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1.
将中豆24和泰兴黑豆种子用无水CaCl2分别干燥至10个不同的含水量水平,密封于玻璃瓶中分别在25度培养间,5度冰箱中保存一年中,对种子生活力和活力进行测定,结果表明,中豆24在25度,5度条件下保存的最佳含水量为6.0%,泰兴黑豆在25度条件下保存的最佳含水量为5.4%,在5度下保存的最佳含水量为6.0%。  相似文献   

2.
芝麻种子超干贮藏研究   总被引:5,自引:1,他引:5  
选用豫芝四号种子为材料,将不同含水量的种子分别密封在室温(20-25℃)和低温(5℃)下贮藏12个月,在室内水分平衡后测定种子的生活力和活力,结果表明,室温下适当干燥能使芝麻种子保持较高活力水平,种子含水量存在一个超干水平临界值,室温贮藏时为3.78%,低温贮藏时为6.01%。  相似文献   

3.
中豆24和泰兴黑豆种子用无水CaCl2分别干燥至10个不同的含水量水平,密封于玻璃瓶中,在50℃人工模拟老化条件下3个月后,对种子活力和生理特性的测定结果表明,中豆24和泰兴黑豆均适宜于超干燥保存,超干燥能明显延长种子寿命,50℃人工模拟老化条件下超干燥保存的最佳水分含量,中豆24为4.2%,泰兴黑豆为3.4%。  相似文献   

4.
通过不同的预处理、预湿方式及时间、四唑溶液浓度及染色时间的试验,摸索出四唑染色测定红麻种子生活力的最佳方法:种子缓慢预湿12小时后剥去种皮,用0.5%四唑液于35℃下染色3-4小时。  相似文献   

5.
本文研究不同温度、不同pH条件下右旋糖酐酶的保存稳定性,并尝试加入防腐剂和稳定剂达到右旋糖酐酶酶液在常温下长期保存的目的。实验结果表明:①右旋糖酐酶在pH5.5时,温度为4—25℃下保存150h,相对酶活仍有90%以上;但当贮存温度超过30℃后,酶活在较短时间明显下降,且温度越高,酶活下降速度越快。②右旋糖酐酶在pH4—6,温度为4℃下保存一周,相对酶活仍有80%以上。③右旋糖酐酶液中添加甘油浓度达到30%时,室温下保存56天后,相对酶活仍有80%以上。  相似文献   

6.
贮藏于密封干燥器中的油菜种子活力、田间植株生长发育节律和形态及农艺性状的研究结果表明,保存时间超过11a,种子含水量可降至4%以下。于燥器中保存11a的种子产生的变异为可逆的生理性变化,保存时间超过18a则发生不可逆的遗传性劣变。初步确认利用密封干燥器和适宜干燥剂能安全保存油菜种子10a左右。  相似文献   

7.
茶叶文萃     
产出茶昆虫──米缟螟存活繁殖及产茶适宜温湿度范围的研究用三叶海棠饲养米镐螟(俗名米黑虫AglossadimidataH)取其排泄物作饮料(虫茶)。在温度为25-30℃,湿度为55%-95%条件下,大部分米缟螟卵能够正常孵化,但在35℃温度下,孵化率为0,实验数据推导出的有效回归方程推导米缟螟卵的致死高温(35.9℃),亚致死高温(31.3℃)和最适温(26.7℃)。幼虫成活率,在32℃下,全期成活率仅为24.0%,35℃下仅8.0%,在55%相对湿度下,不管温度多少,全期存活率无均为0。产虫茶量最佳湿度为87.3%,略低于各龄幼虫存活所要求最佳…  相似文献   

8.
以发芽率为指标,研究了40份甘蓝型、白菜型和芥菜型油菜在-20℃、4℃、25℃、37℃、60℃温度储藏3个月、6个月、12个月后种子生活力的变化。结果显示:-20℃和4℃储藏下,不同基因型间种子发芽率变异较小,而25℃、37℃和60℃储藏下,基因型间种子生活力存在明显差异,选择60℃高温储藏不同时间的种子进行生活力鉴定,从甘蓝型、白菜型和芥菜型油菜中均筛选得到耐储藏的基因型。  相似文献   

9.
水稻种子在不同气候区室温贮藏的适宜含水量及存活特性   总被引:1,自引:0,他引:1  
 将不同含水量水平的两个水稻品种幸实(粳稻)和桂朝2号(籼稻)分别贮藏在三亚、南昌、北京、西宁、乌鲁木齐和哈尔滨等6个不同气候类型地区。通过11年的逐年生活力测定,研究了水稻种子室温贮藏的适宜含水量及其存活特性。结果表明,水稻种子经适当干燥后其生活力和活力没有显著下降。但当种子含水量在30%以下时种子的生活力和活力受到影响。获得了水稻种子在三亚、南昌室温贮藏时(贮藏温度不是恒定的)的适宜含水量,且适宜含水量50%~65%具有地域的广适性。相对于其他含水量,适宜含水量种子在贮藏过程中,其生活力快速下降阶段推迟,且适宜含水量上限和极差与贮藏地点年均温和≥0℃积温呈显著或极显著负相关,且适宜含水量下限与之呈显著或极显著正相关。种子在年均温度相同的西宁和乌鲁木齐的贮藏效果不同,≥0℃积温和气候温差波动的差值可能是其主要影响因素。  相似文献   

10.
普通人参种子长期保存技术研究初报   总被引:2,自引:0,他引:2  
人参种子经过干燥,含水量降至3.0%和4.9%,TTC法染色率为100%,脱氢酶活性略有升高。含水量7.8% ̄3.0%的种子在-196℃保存近1年后,种子生活力平均为90%,经过后熟处理,种子裂口率和田间出苗率同对照没有明显差异,形态发育和苗期生长正常。说明人参种子能忍耐干燥和低温,属正常型种子范畴。  相似文献   

11.
12.
Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.  相似文献   

13.
Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.  相似文献   

14.
15.
Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.  相似文献   

16.
Novel food and non-food uses for sorghum and millets   总被引:4,自引:3,他引:4  
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.  相似文献   

17.
Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.  相似文献   

18.
Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X1 (also called RXact).  相似文献   

19.
The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O2•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O2•− scavenging, (IC50 = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC25 = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC50 = 863 µg/mL; elastase, IC50 = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O2•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.  相似文献   

20.
The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.  相似文献   

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