黄赤眼蜂活蛹率、 羽化率和畸形率的影响。结果表明： 3个因素均能单独或互作显著影响活蛹率、 羽化率和畸形率（P＜0.05）。综合各冷贮虫龄对低温的反应, 螟黄赤眼蜂对3℃较敏感, 此温度下1-3日龄的活蛹率和各虫龄的羽化率均显著下降（P＜0.05）, 不适宜长期冷贮; 10℃下各虫龄的活蛹率受冷贮时间的影响不显著, 1-3日龄的羽化率受冷贮时间的影响也不显著, 冷贮4周后仍有74%以上的羽化率, 10℃适宜冷贮。不同冷贮温度下冷贮适宜虫龄不同。在10℃下, 最适冷贮虫龄是3日龄的赤眼蜂, 此虫龄不同冷贮时间的活蛹率（74.09%～77.59%）和羽化率（74.26%～90.37%）均与对照无显著差异（P>0.05）, 但显著高于其他虫龄（P＜0.05）。此虫龄在10℃下冷贮1~3周, 畸形率在27%以内。结果表明米蛾卵内螟黄赤眼蜂不同冷贮温度下适宜冷贮虫龄不同。