Effect of Heat Stress on Grain Growth, Starch Synthesis and Protein Synthesis in Grains of Wheat (Triticum aestivum L.) Varieties Differing in Grain Weight Stability

The effect of heat stress on the components of grain weight was analysed in wheat ( Triticum aestivum L.) varieties differing in grain weight stability. The wheat varieties PBW154, Sonalika and Hindi62 were raised in the field (New Delhi, India; 77°12' E, 28°40' N, 228.6 m a.s.l.) at three dates of sowing: 19 November 1992 (DOS I), 14 December 1992 (DOS II) and 18 January 1993 (DOS III). The late-sown crop (DOS III) experienced 6–8 °C warmer temperatures during grain development than the crop sown at the normal time (DOS I). The heat susceptibility index (S) revealed that grain weight was less susceptible to heat in Sonalika and PBW154 than in Hindi62. Heat stress reduced both the grain growth duration (GGD) and the grain growth rate (GGR). The grain weight reduction in PBW154 and Sonalika was mainly due to a reduction in GGR, while that of Hindi62 was due to a reduction in GGD. In vivo studies on starch and protein synthesis in excised endosperm at 15, 25 and 35 °C revealed that both processes were more thermotolerant in Hindi62 than in PBW154. The grain starch content was stable in Hindi62 while that in PBW154 was significantly reduced under heat stress. The grain nitrogen content at maturity increased in both varieties under heat stress. It was concluded that the heat susceptibility of grain weight in Hindi62 was mainly due to a reduction in GGD, although GGR, starch and protein synthesis were more thermotolerant in developing grains of Hindi62 than in those of PBW154.     

腐蚀管道剩余寿命的性能衰减模型研究

管道在长期的运行过程中，由于介质和土壤的腐蚀性，管材的微塑性变形、结构转变和渗氢等。不仅会使管道出现各种腐蚀损伤，而且还存在着老化效应和氢化作用，导致管材的脆变并改变材料的塑性，使机械性质参数发生衰退，从管材性能衰减和腐蚀损伤角度研究了管道的剩余寿命，提出了根据结构承载能力的极限值确定塑性变形时工作寿命的方法，为了确定剩余使用寿命，对剪切损伤率和屈服性能比等概念进行定义，在掌握管材金属剪切损害率和屈服性能比的时间特性基础上，建立了剩余寿命计算模型。并给出了算例。     

干法生产UHT豆奶工艺技术研究及应用

以优质大豆为主要原料，经干法生产（大豆筛选、脱皮、高温灭酶、粗磨、超细研磨、浆渣分离）制得豆奶；根据QB／T2132产品分类要求（纯豆乳、调制豆乳、豆乳饮料），研究配方组成（大豆用量、加油量、乳化剂添加量）；采用UHT灭菌、复合塑料膜无菌灌装，常温下保质期达到30～90天.     

Ionic Ratios and Crop Performance: II. Effects of Interactions amongst Vanadium, Phosphorus, Magnesium and Calcium on Soybean Yield

Because vanadium (V) is easily reduced to a cationic form within plant cells, data from resin-extraction of soil were analysed for evidence of interactions between V and the resin-extractable concentrations of magnesium (Mg) and calcium (Ca) on soybean seed yield. Three varieties, 9091, 9061 and 704, were grown over a 3-year period in a corn–soybean–wheat rotation. Surface soil samples (0–15 cm) were extracted with ion-exchange resins, extracts were analysed by inductively coupled plasma methods (ICP), and the results were regressed against seed yield using SAS PROC STEPWISE analysis using forward selection, backward elimination and maximum R² routines. The seed yield of each variety showed a correlation with a unique set of resin-extractable concentrations of V, phosphorus (P), Mg and Ca, and the V:(V + P), Mg:(Mg + Ca), Mg:(Mg + 1000 V) and Ca:(Ca + 1000 V) ratios. Variety 9091 was most sensitive to the Mg:(Mg + Ca) ratio. Variety 9061 was most sensitive to extractable V and to the V:(V + P) ratio. Variety 704 was sensitive to extractable P, V and Ca and the Mg:(Mg + 1000 V) ratio. For variety 9091, Mg fertilization (not currently practised) may be an economical practice, whereas P fertilization of 704 may not be economical. Each regression technique varied slightly in identification of important factors in seed yield. Concentrations and ratios of resin-extractable elements in soil provide insights into optimal genotype selection and possible management alternatives for a given soil.     

猪肺炎支原体及其生物学研究进展

猪肺炎支原体是引起猪支气管肺炎的主要病原 ,严重危害着养猪事业的发展。虽然猪肺炎支原体的结构简单 ,但由于它对营养要求较高 ,故培养难度大 ,也是人们不能对其深入研究的一个主要原因。近年来利用克隆技术 ,对猪肺炎支原体从基因水平上进行了多种研究 ,已经取得了一些可喜成果。文章从它的生物学特性、荚膜结构、膜蛋白研究以及基因水平的研究等方面进行了综合性论述 ,并简明地指出了目前研究中存在的问题以及未来展望     

Narbon Vetch (Vicia narbonensis L.): A Potential Feed Legume Crop for Dry Areas in West Asia

Provision of feed supplies for the rapidly growing livestock population is essential in West Asia. Shortages can be alleviated by growing forage crops in the existing fallow lands.
Narbon vetch (Vicia narbonensis L.) is a leguminous species with high yield potential, drought tolerance and cold resistance. It could be used for grain and straw production as source for animal feed in dry areas. It is good source of protein with seeds contain 28 % protein yielding 364 kg per hectare protein, whilst straw contains 9 % protein and yields a similar amounts of digestible protein per hectare.
Nine promising lines of Narbon vetch developed at ICARDA were tested at two sites over four years under rainfed conditions. Since climatic conditions were considered to be of considerable importance, each site in each year was treated as a separate environment to give eight environments with annual rainfall varied from 195 to 504 mm.
Narbon vetch possessed high seedling vigour with rapid winter growth and negligible cold damage. Grain yield varied form 0.47 to 1.90 t/ha, with a harvest index varying from 30 to 40 %. The data indicated that below 300 mm rainfall the grain yield varied from 0.47 t/ha when rain fall was 195 mm to 1.4 t/ha when rainfall was 245 mm. Most of the lines had wide adaptation to dry areas in terms of both grain yield and stability. Climate, except early spring rains had little effect on biological and grain yields.     

大豆田苣荬菜综合防除技术研究

提出了大豆田恶性杂草—苣荬菜的综合防除技术体系：１）降低大豆在整个轮作体系中的比例，将苣荬菜消灭于禾谷类作物四；２）深翻抑制芽根的萌发；３）大豆前茬作物收获后秋季茎叶处理２．４－Ｄ丁酯，最佳用药量为０．８１～１．３５ｋｇ／ｈｍ２，最佳施药时期为１０月５～１０日；４）作为挽救措施可在大豆播后苗前施２．４—Ｄ丁酯，用药量为０．７２ｋｇ／ｈｍ２，并可与乙草胺、赛克津等常规大豆田除草剂混用．     

Acclimation abilities of three tropical rainforest seedlings to an increase in light intensity

Current practices in many nurseries involve the germination of tropical rainforest seedlings in shaded conditions and transferral, at a later date, to environments with greater light intensities. Determination of the ability of these seedlings to acclimate to increased light intensities will allow seedling stock to be processed with maximum efficiency within the nursery. The acclimation abilities of three species, Agyrodendron actinophyllum, Cardwellia sublimis, and Flindersia brayleyana, commonly found in north Queensland's rainforests were investigated in this study. These particular species are highly valued for their cabinet timber qualities and are being reared in nurseries for use in reforestation trials and programs in north Queensland. Seedlings were initially raised in greenhouse conditions under two layers of shade cloth (16% of full sunlight) and then transferred into full sunlight at three different ages (3 weeks, 10 weeks, 14 weeks). Upon transfer, organ ratios and the direction of dry matter distribution was determined for each species and age group. Approximately 3 months after the seedlings were transferred, the acclimation ability of each species and age group was then determined. Dry matter distribution was found to change with age, irrespective of light environment. Individuals within a species with larger root systems and thicker or more dense leaves had a greater acclimation ability than those with smaller root systems and thinner or less dense leaves. Furthermore, individuals within a species whose dry matter distribution upon transfer was directed towards developing a large root system, and a small photosynthetic area and mass, had a greater acclimation ability than those whose dry matter distribution was directed away from such morphologies. Awareness of these relationships allows a better understanding of seedling response to gap formation in natural forests, and also allows plant nursery operators to make a more informed decision about when to move seedlings to environments with a higher light intensity.     

黄淮夏大豆超高产育种模式的探讨

通过不同品种（系）和密度的超高产栽培试验，分析四因子和二因子的产量效应，各因子对产量贡献的大小为：亩荚数＞百粒重＞荚粒数。超高产育种和栽培的主攻方向是提高亩荚数，同步增加百粒重。黄淮超高产育种模式：亩荚数４６．７±５．３万，百粒重２２．４±２．６克，每荚粒数２．１８±０．１１个。     

春小麦蛋白质、脂肪、淀粉含量间的相关与回归分析

本文通过对20个春小麦品种(或品系)蛋白质、脂肪、淀粉百分含量间的相关、回归、协方差分析,表明蛋白质百分含量与淀粉百分含量间为极显著的负相关;脂肪百分含量与淀粉百分含量间为极显著的负相关;蛋白质百分含量与脂肪百分含量间为极显著的正相关。并建立了淀粉、脂肪、蛋白质百分含量间的回归方程。在同一试验条件下,各品种(或品系)蛋白质、脂肪、淀粉百分含量变异系数的大小,在一定程度上反映出各品种在品质性状上的纯合程度。变异系数愈小,表明纯合程度愈高;变异系数愈大,表明纯合程度愈低。因此,在那些变异系数较大的品种(或品系)中,可选出表型性状与原品种(或品系)基本相似,而在品质性状上却有较大提高的优质新品系。