水稻超高产育种的理论和方法

 水稻超高产育种是当前世界性的热门课题，也是难题。现在我国人口已近十二亿，水稻是我国粮食生产的大头。高产更高产，难度越来越大。它的超高产育种，既无现成的理论和方法可循，就只能摸索前进。本文试图将几十年来多少人的汗水心血所凝成的宝贵经验，全面加以分析整理，藉以进一步完善过去所提出的理想株形与优势利用相结合的大方向，优化性状组配以及杂交后代选择标准等理论和方法，以供国内外同行参考试用。     

The California rice cropping system: agronomic and natural resource issues for long-term sustainability

California rice is produced on approximately 200,000 ha mostly in the Sacramento Valley. The crop is planted in April/May and harvested in September/October. The growing season is characterized by a Mediterranean climate with negligible rainfall, high solar radiation, and relatively cold nighttime temperatures, thus yields may exceed 9 t ha⁻¹, 20% above the US average. California is a highly urbanized State with an affluent population demanding agricultural practices to be environmentally benign and food products to be safe for human health. This has contributed to a rigorous regulatory climate for plant protection chemicals thus increasing the cost of production. Likewise, the resource base is being challenged. Increased demand for clean potable water for urban expansion and the demand for environmental water compete with rice for limited supplies while raising cost. Production problems, such as straw management for cleaner air, weed resistance to herbicides, and the introduction of exotic pests also contribute to higher costs. The California rice industry is challenged by the increasing complexity of the rice production system to meet both the off-farm public demands and the on-farm need for higher productivity.     

Modelling and simulating commercial hot water blanching of potatoes

A method of applying the leaching model for hot water blanching to predict component losses during commercial scale potato processing was developed. The method involves characterizing an individual blancher to adjust the model to account for nonuniform mixing flow. The leaching model is based on the assumption that the water in the blancher is completely back mixed and the temperature and concentration are uniform throughout. The concentration of the blanch water for back mix flow was calculated using the mean blancher temperature. The blanch water concentration for nonideal flow (e.g., plug flow) corresponding to the temperature distribution was calculated. Using some combination of back mix and plug flow the blanch water concentration was calculated. Comparing the calculated and experimental values, a factor to adjust the model-calculated concentration to agree with the real value was determined. This factor then is used to correct future calculations made on this particular blancher with the model. Potassium is used as a key component because it is stable for sampling and analysis. However, the method should work for other components.     

长江中下游麦区小麦品质改良设想

长江中下游麦区是我国唯一的弱筋小麦优势产业带,该麦区的沿江、沿海地区适宜发展弱筋小麦,其他地区适宜发展中筋小麦.弱筋、中筋小麦品种的品质遗传改良是该麦区重要育种方向之一.目前该麦区虽然育成并推广了一批弱筋、中筋小麦品种,基本满足了生产上对优质小麦品种的需求,但还存在一定的问题.如新育成的弱筋小麦品质并不优于扬麦9号和宁麦9号,中筋小麦面筋含量和强度还需提高.针对存在的问题,提出该麦区小麦品质改良的3个设想:(1)利用高分子量谷蛋白亚基缺失,降低面筋强度,培育优质弱筋小麦;(2)利用优质高分子量麦谷蛋白亚基组合,改善蛋白质组分,提高面筋强度,培育优质中筋小麦;(3)利用Wx蛋白亚基缺失,培育弱筋和中筋兼用型小麦,使该麦区小麦品种在蛋白质含量和面筋含量偏高而不能作为弱筋小麦使用时,利用其优良的淀粉品质加工品质较优的面条.     

Key issues and challenges in whole wheat flour milling and storage

Whole wheat flour is increasingly popular as research continues to reveal the benefits of whole grains and the food industry offers more whole grain options for consumers. The purpose of this review is to address milling and shelf-life issues that are unique to whole wheat flour. No standard methods are available for whole wheat flour milling, resulting in very different bran particle sizes. Literature suggests that moderate bran particle size is the best for bread production, while small particle size is better for non-gluten applications. Shelf-life of whole wheat flour is shorter compared to white flour due to the presence of lipids and lipid-degrading enzymes. Lipolytic degradation leads to reduction in functionality, palatability and nutritional properties. Strategies to stabilize whole wheat flour have focused on controlling lipolytic enzyme activity and have marginally succeeded.     

不同方法从大豆不同组织中提取基因组DNA效果的比较

从大豆组织中获得高质量和足够产量的基因组DNA,是进行大豆分子生物学研究的基础.为进行大豆基因组的PCR,RAPD,SSR等分子生物学研究,分别以大豆种子和其叶片为实验材料,采用改良的SDS法和CTAB法对大豆基因组DNA进行了提取.对DNA的提取效果,采用紫外分光光度检测、琼脂糖凝胶电泳分析及DNA的限制性内切酶图谱分析进行了综合比较.结果表明,在以叶片为材料时,SDS法和CTAB法的大豆基因组DNA的提取效果差别不大,SDS法稍好于CTAB法.在以大豆种子为材料时,SDS法的提取效果明显优于CTAB法,SDS法可从大豆种子中提取到能够充分满足各种分子操作的高质量和数量的大豆基因组DNA.     

Conservation agriculture and smallholder farming in Africa: The heretics’ view

Conservation agriculture is claimed to be a panacea for the problems of poor agricultural productivity and soil degradation in sub-Saharan Africa (SSA). It is actively promoted by international research and development organisations, with such strong advocacy that critical debate is stifled. Claims for the potential of CA in Africa are based on widespread adoption in the Americas, where the effects of tillage were replaced by heavy dependence on herbicides and fertilizers. CA is said to increase yields, to reduce labour requirements, improve soil fertility and reduce erosion. Yet empirical evidence is not clear and consistent on many of these points nor is it always clear which of the principles of CA contribute to the desired effects. Although cases can be found where such claims are supported there are equally convincing scientific reports that contradict these claims. Concerns include decreased yields often observed with CA, increased labour requirements when herbicides are not used, an important gender shift of the labour burden to women and a lack of mulch due to poor productivity and due to the priority given to feeding of livestock with crop residues. Despite the publicity claiming widespread adoption of CA, the available evidence suggests virtually no uptake of CA in most SSA countries, with only small groups of adopters in South Africa, Ghana and Zambia. We conclude that there is an urgent need for critical assessment under which ecological and socio-economic conditions CA is best suited for smallholder farming in SSA. Critical constraints to adoption appear to be competing uses for crop residues, increased labour demand for weeding, and lack of access to, and use of external inputs.     

Effects of a late N fertiliser dose on storage protein composition and bread volume of two wheat varieties differing in quality

Wheat is an important source of energy and protein for humans all over the world and is mainly consumed in form of baked goods, for which a high baking quality is required. The main parameter for bread-making quality predictions of wheat flours is the grain protein concentration (GPC). Therefore, the GPC determines the value of the harvested wheat. Unfortunately, the GPC appears to be no longer an appropriate parameter for baking quality evaluation, given that, especially for high protein varieties, the correlation between GPC and bread volume is poor. A late N application is commonly used to increase GPC and enhance the bread-making quality of wheat flours. To minimise the environmental problems involved in the late use of N fertilisers, it is important to know how much N is necessary to achieve the desired effects. Therefore, in this study, the effects of two different doses of late N application on the GPC, as well as storage protein composition and bread volume were tested in two wheat varieties from different quality groups under field conditions in Germany. The findings of this experiment demonstrate that a low late N application appears to be sufficient to achieve a good baking quality of wheat flours. These results confirm the presumption that GPC is not a suitable parameter for bread-making quality predictions. As the relationships between the single storage protein fractions and bread volume were poor, it can be concluded that only the combined alterations within all gluten protein fractions explain the rise in bread volume.     

Optimization of the processing conditions and prediction of the quality for dyeing nylon and lycra blended fabrics

This paper is intended to determine the optimal processing parameters applied to the dyeing procedure so that the desired color strength of a raw fabric can be achieved. Moreover, the processing parameters are also used for constructing a system to predict the fabric quality. The fabric selected is the nylon and Lycra blend. The dyestuff used for dyeing is acid dyestuff and the dyeing method is one-bath-two-section. The Taguchi quality method is applied for parameter design. The analysis of variance (ANOVA) is applied to arrange the optimal condition, significant factors and the percentage contributions. In the experiment, according to the target value, a confirmation experiment is conducted to evaluate the reliability. Furthermore, the genetic algorithm (GA) is combined with the back propagation neural network (BPNN) in order to establish the forecasting system for searching the best connecting weights of BPNN. It can be shown that this combination not only enhances the efficiency of the learning algorithm, but also decreases the dependency of the initial condition during the network training. Most of all, the robustness of the learning algorithm will be increased and the quality characteristic of fabric will be precisely predicted.     

Soil solarization in various agricultural production systems

Soil solarization is a natural, hydrothermal process of disinfesting soil of plant pests that is accomplished through passive solar heating. Solarization occurs through a combination of physical, chemical, and biological mechanisms, and is compatible with many other disinfestation methods to provide integrated pest management. Commercially, it is used on a relatively small scale worldwide as a substitute for synthetic chemical toxicants, but its use is increasing as methyl bromide, the major chemical fumigant, is phased out due to its ozone-depleting properties. Solarization currently is an important and widespread practice for home gardeners. In production agriculture, the principal use of solarization (on a treated area basis), is probably in conjunction with greenhouse grown crops. Another application for which solarization has come into common use is for disinfestation of seedbeds, containerized planting media, and cold-frames. Around the world, solarization for disinfesting soil in open fields is being implemented at a relatively slow but increasing rate. It has been mainly used for commercial production in areas where air temperatures are very high during the summer and much of the cropland is rotated out of production due to excessive heat. As global concerns regarding environmental quality grow along with the human population in the 21st century, concepts such as solarization and other uses of solar energy in agriculture will likely become increasingly important.     

THE PROFITABLE USE OF GRASSLAND IN MILK PRODUCTION

The most profitable use of grass in feeding a dairy herd is considered. Provided that the quality of the grass and grass products is sufficiently high for it to be used for part of the production ration, it is possible either to maintain a larger herd by buying concentrates, or to keep a smaller herd, feed less concentrates and use part of the grass for production. The potential herd size will depend both on the level of concentrate feeding and on the milk yield of the herd.
When account is taken of the extra costs involved with larger herds (labour, capital charges and some variable costs) the optimum system depends on the level of milk yield. For herds yielding below 900 gallons average, the most profitable system is that which obtains the maximum production from grass. With herds of over 1000 gallons average it is more profitable to use concentrates for the production ration and to keep the maximum number of cows.     

大麦茎尖愈伤组织的诱导和植株高频再生

为明确大麦茎尖高频再生培养体系的影响因素,以大麦品种甘啤3号、甘啤4号和甘啤6号为材料,研究颖壳去除方法、灭菌处理方式、无菌苗的苗龄、茎尖切段的大小和位置以及外源激素(2,4-D)浓度对大麦茎尖愈伤组织培养和植株高频再生的影响。结果表明,大麦种子颖壳去除的最佳方法是将种子浸泡在30%的硫酸中,并置于水平摇床30℃、180r·min~(-1)摇动1h;同时发现参试品种中甘啤4号发芽率最高;75%的乙醇1.5min+2%的NaClO 15min的灭菌处理效果最好,其带菌率和发芽率与其他处理有显著差异,并且对种子伤害较小,幼苗整齐度较好,有利于无菌苗的培养;茎尖外植体愈伤组织的形成和植株再生频率与茎尖切段的位置和苗龄密切相关,3d苗龄、茎尖基部2mm处的切段效果最好;3mg·L~(-1) 2,4-D适宜愈伤组织的离体培养,在出愈率和植株再生率上差异显著,可以诱导出大量愈伤组织。     

Survey of Fura production in some northern states of Nigeria

The objective of research was to conduct a survey related to the production process for fura. Fura is a staple food for the Fulanis and Hausas. The single most important cereal grain for fura production is millet. A significant difference exists among respondents on the variety of millet chosen for fura production. A significantly greater proportion (p=0.05) indicated that `gero' is the variety in common use. Spices are indispensable as an ingredient in fura production with ginger being the single most important spice (p=0.01). The traditional pounding method for processing millet into flour is still very much used. The implication of this is highlighted and a possible solution of optimizing fura production process is recommended. Strictly speaking, fura is distributed with a minimum of packaging. The choice of suitable package provided protection during a generally short shelf-life and for local distribution. With increasing influence of advertising upon customers, small food processing enterprises making fura will have to improve the packaging and preservation of their products if they are to survive the competition.     

红麻系列新品种在福安的丰产性与栽培特性研究

本研究对引进的12份红麻新品种在福建福安进行多年多点丰产性对比试验鉴定和生产性对比示范，并分别以粤743，青皮3号为对照，结果表明，福红951、福红952、福红14号、福红11号、福红15号、金光无刺2号等6个品种，原麻产量比对照粤743增高14．4％-27％，其中福红3号、福红952、福红14号、福红15号比对照粤743增产20％以上；干茎产量比对照粤743增产9．15％-26％，其中福红3号、福红951、福红952、福红14号、福红15号比对照粤743增产16％以上。上述这几个品种是麻纺与造纸兼用的红麻优良品种。栽培特性研究表明，在福建福安以4月下旬播种比较有利于一播全苗，4月底至5月底为苗期，日平均生长量为1．8cm；6月初至7月中旬为红麻旺长期，日平均增长量达4．75cm，7月中旬-9月中旬为稳长期，日平均生长量为2cm。在栽培上宜在5月底重施旺长肥，7月中旬后酌施稳长肥，以满足高产群体对肥料的需求。     

Intelligent geographic information systems and integrated pest management

Research in integrated pest management (IPM) has resulted in the development of an immense knowledge base that requires computer-aided methodologies for integration, interpretation and delivery. Examined in this paper are four issues of concern to decision-making and problem-solving for IPM. First, the IPM enterprise is examined in the context of contemporary landscape ecology principles. The functional unit for IPM is defined to be the ecotope (a term intended to embody concepts of ecosystem functionality in the context of topographical dimension). A landscape consists of a mosaic of interacting ecotopes. The scope of IPM extends beyond forest and farm management and includes issues associated with environmental management. Second, the utility of geographic information systems (GISs) for IPM is considered. GISs add a new dimension to IPM in that they provide a mechanism for dealing with site-specific and spatially referenced data. The addition of methodologies from artificial intelligence expert systems, in particular, permits integration of qualitative knowledge of human experts with quantitative information that is the product of research. The resulting software system is termed an intelligent geographic information system, IGIS. This system allows for automated interpretation within and among landscape data themes. The product is an interpretative map or a tabular report. Third, utility of the IGIS approach is illustrated by an example involving habitat delineation for an endangered species, the Houston toad. In this example a simple rulebase is developed that defines habitat locations that would be suitable for the toad. Fourth, a concept and method for integrating the different types of knowledge available for IPM (published research results and reports, spatial and tabular databases, simulation models, and observations and experiences of human experts) is described. This software system, the knowledge system environment, retains the unique features of an IGIS but is more useful in that it employs the full measure of knowledge available from IPM. With new technology from computer science and concepts from information engineering, it has been possible to formulate a new conceptual model of IPM that incorporates both the information systems needed as well as the activities required for implementation of IPM.     

Development of drought-resistant cultivars using physiomorphological traits in rice

Drought is a major problem for rice grown under rainfed lowland and upland conditions, but progress in breeding to improve drought resistance has been slow. This paper describes patterns of water-stress development in rice fields, reviews genetic variation in physio-morphological traits for drought resistance in rice, and suggests how knowledge of stress physiology can contribute to plant breeding programmes that aim to increase yield in water-limiting environments. To provide a basis for integrating physiological research with plant-breeding objectives we define drought resistance in terms of relative yield of genotypes. Therefore, a drought-resistant genotype will be one which has a higher grain yield than others when all genotypes are exposed to the same level of water stress.A major reason for the slow progress in breeding for drought resistance in rice is the complexity of the drought environment, which often results in the lack of clear identification of the target environment(s). There is a need to identify the relative importance of the three common drought types; early-season drought which often causes delay in transplanting, mild intermittent stress which can have a severe cumulative effect, and late stress which affects particularly late-maturing genotypes. In addition, in rainfed lowland rice, flooded and non-flooded soil conditions may alternate during the growing season, and affect nutrient availability or cause toxicity.Several drought-resistance mechanisms, and putative traits which contribute to them, have been identified for rice; important among these being drought escape via appropriate phenology, root characteristics, specific dehydration avoidance and tolerance mechanisms, and drought recovery. Some of these mechanisms/traits have been shown to confer drought resistance and others show potential to do so in rice. The most important is the appropriate phenology which matches crop growth and development with the water environment. A deep root system, with high root length density at depth is useful in extracting water thoroughly in upland conditions, but does not appear to offer much scope for improving drought resistance in rainfed lowland rice where the development of a hard pan may prevent deep root penetration. Under water-limiting environments, genotypes which maintain the highest leaf water potential generally grow best, but it is not known if genotypic variation in leaf water potential is solely caused by root factors. Osmotic adjustment is promising, because it can potentially counteract the effects of a rapid decline in leaf water potential and there is large genetic variation for this trait. There is genotypic variation in expression of green leaf retention which appears to be a useful character for prolonged droughts, but it is affected by plant size which complicates its use as a selection criterion for drought resistance.There is a general lack of drought related research for rice in rainfed lowland conditions. This needs to be rectified, particularly considering their importance relative to upland conditions in Asian countries. We suggest that focussing physiological-genetic research efforts onto clearly defined, major target environments should provide a basis for increasing the relevance of stress physiology and the efficiency of breeding programmes for development of drought-resistant genotypes.     

A Statistical Framework for Selecting Natural Fibre Reinforced Polymer Composites Based on Regression Model

Material selection is an important stage in the development of products from composites process of automotive component application. Numerious different Multi-Criteria Decision-Making tools have their own strenghts and limitations. This paper presents a framework for material selection of natural fibre reinforced polymer composites by using statistical approach. The framework is developed using statistical methods which are simple, multiple and stepwise regression for the material selection process. The performance of potential material is investigated by a statistical analysis such as coefficient of correlation, coefficient of determination and analysis of variance. A case study to select the best composite of parking brake lever is applied to this framework. End results revealed that kenaf reinforced polypropylene is the best candidate for construction of automotive parking brake lever component. The best possible of statistical model for material selection of the composite can be referred by design engineer in composite industry for a multiple application. Moreover, the proposed framework is an aid to help engineers and designers to choose most suitable material.     

FARMERS' REASONS FOR NOT ADOPTING CONTROVERSIAL TECHNIQUES IN GRASSLAND FARMING

It is commonly said that'resistance to change' is a basic factor preventing farmers from adopting new techniques, but such a statement depends on an external judgement as to the suitability of the technique studied for the farmer. In a recent survey, farmers were asked to give their reasons for not taking up recommended techniques for grassland farming, and these reasons are examined. In some cases it is clear that the farmer has no good reason for not using the technique except that he dislikes it, and differences between techniques in this respect are discussed.     

橡胶树胶乳中硫醇功能以及模式植物中硫醇合成途径研究进展

天然橡胶是一种用途广泛的天然高分子化合物。限制胶乳产量的因素之一是排胶持续时间,如何延长排胶持续时间一直是排胶生理和割胶技术研究的主要问题。研究发现,割胶后乳管中能产生大量的活性氧,活性氧使黄色体膜氧化破裂是导致胶乳在乳管中原位凝固的主要原因之一。硫醇是乳管细胞中的一类抗氧化剂,具有延迟胶乳凝固的作用,与排胶持续时间密切相关。因此,硫醇的代谢途径成为目前的研究热点。本文总结了橡胶树硫醇功能以及模式植物中硫醇合成关键酶基因研究进展,旨在为进一步研究橡胶树硫醇合成途径关键基因提供指导。     

玉米抗旱育种

干旱是世界、也是我国许多玉米种植区限制产量的主要因素,培育抗旱玉米品种是解决这一问题的根本途径之一.在玉米抗旱育种中,正确选定目标性状是十分重要的.CIMMYT在玉米抗旱育种中以ASI(Anthesis-silking Interval)作为选择性状之一进行群体改良,并已育出一批抗旱玉米群体.描述了抗旱玉米的理想型,并讨论了利用分子生物技术于玉米抗旱育种中的问题.