野生一粒麦与普通小麦不同绿色器官光合特性和叶绿体结构特征

对野生一粒麦(T.boeoticum)和普通小麦品种品七(T.aestivum.cv.Pin7)开花期不同绿色器官光合速率(Pn) 、 色素含量、 PSII活性及叶绿体超微结构进行了考察.结果表明:野生一粒麦各器官(旗叶叶片、叶鞘、穗下节间、 穗)的光合速率均明显高于栽培品种品七,这与各器官具有较高的叶绿素含量和较多的叶绿体基粒片层数目有密切关系.     

pBⅠ121载体酶切位点添加及拟南芥Na~+/H~+逆向转运蛋白基因表达载体的构建

对pBI121载体GUS基因后的终止子序列(SacⅠ-EcoRⅠ)通过PCR扩增法进行了酶切位点的添加,即在SacⅠ后添加了XhoⅠ、在EcoRⅠ前添加了KpnⅠ。序列分析发现,两个酶切位点的添加是成功的,但扩增的终止子序列与原序列的同源性间有差异,即有4个碱基发生了变异,特别是第17个碱基位点出现了缺失。利用绿色荧光蛋白(GFP)对添加酶切位点载体进行了终止子活性的检测,结果发现,它与携带GFP的pBI121载体一样,GFP基因能正常表达,说明pBI121载体终止子序列酶切位点的添加是成功的。利用改造后的载体(pBI121-GZ)构建了CaMV35S启动子驱动AtNHX1基因的植物表达载体。     

普通野生稻(Oryza rufipogon Griff)花药培养研究——Ⅰ.提高花粉愈伤组织诱导率和绿苗分化率的研究

对79份采自广西不同地理环境的不同类型的普通野生稻进行了花药培养研究,发现不同类型材料的花培力有较大的差异,有41个编号的材料得到花粉绿苗。试验结果表明:孕穗期施复合肥料不仅提高了供体植株的营养水平,而且也明显地提高了花粉愈伤组织诱导频率。接种前稻穗用6—8℃低温预处理8—12天,愈伤组织诱导率和绿苗分化率可提高     

小麦灌浆后期青枯骤死与体内活性氧代谢关系的研究

小麦灌浆后期遇到“V”字型温度剧烈变化，可导致旗叶的还原型谷胱甘肽（GSH）、还原型抗坏血酸（ASA）含量下降，过氧化氢酶（CAT）活性降低，膜脂过氧化产物丙二醛（MDA）含量增加，细胞膜透性增大，外部形态表现为青枯骤死症状，千粒重明显降低。“V”字型温度变化导致体内活性氧清除能力降低、膜脂过氧化作用加剧，可能是     

High yield potential,shuttle breeding,genetic diversity,and a new international wheat improvement strategy

The main elements of the international wheat improvement program of the Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT), also known as the International Maize and Wheat Improvement Center, have been shuttle breeding at two contrasting locations in Mexico, wide adaptation, durable rust and Septoria resistances, international multisite testing, and the appropriate use of genetic variation to enhance yield gains of subsequently produced lines. Such an approach yielded successes known collectively as the Green Revolution. However, at the beginning of the 21st century, this “cultivar assembly line” approach needs fine tuning to address crop needs under increasingly adopted resource conserving practices, as well as those related to nutritional requirements of the end-users. International wheat improvement will therefore focus on the targeting of traits in respective mega-environments, and the use of participatory methods, especially in marginal environments. The main features of this wheat improvement strategy include the introduction of new and novel sources of genetic variation through wild species, landraces, and, potentially, the use of transgenes for intractable traits. This variation will be combined using international shuttle breeding, and increased breeding efficiency will be achieved through marker-aided methods, more targeted use of crop physiology, plant genetics, biostatistics, and bioinformatics. Likewise, CIMMYT will increase its focus on the needs of end-users by emphasizing regional efforts in participatory research and client-oriented plant breeding.     

绿茶杀青叶温控制系统的研究

在绿茶杀青工艺参数研究的基础上，用控制加热介质温度的方法来达到控制叶温度变化，建立了一套计算机控制系统，为今后茶叶生产自动化提供了基础     

低温对诱导小麦未成熟胚愈伤组织出愈率的影响研究

试验研究低温处理对诱导小麦未成熟胚愈伤组织出愈率结果表明 ,6h短时间低温处理可显著提高其出愈率 ,比对照增加 1 4 3倍。随处理时间的延长其出愈率逐渐降低 ,18h后其出愈率又渐增 ,低温处理 30h时其出愈率显著高于对照 ,为对照的 1 4 1倍。     

Seeding vs. vegetative propagations of the stem-nodulating green manure Sesbania rostrata

Summary Ratooning and stem cutting were compared with seeding in order to reduce the amount of seeds of Sesbania rostrata for green-manure growth. Both methods increased the biofertilizer yield highly significantly within a 6-week growth period.     

Physico-chemical properties of commercial composts varying in their source materials and country of origin

Composting is a partially controlled bio-oxidative process through which highly heterogeneous organic matter (OM) in its solid-state transforms into a humified material. The variability of the OM undergoing composting makes compost research a great challenge. Our purpose was to define chemical and plant response characteristics of a variety of composts, grouped based on their major source materials. Thirty-seven commercial composts were collected from France, Greece and the Netherlands. When grouped by country of origin, significant differences were found in %OM, %C, %N, dissolved organic carbon (DOC) concentration, electrical conductivity (EC) and NO₃ concentration. These differences may be attributable to source materials or local regulations and quality control measures. When the composts were classified into 7 groups by their source materials: wood, green, manure, grape marc (GM), oilcake, spent mushroom substrate and municipal solid waste-based composts, significant differences between groups were found in %OM, %C, %N, DOC, pH, EC, NO₃ and soluble sugars. Extracts of composts from all groups, except GM and oilcake had absorbance in the UV and visible range that was linearly correlated with DOC. GM and oilcake compost extracts had lower absorbances and distinctly lower specific UV absorbance (SUVA). Diffuse reflectance infrared Fourier Transform (DRIFT) spectra of the composts from different source groups also exhibited distinct group features (e.g. the ratio of polysaccharide to aliphatic peak intensity), whereas NMR spectra did not. Cucumber plants grown on manure-based composts had greater fresh weight than those grown on other composts. Plants grown on oilcake and GM composts exhibited low fresh weight. The difference in characteristics of the oilcake and GM composts may be a result of their unique chemical composition which slows their degradation. It may also be related to their relatively low degree of maturity, which is a consequence of their slow degradation.     

Influence of phosphorus or phosphorus-potassium fertilization on biomass and dinitrogen fixation of the stem-nodulating green-manure legume Sesbania rostrata in different marginally productive wetland rice soils

The performance of Sesbania rostrata varies widely from site to site. This makes it difficult to predict the N yield and biomass of this plant in marginally productive soils, and to arouse the interest of farmers in green manure technology. Three consecutive pot experiments were conducted in a greenhouse at the International Rice Research Institute (IRRI) to evaluate growth, nodulation, N₂ fixation (C₂H₂ reduction assay and ¹⁵N dilution method), and N yield of 6-week-old S. rostrata on 13 physicochemically different wetland rice soils of the Philippines and on three artificial substrates. The performance of S. rostrata on the unfertilized controls was compared with two fertilizer treatments containing either P (100 mg P kg^-1 dry soil) or P+K (100 mg P kg^-1 and 200 mg K kg^-1 dry soil). In the control soils and substrates, the N yield of S. rostrata varied between 20 and 470 mg N per pot, with the N rate from N₂ fixation ranging between 0 and 95%. In three of the nutritionally poor soils even Mn toxicity symptoms apparently occurred with S. rostrata. P application alleviated these symptoms and increased the overall N yield considerably, mainly through increased biological N₂ fixation. An additional increase in N yield was obtained by the PK treatment. Multiple regression analysis between soil characteristics and the N yield of S. rostrata showed that the original level of P (Olsen-extracted) and Mn in the soil accounted for 73% of the variance in biomass production by S. rostrata among the unfertilized soils and substrates.