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1.
钾水平对巴西橡胶树幼苗生长及体内N、P、K养分吸收利用的影响 总被引：1，自引：0，他引：1
采用水培试验技术,研究不同钾水平(K2O浓度0、1、10、50、250mg/L)对巴西橡胶树RRIM600种子实生幼苗生长及体内氮、磷、钾养分吸收和利用的影响。结果表明:在0～250mg/LK2O范围内,巴西橡胶树实生幼苗株高、根长、茎粗及各器官生物量等均随钾处理浓度的升高而增加;不同钾水平处理,巴西橡胶树幼苗各器官氮含量、氮利用效率不随钾浓度的升高而呈现规律的变化,但氮积累效率则随钾水平的升高而增加;施钾降低了巴西橡胶树幼苗各器官磷含量,而提高了不同器官磷积累效率和利用效率,但各器官磷含量、磷积累量、磷利用效率均不随钾处理浓度的升高而呈现规律性的变化;橡胶树幼苗根、茎、叶各器官钾含量、钾积累量随钾处理浓度的升高而升高、钾利用效率则随钾处理浓度的提高而降低。差异显著性检验结果表明,除在根中0、1mg/LK2O处理钾利用效率差异不显著外,在根中其他处理间及在茎、叶中各处理间钾利用效率达差异极显著水平,钾利用效率更能体现不同钾浓度处理间的差异。 相似文献
2.
在营养液培养条件下研究了不同磷浓度对橡胶幼苗植株生长的影响。结果表明，不同磷浓度对橡胶苗主根长度、根冠比、根、茎叶中含磷量等都产生了显著的影响。随着磷浓度的增加，主根长度呈现先升高后下降的趋势。在不供磷和低磷水平下根冠比增加。橡胶树水培幼苗随着磷浓度的增加，根、茎、叶的含磷量呈增加的趋势。 相似文献
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磷素缺乏是我国及世界农业的普遍问题.本研究通过不同磷浓度胁迫处理茶树,发现根、新叶、老叶中磷含量都随着处理浓度的下降而降低,其中老叶中磷含量变化急剧,而新叶变化较缓慢.在缺磷条件下(100μmol·Lˉ1、10μmol·Lˉ1),老叶中的磷元素会重新转运到新生组织,实现磷元素的再次利用,而在过量磷浓度供应条件下(3000μmol·Lˉ1),磷元素则大量存储于老叶中,以维持体内磷平衡.茶树根部提取的总RNA量普遍比叶片低,但根部和叶片提取的RNA质量都符合反转录要求.试验通过荧光定量PCR方法,检测正常(1000μmol·Lˉ1)和低磷(10μmol·Lˉ1)胁迫下叶片和根中miR399a的表达量,发现在低磷胁迫下,miR399a在叶片和根中的表达量都显著提高,其中叶片提高约2.77倍,根提高约3.82倍,该结果与拟南芥、水稻等植物研究结果相一致. 相似文献
5.
以常规锰浓度为对照,设置锰缺乏和锰过量胁迫条件,研究游离态和络合态锰对不同基因型玉米早期氮代谢影响。结果表明,随着锰浓度的升高,根系硝态氮含量下降,品种东青1号下降幅度最小。品种垦粘1号和双玉201铵态氮含量随锰浓度增加呈先降低后升高趋势。吉农大516和东青1号随着锰胁迫增强,根部铵态氮含量下降。MnCl2·4H2O处理的玉米幼苗根系铵态氮积累程度大于EDTA-Mn处理,锰胁迫显著抑制根系可溶性蛋白合成。随着锰浓度增大,根系可溶性蛋白含量逐渐降低。MnCl2·4H2O处理根部可溶性蛋白下降程度大于EDTA-Mn处理。吉农大516根部可溶性蛋白含量最高。双玉201可溶性蛋白合成受抑制程度较大。锰胁迫影响根部氮素养分的有效分配,阻碍韧皮部运输而使得部分氮素于根部积累。锰胁迫条件下,东青1号为耐受品系,双玉201为敏感品系;游离态锰离子对玉米幼苗氮素转化抑制程度大于络合态锰离子。 相似文献
6.
采用砂培的方法研究不同营养液配比下尾巨桉幼苗生长及生理特性的变化.结果表明:不同营养液配比对尾巨桉幼苗生长及生理特性有显著影响,高氮处理下尾巨桉幼苗苗高、地径和总生物量显著高于中氮和低氮处理,低磷处理对苗高和地径生长促进作用明显;尾巨桉幼苗叶片净光合速率(Pn)随着氮水平的提高而升高,而随着磷、钾水平的提高呈现先升高后下降的趋势;随着时间的变化(4～6月),尾巨桉幼苗叶片中叶绿素及可溶性糖含量变化趋势相反,高氮磷钾能够显著提高叶绿素含量,中氨水平能够显著提高叶片中可溶性糖含量.不同营养液配比下尾巨桉幼苗生长及生理特性分析表明:高氮低磷中钾处理下尾巨桉幼苗在生长及生理特性方面均有较好表现. 相似文献
7.
NaCl处理对野大豆生理生化特性的影响 总被引：2，自引：1，他引：1
为明确NaCl处理条件下野大豆叶片抗氧化酶和有机渗透调节物质的变化,以不同浓度NaCl处理野大豆幼苗,对其抗氧化酶活性和渗透调节物质含量的变化进行分析.结果显示:随着NaCl浓度的升高,野大豆叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)活性先升高后降低,而过氧化氢酶(CAT)的活性呈持续下降趋势;丙二醛(MDA)含量在低盐度处理范围内变化不明显,高浓度NaCl处理时明显高于对照;随着NaCl浓度的升高,渗透调节物质脯氨酸含量增加,可溶性糖(SS)呈现先降低后升高的趋势.研究表明:在NaCl处理下野大豆主要通过SOD、POD清除活性氧,脯氨酸可能起到主要的渗透调节作用. 相似文献
8.
通过开顶式气室控制CO2浓度,对盆栽茶树进行试验测定,研究了大气CO2浓度升高对茶叶品质成分氨基酸、茶多酚、咖啡碱、可溶性糖和主要营养元素含量的影响。结果表明,在大气CO2浓度为550和750βμmol/mol时,与正常大气CO2水平相比,春茶氨基酸含量下降4.5%和12.2%,夏茶氨基酸含量降低1.7%和6.7%,秋茶降幅为2.9%和10.8%;茶叶咖啡碱含量降低3.1%~4.6%和5.1%~10.7%;但茶叶茶多酚和可溶性糖含量降CO2浓度升高而提高,茶多酚含量提高3.8%~6.0%和6.9%~11.3%,可溶性糖含量增加8.4%~14.4%和18.1%~28.2%。同时,大气CO2浓度的升高使茶叶营养元素氮、钾、钙、磷、钠含量有不同程度降低,而锌、镁、铁含量有所增加,其中,茶叶氮、钾元素含量降低6.1%~16.3%和12.9%~22.9%,锌、镁含量分别提高5.8%~17.8%和11.3%~16.0%。 相似文献
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《中国麻业》2017,(2)
通过种子萌发实验研究了不同浓度(0、1、2、10 mL/皿)不同苎麻品种根际土壤水浸液对模式植物拟南芥幼苗生长的化感效应,并运用相对实时定量PCR(QPCR)技术从基因水平探讨了不同浓度根际土壤水浸提液处理后与拟南芥生长素合成相关基因YUC1(AT4G32540)的表达。结果表明,随着苎麻根际土壤水浸液浓度的升高,拟南芥幼苗在中苎1号根际土壤处理下其根长与对照相比均呈现出抑制效应,在湘苎7号根际土壤处理下其根长与对照相比呈现出低促高抑现象。在中苎1号根际土壤处理下拟南芥幼苗丙二醛(MDA)含量随着苎麻根际土壤水浸提液浓度升高而上升,在湘苎7号根际土壤处理下拟南芥幼苗丙二醛(MDA)含量在低浓度时,与对照相比降低,当浓度升高,其含量呈现出升高趋势。在不同浓度根际土壤水浸提液处理下,拟南芥幼苗的过氧化物歧化酶(SOD)活性均表现为随处理浓度升高,SOD活性下降,且在中苎1号处理下,下降幅度较湘苎7号大。QPCR检测结果表明,2个苎麻品种处理下YUC1其基因的表达量随水浸提液浓度增加均降低,且中苎1号下降幅度较湘苎7号大。可见,随浸提液浓度升高,苎麻对拟南芥生长的化感胁迫性增强。 相似文献
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《Journal of Crop Improvement》2013,27(2):81-114
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.
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
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Whereas the concept that availability of resources drives seed production is sound in principle, it is incomplete as there are many solutions to the allocation of resources that derive from the trade-off between number and size. This paper examines evolutionary aspects of this trade-off in annual grain crops. The analysis is centred on the working hypotheses that, for a given species and environment, allocation of resources to reproduction involves (H1) high plasticity in seed number, which allows for variable resource availability, and (H2) a relatively narrow range of seed size that results from evolutionary and agronomic selection. Comparisons between crops and fish are used to highlight common evolutionary elements in taxa where parents provide little or no care to their offspring, with the consequence that both number and early survival of offspring, hence fitness of parents, are partially related to embryo size and reserves.
The plasticity of seed number in relation to availability of resources is analysed against the established relationship between offspring number and parent growth rate during critical stages. The notion that seed size is under stabilising selection is analysed against three conditions: (1) mean seed size is conservative for a given species and environment, (2) seed size affects fitness, and (3) seed size is heritable. Databases from published papers were compiled to analyse the relative variability of seed size and number, and the heritability of seed size. Evidence for and against the link between seed size and parental fitness is revised using the Smith–Fretwell model as framework (Am. Nat., 108, 499–506).
The proposal of high plasticity of seed number and narrow variability of seed size resulting from stabilising natural selection is generally consistent with evolutionary and genetic considerations. Agronomic selection may have reinforced natural selection leading to relatively narrow seed size in species such as wheat and soybean, where cultivated types retained high plasticity for seed number. In contrast, selection for one or few inflorescences in crops like sunflower and maize may have morphologically reduced seed number plasticity and increased variability of seed size and its responsiveness to resource availability in relation to their wild ancestors. 相似文献
15.
Yanhua Lu Chongwei Zhang Peter Bucheli Dongzhi Wei 《Plant foods for human nutrition (Dordrecht, Netherlands)》2006,61(2):55-63
Flavonoids-enriched tissues of citrus such as peel, immature fruit and flower are consumed as culinary seasonings, tea ingredients in China for centuries. This HPLC quantitative study on the five citrus flavonoids, naringin, hesperidin, neohesperidin, sinensetin and nobiletin on a wide range of Chinese citrus fruits and several Traditional Chinese Medicinal food ingredients in East China, revealed a great diversity in flavonoid composition. Huyou peel (C. paradisi cv. Changshanhuyou) was found to be the best naringin (3.25%) and neohesperidin (2.76%) source; C. aurantium, a major ingredient of several citrus-related TCM, is also a suitable source of naringin and neohesperidin, and a good juice source for flavanone glycosides; the peel of Wenzhoumiju (C. unshiu) is one of the richest local species in hesperidin (up to 6.25%); Zaoju (C. subcompressa) has the highest content of nobiletin (0.59%), a polymethoxylated flavone. LC-ES-MS analysis of Zanthoxylum genus for flavonoids revealed for the first time the presence of significant amounts (0.74%) of hesperidin in the root of Liangmianzhen (Z. nitidum (Roxb.) DC), a relative of Sichuan pepper, which is a spice widely used in China. 相似文献
16.
Summary The viability of five pathogens was decreased by treatment with hot water when tested in vitro.Polyscytalum pustulans was most sensitive andRhizoctonia solani least sensitive.
Potato tubers were exposed to 55°C for 5 min in a commercial continuous hot water treatment plant using naturally contaminated
seed tubers and tubers which had been inoculated by dipping in comminuted cultures. The frequency of eyes colonised byP. pustulans, Helminthosporium solani, andR. solani was reduced to virtually zero and the effect persisted on tubers subsequently stored at 4°C and at 15°C for up to 16 wk.
Results withColletotrichum coccodes were inconclusive. Treatment suppressedPenicillium spp. which, however, rapidly recolonised the eyes during storage, leading to higher contamination levels in the treated than
in the untreated tubers. With tubers inoculated withPhoma foveata, good control was achieved when the incubation period before treatment was 10 d but not when the period was 42 d. 相似文献
17.
《Journal of Crop Improvement》2013,27(2):379-400
Summary Heterocyclic 1,4-benzoxazin-3-ones and related benzox-azolinones are important natural products of the cereal crops maize, wheat and rye. Much research has focused on the role of these compounds as defensive agents against plant diseases and pests. Studies of a wide variety of biological effects on herbivores and nematodes, plant pathogenic fungi and bacteria are reviewed in this article. Phytotoxic activity of the compounds is also considered with respect to allelopathic interaction with higher plants. Recent investigations of molecular aspects of interactions of cyclic hydroxamic acids and related benzoxazo-linones with acceptor organisms have demonstrated different effective detoxification strategies and tolerance mechanisms. This research has greatly advanced our knowledge about the multiple roles that these allelochemicals play in ecological systems. 相似文献
18.
Potential of dry fractionation of wheat bran for the development of food ingredients,part I: Influence of ultra-fine grinding 总被引：1，自引：0，他引：1
Youna Hemery Marc Chaurand Ulla Holopainen Anna-Maija Lampi Pekka Lehtinen Vieno Piironen Abdelkrim Sadoudi Xavier Rouau 《Journal of Cereal Science》2011
Wheat bran is an undervalued by-product of white flour and has great nutritional potential due to its high content in fibres and bioactive compounds. Micronized bran could be used as a food ingredient to improve the nutritional potential of cereal products, or be used as a starting material for other processes (bioactive compound extraction or bran fractionation). The aim of this work was to find a way to efficiently decrease the particle size of bran. The influence of the grinding temperature (ambient or cryogenic grinding) on the granulometric distribution of particles, their composition, and their microstructure was studied, at lab-scale and pilot-scale. It showed that the intrinsic characteristics of bran (glass transition within intermediate layers at −46 °C) had more influence on its grinding behaviour than the type of grinding device used: the particles size distributions obtained after grinding at lab-scale and pilot-scale were very similar. At both scales, the granulometric curves were narrow for cryogenic grinding, while for ambient grinding they were spread over the whole particle size range. Ultrafine particles were obtained in both ambient and cryogenic conditions. Negative temperatures, by increasing the material’s brittleness, favoured a fast fragmentation of bran: one step of cryogenic grinding allowed a median particle size of nearly 50 μm to be reached, whereas three successive steps of ambient grinding were needed for the same result. On the other hand, ambient temperature favoured the dissociation of the different constituent layers of wheat bran, and produced less composite particles than cryogenic grinding. 相似文献
19.
Multiple use of plants: Studies on selenium incorporation in some agricultural species for the production of organic selenium compounds 总被引：3，自引：0，他引：3
The technique of spraying plants with inorganic forms of selenium can be employed for phytochemical production of organic selenium compounds. Fractionation of the plant material makes it possible to produce a highly concentrated and well defined selenium supplement with potential use in animal and human nutrition. The fractionation also gives opportunities to combine production of organic selenium compounds with other products, for example plant fibres. Multiple use of plants can contribute to a more efficient utilization of land area (in comparison to monocultures solely adapted to food production). It also gives the opportunity to develop systems suitable for long term fixation of carbon, as long as the plant material is not reoxidised to carbon dioxide. Plant fibres could provide raw material for the production of paper or building materials in combination with the production of organic selenium compounds preferentially accumulated in another fraction of the processed plant. 相似文献
20.
Summary
Macrosiphum euphorbiae, collected in the field from potato plants infected with potato leafroll virus (PLRV), transmitted the virus to fewer potato
plants in a field trial than did laboratory-rearedMyzus persicae. In the laboratory,M. persicae was the only efficient vector of PLRV fromPhysalis floridana seedlings, potato sprouts or excised leaves toP. floridana. Two clones ofM. euphorbiae and one clone ofAulacorthum solani transmitted PLRV from infected potato plants toNicotiana clevelandii as effeciently asM. persicae but a clone ofAphis gossypii was an inefficient PLRV vector. An isolate of PLRV, whichM. persicae transmitted inefficiently from potato toN. clevelandii, was also transmitted inefficiently byM. euphorbiae andA. solani. 相似文献