Effect of dry and wet storage at cool temperatures on the post-harvest performance of Ranunculus asiaticus L. flowers

A study was undertaken to assess the effect of different storage temperatures on senescence and postharvest performance of isolated flowers of Ranunculus asiaticus L.. The main aim of the work was to develop a cost-effective storage protocol to reduce the postharvest losses and to bring out the transportation of cut flowers of R. Asiaticus. The flowers were subjected to two different storage treatments, dry storage and wet storage, and their postharvest performance was compared under laboratory conditions. For this purpose, the buds were harvested at 8:00 AM at loose bud stage (Stage II of flower development). The harvested buds were cut to a uniform size of 15 cm and processed for dry or wet storage. For dry storage, the buds were packed after wrapping them in moistened filter papers and kept at 5°C and 10°C. For wet storage, the buds were held in distilled water in separate glass beakers kept at 5°C and 10°C, respectively. A separate set of buds each for dry and wet storage was kept at room temperature (15±2)°C. After 72 h storage, the buds were kept at room temperature in distilled water. The average life of an individual flower that opened fully was about 4–5 days. The buds kept under wet storage at 5°C and 10°C for 72 h maintained their premature status, while the buds held at room temperature for 72 h generally bloomed. All the buds stored dry maintained their premature status irrespective of storage temperature. Storage of buds for 72 h at 5°C, followed by transferring to distilled water improved the longevity by about 5 to 6 days. Cold storage treatment before transferring to holding solution improved floral diameter, membrane integrity besides maintaining higher fresh and dry mass of flowers, sugar content, soluble proteins, and phenols. Our results suggested that wet and dry storage of premature buds of R. asiaticus for 72 h at 5°C, followed by placing them in distilled water, improved the cut flower longevity and can be used as effective postharvest storage treatments for this beautiful cut flower.     

Wheat Generation Adding in Xundian County of Yunnan Province in Summer

Local climate conditions and sowing time are very important to the vernalization and summer reproduction of the wheat. Xundian County is located in Yunnan Province of China, at latitude 25.56° north and longitude 103.25° east. Xundian County is situated 1 873 m above sea level, and is conducive for the summer reproduction of the wheat. To investigate the optimal sowing time, 11 spring wheat cultivars and one semi-winter wheat cultivar were sown 10 times at an interval of fi ve days from May 26, 2012, and the strong winter wheat Suyin 10 was treated in a vernalization room at 2℃ with different concentrations of the gibberellin and 5-azacytidine. The results showed that Suyin 10 should be vernalized at 2℃ for 30 days in summer, and the growth periods of strong winter wheat plants could been shortened if treated with a specifi c concentration of the gibberellin and 5-azacytidine at a low temperature. The growth period of the spring wheat in summer reproduction was delayed, and their agronomic traits gradually decreased with the passage of the sowing time. Thus, spring wheat should be sown at the earliest time possible for better yield. June 25 should be the latest date for summer reproduction of the wheat, but the semi-winter wheat cultivars in Xundian County should be added generation in summer after being treated at 2℃ for 10 days. Xundian County is a suitable location for summer reproduction of the wheat in China.     

High temperatures do not decrease biocontrol potential for the host-killing parasitoid Neochrysocharis formosa (Hymenoptera: Eulophidae) on agromyzid leafminers

Temperature, as a critical abiotic factor, might influence the effectiveness of biological control by parasitoids in host-parasitoid systems. In this study, Neochrysocharis formosa (Westwood), a larval endoparasitoid, is used to investigate the efficacy of biological control on a vegetable agriculture pest, Liriomyza sativae Blanchard, reared on kidney bean (Phaseolus vulgaris L.), at four constant temperatures (26, 29, 32, and 35°C) under laboratory conditions. Our results show that high temperatures (29, 32, and 35°C) do not significantly affect lifetime host-killing events of female adults by increased daily host-killing events compared to temperature of 26°C, although their lifespans decrease with an increase in temperatures. Each life-history trait of female adults (lifespan, parasitism, stinging, or non-reproductive host-killing events) present a linear relation with temperatures and host-feeding events, respectively. Our findings contribute to a better understanding of biocontrol efficacy of parasitoid N. formosa against agromyzid leafminers at high-temperature seasons or environments.     

Effects of Environmental Temperature on the Regeneration Frequency of the Immature Embryos of Wheat （Trificum aestivum L.）

The immature embryos （IEs） of wheat are the most widely used tissues for in vitro culture and genetic transformation due to its high regeneration competency. However, this explant can only be maintained in 4℃ daily cooler for a short period time for its use in plant tissue culture or transformation experiments. This study aimed to investigate the effects of environmental temperature, cryopreservation storage temperature, and heat shock culture （HSC） temperature on the regeneration frequency of wheat IEs. Results indicated that environmental temperature significantly affected the induction of embryonic calli. The optimum total accumulated temperature （TAT） during the time of anthesis and sampling for regeneration of these tissues was around 280℃ for spring wheat type cv. CB037 and approximately 300℃ for winter wheat type cv. Kenong 199. Regeneration ability obviously declined when the highest environmental temperature was over 35℃ for 1 d or a high temperature between 30 and 33℃ lasted for 5 d during anthesis and sampling. This finding was verified by culturing the freshly isolated IEs under different temperatures from 29 to 37℃ in different controlled growth incubators for 5 d; the IEs almost completely lost regeneration ability when the temperature rose to 37℃. Cryopreservation of-20℃ caused the wheat samples lost ability of producing callus or embryonic callus in a few days, and cryopreservation of-10℃ more than 10 d made the regeneration potential of the tissues dramatically declined. Comparatively, the temperature that best maintained high regeneration ability was -5℃, at which the materials can be maintained for around 1 mon. In addition, the preservation of the immature samples at -5 or -10℃ inhibited the direct germination of the IEs, avoiding the embryo axis removing process. Our results are useful for ensuring that field collection and cryopreservation of the wheat IEs are done correctly to enable tissue culture and genetic transformation.     

Effects of constant and stage-specific-alternating temperature on the survival,development and reproduction of the oriental armyworm,Mythimna separata (Walker) (Lepidoptera: Noctuidae)

Migratory insects make diverse adaptive strategies in response to changes in external environment. Temperature has an impact on the survival, development, reproduction, and migration initiation of insects. Previous research has primarily been focused on the effects of constant temperature on populations, but changing temperature has received less attention. Three constant temperature treatments(20, 25 and 30°C) and three pupal-alternating temperature treatments(20–25, 25–20 and 25–30°C) were set up to study the relationship between temperature and population development by age-stage, two-sex life table analysis in the oriental armyworm, Mythimna separata Walker, a notorious migratory pest in grain crops. The 25°C treatment was considered optimal with 20 and 30°C as low suitable temperature and high temperatures, respectively. The survival rate was relatively low before third instar larvae at 20°C(63.0%) and 20–25°C(70.1%), and extreme low after pupal stage at 30°C(20.6%). Developmental duration of each stage was negatively correlated with temperature. The adult preoviposition period, when most migratory insects initiate migration, was the shortest at 25°C(2.69d) but was lengthened at both low suitable(7.48d for 20°C, 6.91d for 25–20°C and 4.57d for 20–25°C) and high temperatures(3.74d for 25–30°C and 5.00d for 30°C). Both low suitable and high temperature decreased lifetime fecundity, net reproductive rate and the intrinsic rate of increase, with variability observed across developmental duration and stage during non-optimal temperature. The results expand knowledge of the relationship between changing temperature and armyworm population development, and adaptive strategies in complex ambient environment.     

电导法结合Logistic方程对6个文冠果种质抗寒性的评价

为了评价引进文冠果种质的抗寒性,为其进一步栽培和育种利用提供参考,以引进种质6份文冠果种质((G27、BD12、BD特异、建2、株系2、G13))为试材,设置-10 °C、-20 °C、-30 °C低温胁迫梯度,测定相对电导率,并拟合Logistic方程计算半致死温度(LT50),评价供试种质抗寒性强弱。结果显示供试种质半致死温度分别是-13.272、-12.244、-11.543、-8.246、-5.643、-2.642 ℃,依据半致死温度评价抗寒性强弱为BD特异>G27>BD12>建2>G13>株系2。相对电导率结合Logistic方程评价文冠果种质抗寒性结果与前期研究结果基本一致,可作为评价种质抗寒性的简要方法之一,同时为引进种质进一步在新疆地区栽培与育种利用提供参考。     

Effects of Dietary Protein and Temperature on Growth and Flesh Quality of Songpu Mirror Carp

The study was conducted to demonstrate the effects of dietary protein and water temperature on growth and flesh quality of Songpu mirror carp （Cyprinus carpio） at an initial weight （165.24±5.08） g. Practical diets were formulated to contain five protein levels （29.12%, 31.46%, 34.49%, 38.17%, and 40.13%）, and each diet was randomly assigned triplicate groups of 15 fishes at three temperatures （18℃, 22℃, and 26℃） in the recirculation system. Fishes were fed twice daily to apparent satiation for 56 days. Results indicated that fishes had higher weight gain rate at 22℃ and 26℃ than that at 18℃ （P〈0.05）, but there were no significant differences between 22℃ and 26℃ （P〉0.05）. Based on the weight gain rate, dietary protein level 29.12% could meet the requirement of the body at 18℃, 22℃, or 26℃. Crude protein, crude lipid, moisture and ash of muscle had no significant differences among those treatments （P〉0.05）. pH （after 24 h） of muscle was the highest at 18℃ and the lowest at 22℃ （P〈0.05）, but no differences were observed among different protein level groups at each temperature （P〉0.05）. No significant differences on shear force, water holding capacity, collagen, glycogen and lactate among all the treatments were found （P〉0.05）. It was concluded that when C. carpio fed to apparent satiation, the growth mainly depended upon temperature. Dietary protein could not significantly affect flesh quality, but temperature significantly affected pH of muscles. A dietary protein level 29.12% could meet the requirement of the body at 18℃, 22℃, or 26℃.     

Optimal storage temperature and 1-MCP treatment combinations for different marketing times of Korla Xiang pears

Maintenance of green color is the primary indicator of quality in the market evaluation of Korla Xiang pears at present and can generally be achieved through early harvesting and decreasing the storage temperature, but the fruit quality was reduced by early harvesting, and the decreasing storage temperature increased the risk of chilling injury. The objectives of this study were to determine the optimal storage parameters for different storage times and to find ways to preserve the green skin color of pears. Specifically, we analyzed the effects of the ethylene inhibitor, 1-methylcyclopropene(1-MCP), combined with low temperature on quality and maintenance of the green color of Korla Xiang pears during storage. We found that 1-MCP and/or low temperature reduced the loss of green color at 20°C after being removed from cold storage. In addition, 1-MCP significantly inhibited the decline of titratable acid and ascorbic acid but had no significant effect on fruit firmness and total soluble solids. Low temperature with or without 1-MCP inhibited the release of ethylene, inhibited the decline in the stalk preservation index, inhibited the increase in decay rate and weight loss rate during storage, and inhibited the increase in the core browning index after 225 days of storage. Different storage temperatures had different effects on the quality of Korla Xiang pears. Despite inhibiting ethylene release, a storage temperature of –1.5°C increased the respiration rate. Storage at –1.5°C caused core browning early during storage due to chilling injury, whereas at 2°C core browning occurred late during storage due to senescence. In late storage, 1-MCP had no significant effect on the maintenance of Korla Xiang pear quality at 2°C. Based on these results, we determined the optimal combinations of low temperature and 1-MCP treatment to maintain pear quality while avoiding chilling injury. For different marketing times, the optimal conditions for storage until New Year's Day(a storage duration of 90 days) are 2°C or 1-MCP combined with 2°C. For storage until the Spring Festival(a storage duration of 150 days), the optimal conditions are 0°C or 1-MCP combined with 0°C, and for storage until May(a storage duration of 225 days), the best conditions are 1-MCP combined with –1.5°C.     

Effect of Water Temperature on Feeding Rhythm in Common Carp （ Cyprinus carpio haematopterus Temminck et Schlegel）

Feeding rhythm of common carp was investigated from 4°cC to 34°C. The results indicated that there was a diel feeding rhythm for both adult (630–850 g) and youth (61–91 g) at all tested temperatures. There were two main activity peaks at 8:00–11:00 a.m. and 19:00–23:00 p.m., during which feeding quantities were 10.68%–32.53% and 16.25%–33.41% of the daily intake, respectively. When water temperature dropped to below 10°C, the feeding peak concentrated at 8:00–11:00 a.m. and 19:00 p.m. to 4:00 a.m. At 6°C, though both adult and youth would still feed, the feeding quantities were only 0.01% and 0.35% of body mass. Daily feeding rate of adult and youth reached 1.21% and 2.63% at 14°C, respectively. Both adult and youth carps reached the maximum daily feeding rate at 28°C, being 2.84% and 12.06% of body mass, respectively. The daily feeding rate of adult and youth reduced suddenly after at 34°C, and the daily feeding rate was only 0.74% and 9.45% of body mass, respectively. There was significant difference in daily feeding rate at different water temperatures (P<0.05).     

Physiological activities and expression of insecticidal protein in Bacillus thuringiensis transgenic cotton leaves subjected to high and low temperatures

This research was to investigate physiological activities and the expression of insecticidal protein in cotton leaves of Kemian 1, a widely grown cotton cultivar in the lower reaches of the Yangtze River, treated under high (40°C and 35°C) and low (25°C and 20°C) temperatures for 48 h. The main results indicated that the contents of free amino acid and malondialdehyde (MDA) increased during the heat and cold stress with the biggest increments in the first 12 h; and the content of soluble protein, activities of superoxide dismutase (SOD), and glutamic-pyruvic transaminase (GPT) decreased during the stress with the biggest decrements also in the first 12 h; the activity of nitrate reductase (NR) decreased in the first 24 h, and during the remaining 24 h its activity followed a gradual uptrend. The content of insecticidal protein in cotton leaves followed a downtrend during the stress, and the biggest decrements occurred in the first 12 h, suggesting that the expression of insecticidal protein was immediately inhibited during the process of stress. The results also indicated that physiological activities and the expression of insecticidal protein in cotton leaves were closely related. Compared with other stress temperatures, 40°C produced more immediate effects on the physiological activities and insecticidal protein content. In contrast to the peak flowering period, the physiological activities and insecticidal protein expression at the peak boll-setting period were more susceptible to heat and cold stress.     

Forecasting upcoming weather conditions of vegetation and grain-crop yield in the dry-steppe zone of the pre-Ural Region

The long-term forecast of yield and vegetation conditions of grain crops for the dry-steppe zone of the pre-Ural Region is made for the first time based on new predictors and their time lags. The forecast is developed for the value of the predictant (Y) and all predictors (X) that are included in the multiple regression models. The obtained results permit the probability of the onset of drought in the expected year to be described in advance (5–6 months before the start of field works). The developed models indicate that a strong drought is expected for grain crops in 2017 (the winter wheat yield of 2–3 c grain/ha), which is due to unfavorable weather conditions in June (the precipitation of 3–4 mm) and high air temperature in July (the average temperature in the first decade of 25.2°C and maximum temperature of 37.5°C). This information makes it possible to choose the optimal technological solutions for overcoming the influence of unfavorable conditions. The methods of step-by-step multiple regression and neural network regression and the method of residual deviations in combination with the method of superposition of epochs are used.     

酸性电解水对低温条件下单增李斯特菌杀灭效果

单增李斯特菌是能在低温下生长的一种微生物。冷藏即食食品和冷冻食品加工设备中单增李斯特菌的生长是主要的食品安全问题。酸性电解水(AEW)是一种新型高效、安全且无残留的非热灭菌技术。AEW用于灭活4℃条件下的浮游态、生物膜态及冷藏金针菇样品上单增李斯特菌。通过检测AEW处理前后菌落总数变化、生物被膜、生物被膜结构参数以及毒力基因表达,进一步分析样品实验等。结果表明,当电解质NaCl浓度为0.10%,处理时间为1 min、30 min时,4℃和37℃下的单增李斯特菌菌落总数、生物被膜清除率存在极显著差异,相同处理时间,AEW较难杀灭4℃条件下的单增李斯特菌及难清除其生物被膜,本研究为评估冷链中食品和冷藏食品及食品加工设备的安全性提供了新的理论基础,对冷藏食品使用抗菌剂提出更高要求。     

Studies on isolated microspore embryoid induction of <Emphasis Type="Italic">C. annuum</Emphasis> L.

A system to improve isolated microspore embryoid induction rate of pepper (Capsicum annuum L.) was studied in this paper. The results showed that low-temperature pretreatment, growth regulators combinations, activated carbon concentrations, and preculture temperatures were critical factors affecting embryoid formation of isolated pepper microspores in vitro. One day after pretreatment of the buds at 4°C, the anthers that differentiated and developed into embryos were cultured in double-layer medium system for one week at 7°C and then went on culturing at 28°C in darkness. All the seven genotypes of the tested pepper responded to this protocol. The embryoid induction rate of the best genotype increased from 81.11% to 147.22%. This protocol can be used as a potential tool for producing doubled haploid plants for pepper breeding.     

Characterization of T-complex polypeptide 1 (TCP-1) from the Chilo suppressalis HSP60 family and its expression in response to temperature stress

Many proteins require assistance from molecular chaperones at various stages to attain correctly folded states and functional conformations during protein synthesis. In this study, the gene encoding T-complex polypeptide 1(TCP-1), which belongs to the heat shock protein 60(HSP60) family, was isolated and characterized from the rice stem borer, Chilo suppressalis, by RACE and q PCR, respectively. The full-length c DNA of Tcp-1 was 2 144 bp and encoded a 1 635-bp ORF; the deduced translational product contained 545 amino acids with 5′-and 3′-UTRs and an isoelectric point of 5.29. Cluster analysis confirmed that the deduced amino acid sequence shared high identity(60–99%) with TCP-1 from other insects. To investigate Tcp-1 expression in response to abiotic stress, q PCR was used to analyze expression levels of Tcp-1 m RNA in C. suppressalis larvae exposed to temperatures ranging from –11 to 43°C. With respect to heat shock, Tcp-1 expression was higher than the control after a 2-h exposure to 30 and 36°C and declined at 39 and 43°C. Difference in Tcp-1 expression was observed at temperatures ranging from –11 to 27°C. q PCR analyses revealed that Tcp-1 expression was the highest in hindgut tissue as compared to heads, epidermis, fat body, foregut, midgut, and malpighian tubules. Our results indicated that Tcp-1 expression was differentially expressed in C. suppressalis tissues, and was impacted by temperature stress.     

Optimization of rhizosphere cooling airflow for microclimate regulation and its effects on lettuce growth in plant factory

In plant factories, the plant microclimate is affected by the control system, plant physiological activities and aerodynamic characteristics of leaves, which often leads to poor ventilation uniformity, suboptimal environmental conditions and inefficient air conditioning. In this study, interlayer cool airflow(ILCA) was used to introduce room air into plants' internal canopy through vent holes in cultivation boards and air layer between cultivation boards and nutrient solution surface(interlayer). By using optimal operating parameters at a room temperature of 28℃, the ILCA system achieved similar cooling effects in the absence of a conventional air conditioning system and achieved an energy saving of 50.8% while bringing about positive microclimate change in the interlayer and nutrient solution. This resulted in significantly reduced root growth by 41.7% without a negative influence on lettuce crop yield. Future development in this precise microclimate control method is predicted to replace the conventional cooling(air conditioning) systems for crop production in plant factories.     

Effect of various combinations of temperature during different phenological periods on indica rice yield and quality in the Yangtze River Basin in China

Rice grain yield and quality declines are due to unsuitable temperatures from wide regions and various sowing dates.This study aimed to evaluate the effects of temperature on rice yield and quality at different phenological periods and obtain suitable temperatures for phenological periods in the Yangtze River Basin,China.This study conducted experiments on different sowing dates under different areas in the Yangtze River Basin to observe and compare the differences in rice growth,yield,and quali...     

不同储存条件对蔬菜中Vc含量的影响

研究了不同储存条件（室温、冰箱4℃冷藏、保鲜膜冷藏和保鲜盒冷藏）和储存时间下白菜、黄瓜、芸豆和冬瓜Vc含量的变化。结果表明：无论是在室温还是在低温条件下,4种蔬菜中Vc含量均随储存时间的延长而减少;在相同的储存时间,低温条件下储存的蔬菜中Vc含量及其变化速率均明显低于室温条件下;3种低温处理,Vc的含量损失从小到大的顺序是保鲜盒冷藏、保鲜膜冷藏和冷藏：蔬菜中Vc含量及变化速率因蔬菜品种不同而存在显著差异。     

Assessing the effect of temperature stressors on maize plants from the change in antioxidative activity

The effect of low (3°C) and high (44°C) temperatures on stress indices in young maize plants is examined. Unfavorable temperatures cause inhibition of the growth of axial organs, intensification of lipid peroxidation, and reduction of antioxidant activity, from the degree of suppression of which the intensity of the stress effect of abiotic factors on plants can be judged.     

Role of TRP channels and HSPs in thermal stress response in the aphid parasitoid Aphelinus asychis(Hymenoptera:Aphelinidae)

Aphelinus asychis is an important aphid endoparasitoid. Under field and greenhouse conditions, high temperature is one of the factors limiting the application of A. asychis for biological pest control. To explore the potential role of transient receptor potential(TRP) channels and heat shock proteins(HSPs) in this process, we identified 11 genes encoding TRP channels and nine genes encoding HSPs. Three proteins(AasyTRPA5, AasyPyrexia, AasyPainless) that belong to transient receptor potential ankyrin(TRPA) subfamily and nine HSPs are involved in the response to high temperature. We also investigated the survival of A. asychis and the response of the identified TRP channels and HSPs to high temperature. The results showed that the maximum temperature that allowed A. asychis survival was approximately 41℃; females had higher survival rates than that of the males at 40 and 41℃. Short-term heat-shock resulted in increased expression of Aasyshsp in males, and Aasyhsp40, Aasyhsp68, Aasyhsp70-4, Aasyhsp70-5 and Aasyhsp90 were upregulated and then downregulated, whereas Aasyhsp70-3 was upregulated at 41℃. Moreover, Aasyhsp40 and Aasyhsp90 showed higher expression levels in females, while Aasyshsp and Aasyhsp70-3 presented opposite expression patterns. At temperature above 35℃, expression of AasyPyrexia in females was significant higher than that in males, whereas AasyPainless and AasyTRPA5 presented higher expression in males at 40 and 41℃, respectively. Altogether, these results indicate that protection against thermal stress in A. asychis is coordinated by TRP channels and HSPs. These findings provide a basis for understanding the potential mechanism of A. asychis in response to high temperatures.     

European seasonal and annual temperature variability, trends, and extremes since 1500

Multiproxy reconstructions of monthly and seasonal surface temperature fields for Europe back to 1500 show that the late 20th- and early 21st-century European climate is very likely (>95% confidence level) warmer than that of any time during the past 500 years. This agrees with findings for the entire Northern Hemisphere. European winter average temperatures during the period 1500 to 1900 were reduced by approximately 0.5 degrees C (0.25 degrees C for annual mean temperatures) compared to the 20th century. Summer temperatures did not experience systematic century-scale cooling relative to present conditions. The coldest European winter was 1708/1709; 2003 was by far the hottest summer.