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1.
在实验室的条件下,分别对灰叶豆种子的硬实率、吸水曲线、发芽势与发芽率等萌发特性进行测定,结果表明:灰叶豆种子的硬实率较高,平均硬实率达72%;种子吸水曲线呈现“快-慢-稳”的格局;种子发芽时间较为集中,在置床第二天开始萌发,第三天达到高峰,第四天后很少或几乎不发芽,各处理方法中,以浓硫酸处理15 min和80℃浸泡5 min的发芽率和发芽势较高,分别达到84.3%、67.7%和80.0%、61.0%。  相似文献   

2.
采用浓硫酸对木豆种子进行不同浸泡时间的催芽处理,测定种子的发芽率、发芽势和发芽指数,分析不同时间处理、温度、种质采集高度及种子千粒重对木豆种子萌发的影响。结果表明:木豆种子用浓硫酸浸种处理的最佳时间为1 min,发芽率达92.33 %。木豆种子发芽的最适温度为25℃。大部分木豆种子的千粒重较重,发芽率也相对较高。  相似文献   

3.
通过GA、乙烯利和温水等不同措施对普通油茶种子进行预处理.测定普通油茶种子发芽率和平均发芽时间.结果表明:GA和温水处理能提高种子发芽率和缩短平均发芽时间.其中以0.1%GA处理种子2h发芽率最高。达到72%;始温60℃温水处理种子48h平均发芽时间最短.为17.9d;乙烯利处理会降低种子发芽率和延长平均发芽时间。  相似文献   

4.
用KMNO_4和H_2O_2两种化学试剂分别对常温密闭保存的水稻新种、1年陈种、2年陈种进行浸泡处理,以纯净水浸泡作对照,研究分析不同化学试剂的不同浓度对3类种子发芽率及成苗率的影响。结果表明,随着种子存放时间的延长,种子的发芽势、发芽率和成苗率均呈下降趋势;所有试剂处理后的种子发芽势、发芽率以及成苗率均高于对照,差异显著;新种处理中以5%浓度的H_2O_2处理后的种子发芽率最高,为95%,质量比为1∶2 000的KMNO_4处理后的种子成苗率最高;1年、2年陈种处理中的最高发芽率和最高成苗率均为KMNO_41∶2 000处理。  相似文献   

5.
大叶千斤拔是一种具有饲用及药用价值的豆科植物,种子育苗发芽率低,不能满足人工栽培需要。通过不同化学处理试验结果:经浓硫酸浸泡10min的处理其发芽率、发芽势、发芽指数为最高,依次为92.0%、92.0%,148.38,此方法可用于大叶千金拔育苗种子的处理。  相似文献   

6.
通过对市场上常见的几种种衣剂进行对比试验,结果表明,使用种衣剂包衣对种子发芽、长势、病害防治均有很好的效果,优于常规处理,其中稻吉吉种衣剂处理的发芽势和发芽率均优于对照和常规处理,发芽势和发芽率分别可达到98%和96.5%;秧苗素质方面稻吉吉种衣剂处理各项指标均表现最高,其中干物质积累和茎基宽量分别高31.58%和16.3%。  相似文献   

7.
为了测定不同浓度富里酸(FA)和腐植酸(HA)对甜菜种子的引发效果,为甜菜种子包衣剂物料的筛选提供依据。以不同浓度富里酸(FA)、腐植酸(HA)及两者组合为处理试剂,干种子为对照,通过对‘STm1616’甜菜种子浸泡回干发芽培养,测定其发芽势、发芽率、发芽指数和活力指数。结果表明,处理后甜菜种子的发芽势、发芽率、发芽指数和活力指数均得到了提高。与对照组相比,处理后种子的发芽势提高了3.34~10.34个百分点(平均6.96个百分点),发芽势最高的0.0375%FA+0.0375%HA比最低的0.05%FA高出7.00个百分点;处理后种子的发芽率比对照组提高了4.33~11.33个百分点(平均8.74个百分点),发芽率最高的0.0375%FA+0.0375%HA比最低的0.05%FA高出7.00个百分点;处理后的发芽指数比对照组提高了48.69%~142.89%(平均76.32%),发芽指数最高的处理0.075%HA比最低的处理0.25%FA+0.025%HA高63.35%;处理后的活力指数提高了100.62%~254.59%(平均147.42%),活力指数最高的0.075%HA比最低的...  相似文献   

8.
通过滤纸床发芽方法测定薜荔种子的发芽率、发芽势、发芽指数等指标,观察不同浸种时间、外源H 和K 以及用H 和K 协同处理对薜荔种子萌发的作用。结果表明:不同浸种时间对薜荔种子萌发影响不显著,外源H 和K 的处理对薜荔种子发芽促进作用明显。  相似文献   

9.
【目的】确定有效破除紫云英种子休眠的方法。[方法]采用机械破除、酸蚀和开水烫种方法处理紫云英种子,研究不同处理方法对紫云英种子发芽势和发芽率的影响。【结果]砂纸打磨处理的种子发芽势和发芽率最高,分别为75%和94%;采用36%浓度的盐酸处理9min,种子发芽势和发芽率分别为25%和52%;29%浓度的双氧水浸种和开水烫种处理的种子发芽率与对照差异不显著,破除效果均不明显。[结论]采用机械摩擦法破除紫云英种子休眠效果最好.  相似文献   

10.
为了提高菜用黄麻种子的发芽率,保证出苗的整齐度,采用沙子研磨、热水浸种、98%浓硫酸浸种和40%氢氧化钠浸种共4种方法对菜用黄麻桂麻菜1号和桂麻菜2号种子进行处理。结果表明:沙子研磨、热水浸种、98%浓硫酸浸种处理对种子的发芽势和发芽率均有显著地影响。桂麻菜1号和桂麻菜2号在种子与沙子体积比1:4、研磨时间为8 min时,种子发芽率最高分别为78.0%、86.3%;热水80℃浸种8 min时,种子发芽率最高分别为86.3%、83.0%;98%浓硫酸浸种处理30 min时,桂麻菜1号发芽率最高达78.3%,桂麻菜2号在浸种10 min时,发芽率最高达87.3%。40%氢氧化钠浸种处理对菜用黄麻种子发芽率的影响不明显。在这4种菜用黄麻种子处理方法中,热水浸种方法易于操作,处理时间短,成本低廉,适合生产上推广运用。  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.
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   

16.
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   

17.
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   

18.
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   

19.
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   

20.
Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).  相似文献   

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