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1.
为了探索小麦成熟胚基因枪转化的影响因素,对Z50、郑麦366、Bobwhite和西农529四个小麦基因型的成熟胚进行了愈伤组织的诱导及植株分化再生研究,同时以郑麦366的成熟胚为外植体分析了不同渗透处理剂、每枪金粉用量和轰击距离对基因枪转化过程的影响。结果表明,Z50、郑麦366、Bobwhite三个基因型的出愈率及胚性愈伤率差异不大,均在85%以上,西农529的出愈率较低,胚性愈伤率与Z50、郑麦366和Bobwhite差异显著。不同小麦基因型分化率差异显著,其中郑麦366分化率最高(39.26%)。基因枪转化结果显示,渗透剂对小麦愈伤组织生长均有一定的抑制作用,蔗糖的抑制作用比甘露醇弱;每枪金粉用量100μg的分化率较高(45.57%),但金粉用量100μg时的GUS瞬时表达量与金粉用量60μg时差异不显著,轰击距离为9cm时的分化率和GUS瞬时表达量均比6cm和12cm时高;蔗糖用量0.4mol、金粉用量60μg、轰击距离9cm时GUS瞬时表达量最高,该条件下小麦成熟胚转化频率达0.67%,已初步优化了基因枪介导的小麦成熟胚遗传转化体系。 相似文献
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为了明确不同因素对小麦基因枪法转化效率的影响。用PDS-1000／He型基因棺将抑制叶片衰老基因Psag12-ipt转入小麦幼胚细胞，通过对报告基因GUS瞬时表达的检测，研究了金粉用量、质粒DNA用量及轰击次数对转化率的影响。结果表明，金粉用量在100-400μg范围内，时幼胚瞬时表达率影响不大，幼胚瞬时表达率在73．7%～85．0％之间，但随金粉用量的增加，细胞瞬时表迭率明显提高；质粒DNA用量以每枪2．0μg为最佳；轰击2枪幼胚和细胞瞬时表达率明显高于轰击1枪。 相似文献
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以玉米自交系E28的胚性愈伤组织为受体,分别利用农杆菌介导法和基因枪轰击法对携带有GUS基因和Bar基因的质粒进行转化,借助GUS基因的瞬时表达率和抗性愈伤组织比例建立体系,并对两种方法进行比较。农杆菌介导法以OD6000.6、浸染30 min、25℃共培养3 d、加入0.01%的silwet L-77为最佳参数;基因枪轰击法为4.5 MPa、11 cm轰击距离最佳参数。农杆菌介导法与基因枪轰击法的GUS瞬时表达率没有显著差异,基因枪法的抗性愈伤组织比例显著高于农杆菌介导法,基因枪轰击法较农杆菌介导法更有利于获得转基因后代。 相似文献
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以萌动1d的半片种子为靶组织,植物表达载体质粒pCAMBIA1301为外源DNA,通过GUS瞬时表达检测,研究了轰击次数、轰击距离、培养时间及靶组织放置方式对基因枪转化效率的影响。结果表明：轰击次数对转化效率有很大影响,轰击2或3次时GUS瞬时表达效率显著高于1次;在所试的3、6、9、12cm4个轰击距离中,9cm轰击距离对GUS瞬时表达效率最高;靶组织培养时间长短对转化效率也有很大影响,培养2d时,转化效率最高,平均每个半片种子达到217．5个蓝色斑点,随着培养时间的延长,GUS基因瞬时表达呈下降趋势,至第28天以后趋于稳定;靶组织不同放置方式对转化效率无明显的差异。本研究优化了影响基因枪法转化大豆萌动种子的主要因素,从而为基因枪介导大豆遗传转化技术体系的建立提供了参数。 相似文献
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基因枪及其与农杆菌相结合的茶树外源基因转化条件优化 总被引：7，自引：0，他引：7
以GUS为报告基因,对基因枪介导的转化茶树愈伤的有关参数进行优化。比较了不同的预培养条件,含有PVP的培养基可提高转化频率。渗透处理不仅不能提高GUS的表达率,反而使愈伤再生困难。每枪DNA和钨粉的用量分别为0.25μg,125μg时,可得到较高的转化率。在轰击压力7MPa,射程5cm的条件下轰击一次,不论对GUS表达还是愈伤的再生都是较为适合的轰击条件。比较了农杆菌法(AGR),基因枪法(BOM)及农杆菌与基因枪结合(BTA,BPA和BOA)等方法对茶树遗传转化效率的影响。瞬间表达的结果及抗性愈伤筛选的结果都显示,农杆菌与基因枪结合使用比两种方法单独使用更有助于提高茶树转化的效率。 相似文献
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为验证小麦病程相关蛋白基因TαPR-1的功能，利用gus基因瞬间表达技术对基因枪法转化小麦幼胚的两个重要参数金粉用量和轰击距离进行了优化。研究结果表明,金粉用量为250．0μg．轰击距离9cm的轰击参数最为理想，GUS瞬间表达率和平均蓝点数分别可达89．8％和33．7个。采用此轰击参数．将TαPR-1基因导入扬麦158幼胚．经3～5mg／L Bialaphos筛选获得49株抗性再生植株．经PCR、Southern杂交分析．其中2株为阳性植株．转化率为0．11％。对转基因小麦植株进行苗期离体叶段和田间成株白粉病接种鉴定．初步结果表明，转基因植株对白粉病抗性与对照相比无明显差别。 相似文献
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基因枪法获得玉米转基因植株的研究 总被引：2，自引：0，他引：2
采用基因枪轰击转化技术将含有抗除草剂chlorsulfuron基因AHAS的PCD220质粒导入玉米愈伤组织,并再生出具有抗该除草剂的转基因植株,同时研究了影响玉米基因枪转化效率的因素。基因枪轰击时,金粉用量、轰击次数及轰击距离对愈伤组织的转化率有较大影响。转化时,以金粉用量100 μg/枪、轰击2次、发射点与靶细胞的距离9 cm最合适。对所获得的转化植株进行PCR分析及Southern杂交鉴定,部分转化植株呈PCR阳性和明显的杂交信号,说明抗除草剂绿黄隆的基因AHAS已整合到玉米基因组当中,将转基因植株进行自交,获得了T0代的种子。 相似文献
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为验证小麦病程相关蛋白基因TaPR-1的功能,利用gus基因瞬间表达技术对基因枪法转化小麦幼胚的两个重要参数金粉用量和轰击距离进行了优化.研究结果表明,金粉用量为250.0 μg,轰击距离9cm的轰击参数最为理想,GUS瞬间表达率和平均蓝点数分别可达89.8%和33.7个.采用此轰击参数,将TaPR-1基因导入扬麦158幼胚,经3～5 mg/L Bialaphos筛选获得49株抗性再生植株,经PCR、Southern杂交分析,其中2株为阳性植株,转化率为0.11%.对转基因小麦植株进行苗期离体叶段和田间成株白粉病接种鉴定,初步结果表明,转基因植株对白粉病抗性与对照相比无明显差别. 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
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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
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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
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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
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《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
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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
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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
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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