句句深入人心

<正>1.莎士比亚说:再好的东西都有失去的一天。再深的记忆也有淡忘的一天。再爱的人,也有远走的一天。再美的梦也有苏醒的一天。该放弃的决不挽留。该珍惜的决不放手,分手后不可以做朋友,因为彼此伤害过!也不可以做敌人,因为彼此深爱过     

植物抗坏血酸氧化酶的研究进展

抗坏血酸氧化酶在植物生理中具有重要的意义,不但与植物的生长发育和抗衰老有关,而且和果实的储藏有关。介绍了抗坏血酸氧化酶活性的测定方法;分析了影响抗坏血酸氧化酶活性变化的主要因素,认为抗坏血酸氧化酶的活性受到金属离子、有机无机小分子和外界环境条件等因素的影响;概述了农作物、果树和蔬菜关于抗坏血酸氧化酶活性的研究状况。采用不同的处理可以提高一些农作物的抗病性,延长果实的储藏期限,提高蔬菜种子的发芽率和一些子实体的使用价值。     

肉类冷加工的基本原理

1.肉类冷加工的温度范围 　　肉类及其制品的保藏方法很多,如腌制、防腐剂、抗菌素、一定剂量的放射、脱水干制、低温冷藏等不同方法.其中应用最广泛、最经济的是采用人工制冷的低温保藏,它不仅保藏时间长,而且在冷加工中不会引起肉的组织结构和性质发生根本的变化,所以采用低温保藏肉类是现代的最完善的方法之一.……     

肉品的保鲜与包装

影响鲜肉质量的主要因素有内因性的酶解作用造成的蛋白质分解及色泽的变化、外因性的微生物繁殖造成的腐败和氧的存在造成的脂肪氧化等.畜肉和禽肉一般都是在宰杀后进入流通领域.畜禽宰杀后,肌肉要经过死后僵直阶段,即肌肉中的高能物质ATP水平下降,肌动蛋白和肌球蛋白结合为肌动球蛋白.     

再制奶酪在中国的发展前景

随着中国居民生活水平的提高,营养意识的增强,在不久的将来,奶酪必将会成为我们日常饮食的一部分.再制奶酪作为传统奶酪的延伸,已经有了近100年的发展历史.它特有的原料选用和生产工艺使我们能够在保留并提高传统奶酪的营养价值的前提下,开发和生产出适合中国人口味的奶酪美食,因此在中国乳制品市场上有着很广阔的发展前景.     

兰花在全球花卉贸易中的地位及发展动态

近年来飞速发展的兰花产业,成为中国花卉业的重要组分,但发展中存在着一定的盲目性。基于此,有必要借鉴已趋成熟的国际兰花产业的发展经验和思路,以获悉不同种类兰花的适宜发展份额,剖析中国兰产业发展思路和国际发展空间,有助于指导兰花产业的发展。该文研究了近年全球兰花切花、盆花的进、出口贸易及主要进、出口国家的兰生产、消费情况,对其产量、面积、贸易额等进行了分析。结果表明蝴蝶兰、大花蕙兰、石斛兰等兰花为主要的贸易种类,其中,仅蝴蝶兰2005年全球消费量已达1.5亿株。主要的生产和出口国（地区）,石斛兰和万代兰是泰国,蝴蝶兰是中国台湾;世界兰花切花、盆花的最大出口国和地区分别是泰国、台湾;兰花切花的最大进口和消费国是日本;兰花盆花的最大进口国是美国;马来西亚、新加坡、新西兰等国家主要发展兰花切花。通过回顾兰花进出口大国的生产、贸易、销售状况,理清了国际兰花的发展和趋势,同时对中国兰产业的发展有借鉴和启迪作用。     

怎样控制动物产品兽药残留

兽药残留是指动物产品的任何可食部分所含兽药的母体、代谢产物以及与兽药有关的杂质残留,简称药残.由于养殖业的迅速发展,兽药的使用范围及用量也在不断增加,药物的应用在提高动物产品产量的同时,引起了极为严重的食品中兽药残留,主要表现为变态反应、细菌耐药性、三致作用(致癌、致畸、致突变)以及激素(样)作用等.     

猪的宰后检验

猪的宰后检验是宰前检验的继续,是将宰前无法检出的某些传染病和寄生虫病以及临时发现的某种临床症状不明显的疾病,通过宰后剖检与实验室检验将其检出,并进行无害化处理,从而消除传染源,有效地控制疫病的传播、扩散和蔓延,保护养殖业健康发展,保障人们的食肉安全.……     

合理调整结构拓宽农产品市场销售渠道

农村是市场经济的载体,是工农业产品的集散地.农业又是国民经济的基础.几十年来,农业经济在国民经济中一直占有十分重要的地位.随着经济的不断增长,“三农“ 问题已成了全社会关注的焦点.……     

仙肉植物“花园风”

赏玩仙肉植物,不一定非要成为火眼金睛的"品种控"。选一些平凡的种类,淘几个别致的花盆,经过巧妙的设计组合,便有了不一样的景致,不一样的意境。浪漫感性的花支,一定不想忽略这种美妙的体验吧。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.