花生体胚诱导和植株再生研究

在含２０ｍ ｇ／Ｌ２，４－ Ｄ ＭＳ诱导培养基上，未成熟种胚和成熟种子种胚为外植体，光照培养下体胚诱导率分别为９２％ 和７８％ ，单个外植体平均产胚４８ 和４１ 个；而成熟种子胚小叶和未成熟种子子叶体胚诱导率均较低。以成熟种子种胚为外植体，２０ｍ ｇ／Ｌ２，４－ Ｄ和５ｍ ｇ／ＬＰｉｃｌｏｒａｍ 暗培养体胚诱导率分别为５５％ 和５８％ ，单个外植体平均产胚分别为４４和４２ 个。在含５ｍ ｇ／ＬＰｉｃｌｏｒａｍ 培养基上，１３个花生品种（系）体胚诱导率６％ ～８３３％ ，产胚量１２～４５个，差异显著，珍珠豆型花生品种体胚诱导率、产胚量普遍高于普通型花生品种。８ 个品种（系）体胚在含１０ｍ ｇ／ＬＢＡ 的ＭＳ培养基上枝条再生率３６３％ ～７７８％ 。再生枝条在含０３ｍ ｇ／ＬＮＡＡ ＭＳ培养基上生根后，植株移到温室已正常开花、结荚。     

绿宝石喜林芋叶片培养及植株再生

结果表明：诱导绿宝石喜林芋叶片产生愈伤组织频率最高的培养基是ＭＳ＋ＢＡ０．０５ｍｇ／Ｌ＋２．４－Ｄ１．０ｍｇｇ／Ｌ。最适于愈伤组织分化的基本培养基是Ｎ６；３ｍｇ／Ｌ的ＢＡ、ＺＴ和ＫＪ均能诱导愈伤组织产生不定芽，其中以ＢＡ为好；ＣＨ对愈伤组织的分化有促进作用。Ｎ６＋ＢＡ７ｍｇ／Ｌ＋ＩＢＡ１．０ｍｇ／Ｌ对不定芽的增殖效果较好，３０ｄ可增殖９．４倍。１／２ＭＳ＋ＩＢＡ０．５ｍｇ／Ｌ诱导生根效果好。试管苗     

魔芋高效再生体系的建立与优化

研究不同激素及浓度配比对魔芋愈伤组织、不定芽和根诱导的影响。结果表明,诱导愈伤组织的最佳激素组合为ＭＳ＋６－ＢＡ０.5 ｍｇ／Ｌ＋ＮＡＡ ０．５ ｍｇ／Ｌ,其诱导率为８２％;诱导不定芽分化的最佳配方为ＭＳ＋６－ＢＡ １．５ ｍｇ／Ｌ＋ＮＡＡ ０．５ ｍｇ／Ｌ,其分化率为４９０％;诱导生根的最佳激素组合配方为ＭＳ＋ＮＡＡ ０．５ ｍｇ／Ｌ＋６－ＢＡ １．０ ｍｇ／Ｌ,其生根率为９０％。     

花生去子叶幼胚的丛生芽诱导和植株再生

授粉后２５－３０天的花生幼胚，去子叶后，在ＭＳ２（ＭＳ＋ＢＡ１．０ｍｇ／Ｌ＋ＣＨ３００ｍｇ／Ｌ＋ＰＶＰＰ０．３％＋椰计５０ｍｌ／Ｌ＋蔗糖４％＋琼脂０．８％）培养基中，置３００ｌｕｘ弱光和２０℃±１℃条件下，培养２１－２８天，能有效地产生丛生芽；在ＭＳ２中诱导培养后的去子叶幼胚的生长点切去，在改良无激素培养基（ＭＳ１）中培养１４天，转入ＭＳ３（ＭＳ＋ＢＡ６．０ｍｇ／Ｌ＋ＮＡＡ０．４ｍｌ／Ｌ＋Ｄ－生物素０．１ｍｇ／Ｌ＋ＣＨ３００ｍｇ／Ｌ＋酵母浸出物２００ｍｇ／Ｌ＋椰计５０ｍ／Ｌ＋ＰＶＰＰ０．３％＋蔗糖２．５％＋琼脂０．８％）培养基，置２５℃±１℃，３５００ｌｕｘ光照条件下培养２１－２８天，８０％的外植体分化出丛生芽，继而长成无根带叶小苗．．平均每外植体产生８．１个丛生芽，最多可达４０个．诱根后小苗移植田间８０％植株成活并开花结实。品种（系）间差异不显著。     

诸葛菜花器组织培养及其植株再生

诸葛菜的花瓣、萼片、花丝在ＭＳ附加６—ＢＡ与２，４—Ｄ的培养基上培养７～１０ｄ，诱导形成愈伤组织。愈伤组织在ＭＳ＋ＮＡＡ１ｍｇ／Ｌ＋６－ＢＡ３ｍｇ／Ｌ的分化培养基上培养７ｄ左右分化出芽，每块愈伤组织形成３～４个芽。花托、花序轴切段在分化培养基上可直接出芽形成植株。     

大豆花药培养几个问题的研究

本文研究了大豆花药培养中的培养基、基因型、激素配比、糖分种类及浓度、取材时期、预处理温度、接种方式、有机添加物等因素对愈伤组织诱导频率的影响。认为大豆花药在培养基上的脱分化启动具有群体效应，合适的取材时期是单核中晚期。高浓度蔗糖能抑制体细胞愈伤组织的产生，而愈伤组织的分化则需要较低的蔗糖浓度。愈伤组织在Ｂ＿５＋０．５ｍｇ／１ＮＡＡ＋１．０ｍｇ／１ＫＴ＋１％蔗糖和改良ＭＳ＋０．１ｍｇ／１ＩＢＡ＋０．１ｍｇ／１ＧＡ＿３＋０．４ｍｇ／１ＮＡＡ＋０．５ｍｇ／１ＢＡ＋０．５ｍｇ／１ＫＴ＋０．５ｍｇ／１ＺＴ＋０．５ｍｇ／ｌ生物素＋２％蔗糖等培养基上分化出了芽，在改良ＭＳ＋０．５ｍｐ／１ＩＢＡ＋０．５ｍｇ／１ＢＡ＋０．５ｍｇ／１ＫＴ＋０．５ｍｇ／１ＺＴ＋５％蔗糖＋１％麦芽糖等培养基上产生了胚状体。     

马铃薯优化再生系统的建立

本试验研究了六种培养基系统对马铃薯东农３０３，Ｆａｖｏｒｉｔａ和极早三个品种来源的不同外植体的愈伤组织诱导和植株再生的影响，筛选出了适合植株再生的最佳外植体、最佳外植体大小及最佳培养基系统。适合植株再生的最佳外植体为叶片；最佳外植体大小为叶片０．５ｃｍ２、茎０．５ｃｍ、块茎０．２５ｃｍ２×０．３ｃｍ，适合于茎、块茎及叶的有效培养基系统分别为：①ＭＳ＋３ｍｇ·Ｌ-１ＢＡ＋０．０１ｍｇ·Ｌ-１ＮＡＡ（ｐｈ５．６）４周ＭＳ＋０．３ｍｇ·Ｌ-１ＧＡ３（ｏＨ５．６）；②ＭＳ＋１．７５ｍｇ·Ｌ-１ＺＴ＋０．８７ｍｇ·Ｌ-１ＩＡＡ（ｐＨ５．８）；③ＭＳ＋２．２５ｍｇ·Ｌ-１ＢＡ＋０．１８６ｍｇ·Ｌ-１ＮＡＡ（ｐＨ５．８）２周ＭＳ＋５ｍｇ·Ｌ-１ＧＡ３＋２．２５ｍｇ·Ｌ-１ＢＡ（ｐｈ５．８）。     

甜菜基因型的筛选及胚性细胞系建立的研究

通过以甜菜未成熟胚为外植体诱导愈伤组织，再将产生的愈伤组织转移至分化培养基（ＭＳＢ培养基附加１．０ｍｇ／Ｌ６－ＢＡ、３％蔗糖、８％琼脂）进行分化力测试实脸，筛选出两个再生能力强的基因型─８９３０、ＧＤ＿２．通过挑选淡黄色或灰白色、呈颗粒状的愈伤组织继代培养，经调节培养基的ＩＡＡ和ＮＡＡ的浓度，得到再生能力强的胚性愈伤组织，建立了胚性细胞无性系。     

甘蔗人工种子的最佳制作流程及其提高萌发率的研究初报

以闽选７０３为材料，在Ｎ６（或ＭＳ）＋２，２－４Ｄ２．２ｍｇ／Ｌ＋ＣＨ（水解酷蛋白）１．５ｇ／Ｌ培养基上诱导产生胚状体。利用１／２ＭＳＯ的５．５％海藻酸钠包裹体细胞胚，播种在４种不同的固体培养基上，其中播种在培养基１／２ＭＳ＋ＢＡ２ｍｇ／Ｌ＋ＮＡＡｌｍｇ／Ｌ＋ＡＣ（活性炭）０．５％的人工种子萌发率为３１．７％，比前人报道的２７．６％（２）提高４．１％。本文最后还探讨了活性碳对生根的作用。     

香荚兰细细胞培养及产香兰素研究初报

香荚兰的幼茎在ＭＳ＋ＢＡ１μｇ＋ｍＬ＋ＮＡＡ５μｇ／ｍＬ培养基上培养４０ｄ,其表面形成白色,块状的愈伤组织。愈伤组织在ＭＳ＋２,４－Ｄ１μｇ／ｍＬ＋ＢＡ１μｇ／ｍＬ＋ＮＡＡ４μｇ／ｍＬ＋２．５％ｓｕｃｒｏｓｅ的半固体培养基上快速增殖培养。     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

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.     

Novel food and non-food uses for sorghum and millets

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.     

Evolutionary aspects of the trade-off between seed size and number in crops

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.     

Citrus Flavonoids in Fruit and Traditional Chinese Medicinal Food Ingredients in China

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.     

Effect of a continuous hot water treatment of potato tubers on seed-borne fungal pathogens

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.     

Role of Benzoxazinones in Cereals

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.     

Potential of dry fractionation of wheat bran for the development of food ingredients,part I: Influence of ultra-fine grinding

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.     

Multiple use of plants: Studies on selenium incorporation in some agricultural species for the production of organic selenium compounds

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.     

Biological factors influencing the transmission of potato leafroll virus by different aphid species

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.