高粱抗病虫优异种质资源鉴定与筛选研究

1996～2000年,在田间采用人工接菌法进行高粱抗病性鉴定和利用田间自然发生的害虫种群与人工辅助接虫相结合的方法进行高粱抗虫性鉴定,对l282份高粱种质资源进行了高粱丝黑穗病、高粱靶斑病、高粱蚜虫和玉米螟等4种病虫害的抗性同步鉴定。划清了被鉴定资源对不同病虫害的抗性等级,筛选出兼抗2种病虫害的双抗性资源93份,兼抗3种病虫害的多抗性资源9份。这些抗病虫特性优异高粱资源,对于我国高粱抗病虫育种和选育多抗性品种具有重要的利用价值。     

高粱种质资源抗高粱蚜鉴定与评价研究

１９９６－１９９９年在田间自然感虫和人工接虫相结合的条件下,对１２６６份高粱种质资源进行了高梁抗蚜性鉴定,筛选了９份高抗材料和２３份抗性材料,对这批材料同步进行了高粱黑穗病、高粱靶斑产现任玉米螟等抗性鉴定,筛选出了１３份抗高粱蚜瘘抗其它病虫害的双抗或多抗材料 。     

高粱种质资源抗高粱靶斑病鉴定与评价

1996～1999年在田间人工接种诱导发病的条件下，对1476份高粱种质资源和40个高粱杂交种或杂交组合进行了抗高粱靶搬病抗性鉴定。从中鉴定筛选出419份抗高粱靶搬病的种质资源，9个高抗和7个抗高粱靶搬病的高粱杂交种或杂交组合。     

大豆蚜虫抗性鉴定技术及抗性资源筛选

探讨人工气候箱和田间网室2种接蚜鉴定方法对大豆蚜虫的鉴定效果,并用田间网室鉴定方法对109份黑龙江省栽培大豆进行蚜虫抗性分析.结果表明:田间网室和人工气候箱均能准确鉴定大豆品种的抗性;所有鉴定品种间抗性差异明显,但是没有免疫和高抗品种,抗性材料37份,占总检测材料的33.9%.     

大豆对食叶性害虫的抗性与农艺性状的关系

在田间自然虫源条件下,对５０３份国内外大豆种质资源抗虫性进行了鉴定,筛选出对本地大豆食叶性害虫表现抗性的资源５份,感性的资源６份。研究了其中１８２份种质资源抗虫性与农艺性状的关系,结果表明,大豆抗虫性与开花期、成熟期、结荚习性、茸毛色、茸毛密度、茸毛长短、种皮色、单株分枝数、茎秆粗度等性状显著相关,而与花色、叶色、叶形、生育习性、株高、底荚高、百粒重、单株荚数、粒形、茸毛着生状、茸毛粗细等性状相独立。     

花生种质资源抗花生青枯病鉴定

通过对3381份(国内2257,国外1124份)花生种质资源的田间自然病圃和人工接种鉴定,共获得高抗花生青枯病的种质资源55份,中抗43份。其中国内资源高抗的50份,中抗的39份,国外资源高抗的5份,中抗4份。不同类型的资源以及同一类型不同地区来源的资源其抗性表现差异极大。并筛选出一批经济性状优良的高抗种质。     

转基因抗虫性水稻恢复系选育及特性分析

将优质抗稻瘟病水稻恢复系成恢177与转基因水稻Bt明恢63杂交并回交1次,采用PCR分析、试纸条检测、室内和田间人工接虫鉴定抗虫性,并结合系谱法选择农艺性状,病圃接种鉴定稻瘟病抗性,育成具转基因抗虫性的水稻新恢复系Bt5198。采用离体茎秆法接种二化螟卵块,新恢复系Bt5198和Bt明恢63的幼虫死亡率均为100%。在田间人工接虫条件下,该恢复系对二化螟和三化螟均表现高抗,与4个不育系配制的杂种F1仍保持良好的抗虫性,且杂种优势明显。两年稻瘟病抗性鉴定结果表明,新恢复系Bt5198的叶瘟和颈瘟抗性水平与成恢177相当,明显优于Bt明恢63。Bt5198的种子发芽率和花粉量与成恢177相当,Bt基因导入水稻恢复系不会对种子生活力和制种产量造成显著影响。在无选择标记基因的转基因后代中,结合利用试纸条检测和室内、田间人工接虫鉴定是筛选Bt基因抗虫性的有效方法。     

国外引进抗草甘膦棉花种质资源田间鉴定及其特性分析

为研究棉花种质资源对草甘膦的抗性，在苗期采用叶片涂抹药剂的方法，用41%（质量分数）草甘膦异丙胺盐水剂对国外引进的4份棉花种质资源进行田间草甘膦抗性鉴定。同时，对4份种质资源的农艺及品质性状进行了调查。抗性鉴定结果表明：在3 000 mL·hm^－2的推荐用量下，4份种质资源均有很好的抗性；制剂用量增大1倍后，4份种质资源出现不同程度的药害反应，其中18TJ2抗性好，达到高抗水平。田间性状调查结果表明：18TJ2、18TJ3、18TJ4矮秆特征明显，18TJ4属于高衣分种质资源，18TJ3属于低衣分种质资源，18TJ1、18TJ2、18TJ3的纤维断裂比强度较优。     

导入抗真菌基因的Bt棉花种质对黄萎病、棉铃虫的抗性初报

对62份导入抗真菌基因的Bt棉花种质材料的抗虫性及抗病性进行初步鉴定,鉴定结果为47份材料高抗棉铃虫,38份材料抗黄萎病,高抗棉铃虫同时抗黄萎病的材料33份.鉴定结果表明,导入抗真菌基因后,在耐黄萎病的基础上,大部分材料转为抗至高抗,同时对棉铃虫的抗性也有所增强.     

大豆对食叶性害虫抗性机制的研究

１９９３～１９９６年,利用田间自然虫源,以叶面积损失率为指标,进一步鉴定了从６７２４份大豆资源中筛选出的４６份抗感材料对食叶性害虫的抗性表现。从中选出３份抗虫和３份感虫的材料,用以研究自然虫源下豆卷叶螟、斜纹夜蛾、大造桥虫和筛豆龟蝽的产卵选择性,并在实验室和网室人工接虫条件下,研究了抗感材料对斜纹夜蛾的抗虫性机制。结果表明,田间自然虫源下抗感材料以叶面积损失率为指标的综合抗性相差显著;４种重要食叶性害虫在抗虫品种上的产卵量较少;用抗虫品种叶片饲养斜纹夜蛾幼虫,表现为食量减少、体重变小、死亡率增加、历期延长以及蛹重减轻等,而对蛹死亡率和蛹历期的影响不明显。大豆对食叶性害虫具有明显的排趋性和抗生性,尤以后者为重要。     

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.