甘蓝型油菜自交不亲和系杂种纯度鉴定

利用共显性分子标记技术SSR、显性形态标记性状花叶及显性生化标记种子芥酸含量鉴定甘蓝型油菜自交不亲和系SI-1300与恢复系花叶恢杂种F1种子纯度.结果表明,3种方法鉴定结果基本一致,F1杂种种子纯度达到91%以上;不同SSR引物鉴定结果完全相同,一对SSR引物即可用于鉴定F1杂种纯度.SSR扩增产物具有很高的多态性和严格的保守性,不仅可以用于油菜杂种纯度鉴定,亦可以用于不同品种(组合)真实性鉴别.研究结果还表明,自然条件下放养蜜蜂用于自交不亲和系杂种制种是一种稳妥、切实可行的方法.     

基于NY/T 1433—2014推荐SSR标记检测不同世代恢复系配制杂交种的纯度研究

采用田间性状稳定的不同世代恢复系YR179(F8、F9和F10代)、YR092(F8和F9代)和YR018(F8和F9代)及其与稳定不育系03S配制的杂交种为材料,利用《水稻品种鉴定技术规程SSR标记法》(NY/T 1433—2014)中推荐的48对SSR引物检测各世代恢复系的纯合位点数,通过室内分子鉴定与田间植株性状鉴定的一一对应检测,研究不同世代恢复系所配杂交种种子室内分子鉴定纯度结果与田间种植鉴定纯度结果的吻合度,并对各杂株类型进行一一对应分析。结果表明,当YR179、YR092和YR018分别选育至F10、F9和F9代时,全部48个位点均已完全纯合,此时,其对应杂交种室内分子鉴定纯度与田间种植鉴定纯度吻合率分别为99.4%、99.4%和100%,且各杂株类型的室内与田间鉴定结果也基本一致。说明当恢复系完全纯合时,可用室内SSR分子标记鉴定替代田间种植鉴定来鉴定其杂交种的纯度。     

龙眼品种SRAP指纹检索系统的开发及遗传多样性研究

应用SRAP技术开发了龙眼指纹检索系统并进行了遗传多样性分析。12对引物组合在16份龙眼及龙荔种质中共扩增出257条DNA带,其中248条为多态带(占96.5%),平均每个引物扩增多态性带20.7条。17份材料间的遗传相似系数范围为0.399~0.871。利用Me6Em7、Me5Em4、Me2Em8等3对引物开发的指纹检索系统,可以区分全部17份种质。根据相似系数进行聚类分析,16个龙眼品种和龙荔分成2大组,龙眼品种间的聚类结果基本反映了供试材料之间的亲缘关系。     

热研一号油绿苦瓜种子纯度的SSR鉴定

利用SSR分子标记技术对‘热研一号’油绿苦瓜杂交种纯度进行鉴定。从26对SSR引物中筛选出在亲本间表现明显多态性的8对引物，其中5对为共显性标记，3对为显性标记，利用3对共显性标记对其进行纯度检测。结果表明，‘热研一号’油绿苦瓜种子纯度为99.38％，与田间形态学鉴定结果高度一致。说明SSR分子标记可以快速、准确地鉴定‘热研一号’油绿苦瓜杂交种纯度。     

我国江淮产区主要芝麻品种的SRAP指纹图谱分析

利用SRAP分子标记对江淮主产区8个芝麻品种进行指纹图谱分析。32对有效扩增的引物中有27对扩增出多态性,占84.37％;27对多态性引物共扩增465个位点,多态性位点158个,占33.98％;平均每对引物可检测位点17.22个,其中多态性位点平均5.85个;8个品种相互间的相似系数在0.7861～0.9711之间,平均为0.9079;用一对引物Em07/Me09便可将8份芝麻品种区分开来,用其构建的指纹图谱的置信概率达到99.6948％。     

基于SRAP标记的国兰种质资源遗传多样性分析

采用SRAP（sequence related amplified polymorphism）技术对154份国兰（杂交兰）种质资源的亲缘关系进行分析。从168对SRAP引物中筛选出16对条带多、带型清晰、多态性强的引物组合对所有样品进行扩增,共获得874条带,其中多态性条带857条,多态性比率为98.1%,平均每对引物每个样品产生5.74条带。UPGMA聚类分析表明:Me6-Em3引物能较好地揭示154份国兰种质间的遗传多样性与亲缘关系,在遗传相似系数0.818处将它们分为8个类群,遗传相似系数变化范围为0.772~1.000。此外,发现引物Me8-Em4、Me11-Em2和Me12-Em11可以较可靠地联合鉴定建兰。该研究结果可为国兰种质资源利用及杂种后代鉴定提供参考。     

瓜类砧用南瓜种子纯度鉴定技术研究进展

通过对瓜类砧用白子南瓜种子的常规鉴定、电泳鉴定、分子标记鉴定等多种方法进行分类研究,并对各种鉴定方法的优缺点及适用性进行分析评述,指出SRAP／RSAP标记是未来瓜类砧木南瓜种子纯度鉴定的主导方向。     

SSR、SRAP、ISSR分子标记在茶树品种亲本鉴定上的比较分析

为鉴定湘波绿2号的父本,同时为茶树亲本鉴定和亲缘关系分析等研究提供分子标记参考,本研究采用SSR、SRAP、ISSR 3种分子标记体系,在对湘波绿2号与其母本和5个可能父本进行亲缘关系分析基础上,比较了这3种分子标记体系的多态性条带比率（PPB）、多态性信息含量（PIC）、多样性指数（DI）、引物解析强度（Rp）、分子标记指数（MI）等指标。29对SSR引物共检测到等位位点83个,平均每对引物2.86个,引物PPB、PIC、DI、Rp、MI平均值分别为77.01%、0.55、0.29、1.31、0.95。17对SRAP引物共检测到等位位点139个,平均每对引物8.18个,引物PPB、PIC、DI、Rp、MI平均值分别为71.70%、0.84、0.15、3.65、3.59。10个ISSR引物共检测到等位位点90个,平均每个引物9.00个,引物PPB、PIC、DI、Rp、MI平均值分别为69.76%、0.85、0.15、4.21、4.71。3种标记体系的MI、Rp、PIC趋势一致,ISSR最高,依次为SRAP和SSR,而PPB和DI正好相反。以上结果表明,ISSR和SRAP标记具有较高的标记效率,而SSR标记具有丰富的多态性。不同分子标记体系获得的品种间相似系数有所不同,但湘波绿2号与湘波绿和福鼎大白茶聚为一类,说明湘波绿2号与其关系较近,湘波绿可能为湘波绿2号的父本。     

利用ISSR标记鉴定杂交水稻种子纯度初步研究

以华南地区生产上大面积应用的7个杂交水稻组合及其父母本为材料,研究了利用ISSR标记鉴定杂交稻种子纯度的可行性。结果从60条ISSR引物中筛选出4条引物,能分别在特定杂交稻组合的父母本间扩增出多态性条带,杂种F1代的带型除特优048、湛优226为偏父型外,其余供试杂交稻组合均为互补型,能有效将杂交稻组合与其亲本区分开,说明ISSR标记可用于杂交稻种子的纯度鉴定。     

热辣2号辣椒纯度鉴定及优良自交系遗传多样性分析

为了提高种子质量和充分利用辣椒种质资源,应用SSR分子标记对热辣2号杂交种纯度进行鉴定并对部分辣椒优良自交系进行遗传多样性分析。以热辣2号母本材料CAYB02和父本材料CAYB01为模板筛选85对辣椒SSR引物,其中12对引物在亲本间能扩增出明显的多态性,多态性比率为14.12%,多态性标记分别位于辣椒1、3、4、6、7、9、11、12号染色体,利用3对位于不同染色体上的SSR标记对热辣2号黄灯笼椒杂交种的纯度进行鉴定,热辣2号种子纯度为98.79%,标记鉴定结果与田间鉴定结果一致。研究结果表明,利用SSR标记鉴定辣椒杂交种纯度是切实可行的。利用12对多态性明显、稳定可靠的SSR引物对部分辣椒自交系进行遗传多样性分析,共扩增出60条条带,多态性位点比率为100%,平均每对引物检测出5个等位基因。30份辣椒自交系间遗传相似系数变幅为0.33~1.00,平均为0.65,表明供试材料间具有丰富的遗传多样性。聚类分析结果表明,在遗传相似系数为0.47时,可以将中国辣椒和一年生辣椒区分开来。在遗传相似系数为0.85时,30份辣椒优良自交系分为11个类群,辣椒种质遗传关系与地理来源和农艺性状具有一定的相关性。     

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.