鲜花生、嫩玉米常温保鲜技术

鲜花生、嫩玉米营养丰富,清香可口,城乡畅销,利用农家房舍,不用购置任何设备,4m2的闲房可贮一亩地的产品,就象贮存红薯和大白菜一样方便,家家能贮藏,人人会保鲜。保鲜剂可使嫩玉米、鲜花生的营养风味久存不变,只要将玉米、花生经保鲜剂处理浸泡,保鲜10个月时仍风味不变,任凭气候变化,夏秋贮藏,冬春反季节供应市场。98年以来的国内试点证明,保鲜效果不但不受南北气候影响,亩增产值数倍,是入世后调整农业产品市场结构的新法之一。2001年8月26日在人民大会堂举行的新技术推介会上引起了众多媒体和各界的高度好评,中央电视台七套于8月28日给予充…     

壳聚糖与有益微生物组合的生物保鲜剂用于丰都红心柚常温贮藏试验

丰都红心柚系从丰都县实生普通红心柚混杂群体中选育出的中熟红柚新品种,以其果肉色泽红艳,汁多化渣,酸甜可口,无核无异味的优良品质深受消费者青睐,多次评为部、省优质果品,2001年获中国名牌产品殊荣.迄今,已建生产基地4800km^2,部分柚园已试投产,年产果近万吨.为延长市场供应期和缓解成熟期过于集中所造成的种种压力,对其进行贮藏保鲜仍然是最有效的途径.但随着病原菌抗性逐渐增强以及消费者对果品质量安全要求不断提高,人们日益关注化学防腐保鲜剂的潜在危害,开发天然的、无公害高效的生物保鲜剂已越来越受到科技工作者的重视并取得显著成效.本试验是对高分子质量壳聚糖进行降解,形成更具生理活性的低分子质量壳聚糖（夏文水,1998）,并与有益微生物适当组合,配制成发挥二者功能的新型生物保鲜剂,用于丰都红心柚常温贮藏条件下防腐保鲜.     

The influence of constant and diurnally changing CO2 concentrations on plant growth and development

Plants of Ficus benjamina and miniature rose (Rosa hybrida cv. Red Minimo) were grown under four CO₂ treatments. Two had constant CO₂ levels (600 and 900 ppm) and the other two had diurnal changes in CO₂ levels, one increasing from 600 to 1500 ppm and one decreasing from 1500 to 600 ppm, each in four steps of 300 ppm during the day-time. In all treatments 900 ppm CO₂ was maintained during the night when supplementary light was used, except in the treatment with constant 600 ppm where 600 ppm was also continued throughout the night. Plant growth was monitored under both decreasing and increasing natural daylength and irradiance. The tallest plants and greatest increment in height for Ficus occurred with plants grown under constant CO₂ concentration at 600 ppm and also with increasing CO₂ concentration. In both experiments the dry weight per pot was lowest when plants were grown under a constant CO₂ concentration at 900 ppm. In both experiments with miniature roses the number of flower buds was significantly increased under diurnally changing CO₂ concentration or when the CO₂ level was constant at 600 ppm compared with a constant 900 ppm. Time to flowering was decreased by constant CO₂ at 900 ppm as compared with the other treatments.     

The effects of day and night temperature on Chrysanthemum morifolium: investigating the safe limits for temperature integration

Summary

The impact of day and night temperatures on pot chrysanthemum (cultivars ‘Covington’ and ‘Irvine’) was assessed by exposing cuttings, stuck in weeks 39, 44, and 49, to different temperature regimes in short-days. Glasshouse heating set-points of 12°, 15°, 18°, and 21°C, were used during the day, with venting at 2°C above these set-points. Night temperatures were then automatically manipulated to ensure that all of the treatments achieved similar mean diurnal temperatures. Plants were grown according to commercial practice and the experiment was repeated over 2 years. Increasing the day temperature from approx. 19°C to 21°C, and compensating by reducing the night temperature, did not have a significant impact on flowering time, although plant height was increased. This suggests that a temperature integration strategy which involves higher vent temperatures, and exploiting solar gain to give higher than normal day temperatures, should have minimal impact on crop scheduling. However, lowering the day-time temperature to approx. 16°C, and compensating with a warmer night, delayed flowering by up to 2 weeks. Therefore, a strategy whereby, in Winter, more heat is added at night under a thermally-efficient blackout screen may result in flowering delays. Transfers between the temperature regimes showed that the flowering delays were proportional to the amount of time spent in a low day-time temperature regime. Plants flowered at the same time, irrespective of whether they were transferred on a 1-, 2-, or 4-week cycle.     

The influence of temperature on photosynthesis of different tomato genotypes

Net photosynthesis and dark respiration from whole plants of various tomato genotypes were measured in a closed system. At low irradiance (27 W m^?2) and low external CO₂ concentration (550 mg m^?3), net photosynthesis of 10 genotypes was found to vary between 0.122 and 0.209 mg CO₂ m^?2 s^?1. Correlation was observed between net photosynthesis, net uptake on a daily basis (8 h photoperiod at 20°C and 16 h nyctoperiod at 10°C), specific leaf weight and leaf area ratio. At high irradiance (243 W m^?2), high external CO₂ concentration (1480 mg m^?3) and ambient temperatures of 10, 18, 20 and 26°C, four genotypes were analysed. ‘F6 I.V.T.’ had the highest rate of photosynthesis at 10°C, while ‘Sonatine’ ranked high at 26°C. Dark respiration increased with temperature, except in the case of ‘Bonabel’ where the effect of temperature was slight.     

荔枝常温保鲜初探

该文主要对pH，温度和湿度以及自行合成的涂膜保鲜剂对荔枝颜色稳定性及保鲜期的影响进行了研究，发现较低的温度和PH，较高的湿度是荔枝保鲜的必要条件，该试验研制的pH在3．5以下，含有抗菌剂，酶抑制剂的涂膜保鲜剂可显著延长荔枝在常温下的货架寿命。     

The effect of forcing temperature on peony shoot and flower development

Pre-chilled potted plants of Paeonia ‘Coral Sunset’, ‘Monsieur Jules Elie’, ‘Sarah Bernhardt’, and ‘Karl Rosenfeld’ were placed in a range of controlled temperature regimes to ascertain the effect of temperature on the timing of shoot emergence and floral development. For all cultivars, warmer temperatures up to 25 °C lead to more rapid shoot emergence and flower development. Linear temperature responses adequately described the rate of development from shoot emergence to flower bud appearance, and from bud appearance to flower opening, but a curvilinear response was required to describe the time taken for shoots to emerge. There were significant differences between cultivars in the number of heat units required for shoot emergence, with the shoots of the slowest-developing cultivar, ‘Monsieur Jules Elie’, taking 50% longer to emerge than those of the most rapid, ‘Coral Sunset’. No significant differences were found among cultivars in the time taken from shoot emergence to flower opening, although the ‘split’ stage (when the bud opens sufficiently for petal colour to be observed) was slightly earlier in ‘Karl Rosenfeld’.     

The morphological development of cauliflower and broccoli cultivars depending on temperature

In growth chambers the effect of temperature (12–27°C) on the growth and development of cauliflower cultivars of temperate and tropical climates, as well as of broccoli cultivars, was tested. No difference was found between the cultivars as regards dry matter production and curd growth, but a difference was found in the time of curd initiation. The early cauliflower ‘Aristokrat’ does not form lateral shoots or floral buds before elongation of the inflorescence at any temperature level. This always occurs in broccoli cultivars. The tropical cauliflowers have an intermediate position. At low temperatures (12–17°C) only 12–14 leaves are formed. Many lateral shoots are initiated and a broccoli-like curd with fertile flowers is developed. At high temperatures (22–27°C) the same cultivars produce a considerably higher leaf weight, less lateral shoots are initiated, and a cauliflower-like curd without floral buds is formed.     

The effect of temperature on axillary bud-break of hybrid tea-rose seedlings

The effect of temperature on the time of bud-break and on the number of sprouted buds was studied in F₁-seedling populations of glasshouse rose cultivars, which were grown in full daylight at 4 controlled temperatures (10, 14, 18 or 22°C). At lower temperatures, anthesis and bud-break occurred later. Relative to anthesis, bud-break occurred earlier with lower temperatures. Temperature had no effect on the percentage of buds sprouted, on the axillary position at which sprouting occurred, or on the order of sprouting. However, axillary buds in the central part of the seedling shoot were strongly inhibited; lower and upper buds sprouted almost simultaneously. Selection for time of sprouting and number of sprouted buds may be carried out at any temperature in the range studied.Differences in axillary bud-break between seedlings and cultivars, and the consequences for selection, are discussed.     

The effect of constant and alternating temperatures,rinsing, stratification and fertilizer on germination of some weed species

The effect of constant and alternating temperatures, rinsing, stratification and application of a fertilizer solution on germination of 4 weed species was studied.The seeds of Matricaria chamomilla L. (mayweed) and Poa annua L. (annual meadow grass) achieved almost 100% germination under any condition. For Solanum nigrum L. (black nightshade) an alternating temperature was necessary for germination. The germination percentage of this species was also improved by a cold pretreatment. For Thlaspi arvense L. (stinkweed) a high germination percentage was obtained only when stratification, alternating temperature and a fertilizer solution were applied.     

Purification of an anti-HBsAg scFv and measurement of its affinity constant

AIM: To purify and refold the inclusion body of a human anti-HBsAg scFv with a 6×His tag, and to determine the affinity constant of the purified recombinant product.METHODS: Solubilizing in buffers containing urea or guanidine hydrochloride(GuHCl), the inclusion body was purified by IMAC, and then refolded by dialysis against urea or GuHCl, at the same time, Ni²⁺ charged chelate column was utilized for in situ refolding. The affinity constant of the refolded scFv, polished by immune-affinity chromatography, was determined by non-competitive ELISA. RESULTS: The refolded scFv with highest specific bioactivity was produced by dialysis against GuHCl. Under this condition, the recovery of target protein reached(61.08±1.45)%. The affinity constant of the polished scFv was confirmed to be(2.30±0.32) ×10⁷ L/mol. CONCLUSION: The inclusion body studied in this paper can be refolded efficiently under optimal dialysis condition in vitro. The antigen-binding property of this recombinant scFv is not affected by the purification tag fused to the N terminal of the protein.     

柑橘小实蝇生物学特性与温度的关系

为有效控制柑橘小实蝇的发生、蔓延和危害,通过对其2009～2010年室外饲养观察,结果表明:柑橘小实蝇生物学特性与温度有着十分密切的关系,温度不仅对雌虫产卵前期长短和产卵所需时间有明显影响,而且当平均温度在20.3～29.9℃之间时,成虫交配初见至终见期随温度升高而延长;在不同的温度时段成虫产卵期和每只产卵粒不同;幼虫历期随着温度升高而天数缩短;成虫对低温敏感度不高;在本市不能越冬;随着温度的升高羽化率降低等结论。这将对柑橘小实蝇防控技术研究、预测预报提供科学依据,从而确保衢州市柑橘安全生产和农村稳定。     

The effect of temperature and humidity on the ripening of durian fruits

Summary

Fruits of ‘Chanee’ durian (Durio zibethinus Murr.) were exposed to temperature of 30°C and 33°C under low (70%) and high (90%) humidity. Typical climacteric patterns were recorded under each of the tested conditions, but at 33°C and 70% relative humidity (r.h.), low amounts of carbon dioxide and ethylene were produced. Fruits held at 30°C and 70% r.h., and at 33°C at both 70% and 90% r.h. ripened to full eating quality with a good pulp colour during the four-day exposure, while fruits held at 30°C at 90% r.h. did not. Fruits held at 33°C at 70% r.h. had the greatest total sugars, weight loss and dehiscence.     

Seed germination of seven pepper cultivars at constant or alternating high temperatures

Summary

Seeds of seven pepper (Capsicum annuum L.) cultivars (Anaheim TMR 23, California Wonder 300, Coronado, Jalapeno M, Ma Belle, Mercury, and Yolo Wonder B) were germinated at constant day and night temperatures of 25,30,35 and 40°C or at alternating temperatures of 40/25,40/30 and 40/35°C for 14 days. Germination percentages and rates were similar at 25 and 30°C. Largest differences in cultivar responses occurred at 35°C where germination percentages ranged from 24 to 96%, and rates, calculated as summation of the number of seeds germinated on a given day divided by day number, varied from 3 to 26 (theoretical maximum value of 100). At 40°C, germination percentages were less than 5% and rates were less than one for all cultivars. Cultivars with the most heat tolerance were ‘Mercury’ and ‘Yolo Wonder B’. At alternating temperatures, germination percentages and rates were higher than those at constant 40°C. The increases were greatest when the temperature was lowered by 15°C (40/25°C) and least when temperatures were lowered by 5°C (40/35°C). Tetrazolium tests showed that a large percentage of the ungerminated seed was still viable from the highest temperature. At lower temperatures, fewer ungerminated seeds were viable with no viable ungerminated seeds from the lowest temperature.     

The effect of temperature on growth and dry matter production of lychee seedlings

In lychee (Litchi chinensis Sonn.), high day/night temperatures ($\text{30}\text{25}$, $\text{25}\text{20}$, $\text{20}\text{15}\text{°}\text{C}$ compared to $\text{15}\text{10}\text{°}\text{C}$) increased stem extension, node and leaf production and plant dry weight in seedling selections of 6 cultivars (‘Bengal’, ‘Haak Yip’, ‘Kwai May’, ‘Gee Kee’, ‘Tai So’ and ‘Wai Chee’). The mean daily base temperature for shoot growth (node production) was estimated by linear correlation to be 11.0°C for the seedlings. High temperatures also increased the proportion of leaf and decreased the proportion of root in the total dry weight. There was a strong effect of cultivar on all aspects of growth, but the responses to temperature were similar.This experiment shows that temperatures in many tropical and warm sub-tropical areas where lychees are grown are too high to induce satisfactory vegetative dormancy prior to floral initiation. The assessment of lychee seedlings for low vigour in a heated glasshouse appears to be a useful technique for the initial screening of adapted genotypes (which flower and fruit under warm conditions) prior to field evaluation.     

Effect of storage temperature on apple volatiles associated with low temperature breakdown

Jonathan apples were stored at temperatures from —1° to 10 °C, and the rate of loss of volatiles from the fruit and the amounts of volatiles remaining in the fruit were measured over a period of 12 weeks.

Fruit stored at —1 °C retained the greatest amount of acetic acid. At 0° and 2.5 °C the amount retained was also high, but at 5° and 10 °C it was very low. The loss of butyl, isopentyl and hexyl acetates was highest at 10 °C and decreased markedly with decreasing temperature.

It is suggested that low temperature breakdown does not occur at higher temperatures because the increased loss of acetate as esters results in a reduction of the amount of acetic acid available to produce the disorder.     

The effect of temperature on sensory quality,chemical composition and growth of carrots (Daucus carota L.). III. Different diurnal temperature amplitudes

Summary

Data from experiments with carrots grown in phytotrons under different day and night temperatures at two locations in Norway and three harvesting dates were treated by means of Principal Component Analysis (PCA). No effect of the single temperature amplitudes were found, the significant main effects were due to the mean temperature levels of 12 and 188C, location and harvest date. The PCA visualized the effect of mean temperature level on sensory, chemical and physical variables. Differences between the two groups were mainly caused by variation in sensory variables, the first group being characterized by high score for whiteness, sweetness, acidic taste, crispness, juiciness, glucose, fructose and root length. The other group had a high score for colour, odour, overall taste and flavour parameters, firmness, dry matter, sucrose, a and b-carotene, root weight and root diameters.     

The influence of temperature,daylength and calendar date on cold tolerance of Rhododendron

Summary

Physical factors changing the acclimation and deacclimation processes that lead to cold (frost) tolerance and susceptibility in Rhododendron cv. Hatsurgiri are reported. Interactions between photoperiod and temperature which encouraged acclimation were studied by exposing detached leaves 0°C to –10°C, and assessing resulting injury using ion efflux and visual scoring. Combinations of short days (8 h) and exposure to 5°C resulted in the greatest cold tolerance. Exposure to long days (18 h) or 20°C reduced the cold tolerance of leaves. Application of each environmental factor, separately, increased cold tolerance compared with control tissues. When photoperiods were maintained at 12 h, exposing leaves to 5°C during the dark period enhanced cold tolerance compared with a 20°C dark period. Continuous 5°C applied during both light and dark periods encouraged greatest cold tolerance. Deacclimation from the cold tolerant state was accelerated by both higher temperature and longer photoperiods, but temperature was predominantly the more significant factor. Application of short days combined with low temperatures significantly delayed deacclimation. But even in this environment cold tolerance decreased over time, possibly through the action of endogenous annual rhythms. Cold tolerance changed with calendar time even when external environmental conditions were maintained at constant values and plant morphology was apparently unchanged.     

Size of tuber propagule influences injury of 'Kennebec' potato plants by constant light

Chlorosis and necrotic spotting develop on the foliage of particular cultivars of potato (Solanum tuberosum L.) when grown under constant light. 'Kennebec', a cultivar severely injured by constant light when propagated from tissue-cultured plantlets, also was injured when plants were propagated from small tuber pieces (approximately 1 g). However, plants did not develop injury when propagated from large tuber pieces (approximately 100 g). Plants from large tuber pieces grew more rapidly than plants from small tuber pieces. The role of plant vigor and carbohydrate translocation in controlling injury development is discussed.     

金太阳杏塑膜大棚温湿度及果实成熟温度研究

为了更方便人工监控杏冬暖式塑膜大棚的温度和湿度,选择早晨7∶00～9∶00和午后12∶00～14∶00时两个时段进行旬平均温度、湿度的测定和计算,获得大棚管理期内各旬的适宜温度、湿度指标和温度调控范围。在正常生长结果情况下,1月下旬花期阶段,早晨7∶00～9∶00时段温度达到9.2℃左右为宜,午后12∶00～14∶00时段温度以22.4℃左右为宜、最高不超过25.0℃;金太阳杏果实发育期早晨时段棚内旬平均温度积温值938.8℃作为预测大棚杏成熟的温度指标可行。1月至4月上旬各旬早晨时段棚内空气相对湿度56.5%～76.3%可做为调控指标。