Changes in NMR Relaxation of Rice Grains,Kernel Quality and Physicochemical Properties in Response to a High Temperature after Flowering in Heat-Tolerant and Heat-Sensitive Rice Cultivars

Abstract

Rice productivity is related to the ability of plants to adapt to heat stress. The heat-tolerant cultivars ‘Nikomaru’ and ‘Chikushi 64’ and heat-sensitive cultivar ‘Hinohikari’ were grown at 30ºC and 25ºC for 49 days after flowering. At 30ºC, only a few white immature kernels were produced in ‘Nikomaru’ and ‘Chikushi 64’, but about 22% of grains had immature kernels in ‘Hinohikari’. The high temperature(30ºC) caused no significant changes in grain dry weight, water content, and the NMR T₁ value during the early ripening stage in ‘Nikomaru’ and ‘Chikushi 64’. It also did not affect grain development, especially with respect to the nucellar epidermis, in ‘Nikomaru’ and ‘Chikushi 64’, but caused clear cessation of development of the nucellar epidermis at 14 days after flowering in ‘Hinohikari’. In addition, high temperature decreased the amylose content and increased hardnessvs. adhesion ratio of cooked rice in both ‘Nikomaru’ and ‘Chikushi 64’ resulting a softer, less sticky texture, but not in ‘Hinohikari’. The maximum viscosity and breakdown values were increased, and final viscosity decreased at 30ºC in all three cultivars. These results suggested that starch in the endosperm of grains changed from a fluid state to a doughy state more slowly in ‘Nikomaru’ and ‘Chikushi 64’ than in ‘Hinohikari’, in which the water content and NMR relaxation time decreased, and transported assimilates accumulated slowly during grain development.     

响应面法优化米口袋总黄酮的超声提取工艺

旨在采用超声波辅助法提取米口袋中总黄酮并对工艺进行优化。在单因素实验的基础上,确定料液比、超声温度、超声功率、超声时间4个因素的Box-benhnken的实验设计。以总黄酮的提取率为响应值,采用响应面法优化米口袋总黄酮的提取工艺,建立并分析各因素与指标值的数学模型。最佳工艺参数为:料液比1:40 g/m L,超声温度45℃,超声功率300 W,超声时间60 min,总黄酮提取率理论值为8.08%,实际值为8.22%,相对标准偏差为0.33%。本实验方法具有操作简便、提取时间短和成本低等优点,可为后期米口袋的研究提供理论依据。     

Influence of Extreme Management on Decomposable Soil Organic Matter Pool

Basing on two long-term model experiments (microplots as well as greenhouse pot experiment) the influence of extreme management on a very easily decomposable pool of soil organic matter (SOM) was measured. The carbon content (C hwe ) of a hot water extractable pool of SOM was used as an indicator for the decomposable C pool. This parameter reflects both the dynamics of the amount of decomposable organic C pool and the different transformation conditions in case of the pot experiment (outside versus inside the greenhouse). Depending on soil type and both the total and decomposable organic matter level at the starting point of the experiments we can observe differences in the decreasing speed of the decomposable C pool: in the soils having a high level of SOM at starting point C hwe pool decreases more rapidly compared to the soils unfertilized or in case of the only P and K treatment of the Static Fertilization Experiment at the beginning of the pot experiment. At least we can observe a difference in decreasing intensity of this C hwe pool when comparing different soil types.     

Gene Expression of Enzymes for Starch and Sucrose Metabolism and Transport in Leaf Sheaths of Rice (Oryza sativa L.) during the Heading Period in Relation to the Sink to Source Transition

Abstract

Leaf sheaths of rice plants are known to temporarily accumulate starch prior to heading, which is subsequently remobilized and transported into the panicle after heading. We investigated the time course for both carbohydrate content and steady state mRNA levels of enzymes related to starch and sucrose metabolism in the rice leaf sheath (Oryza sativa L. cv. Nipponbare). Leaf sheaths from the second leaf below the flag leaf accumulated high levels of starch before heading but they rapidly decreased after heading. In contrast, the flag leaf sheath did not accumulate as much starch. In the second leaf sheath, the mRNA levels of enzymes involved in starch synthesis, ADP glucose pyrophosphorylase (EC 2. 7. 7. 27), soluble starch synthase (EC 2. 4. 1.21) and branching enzyme (EC 2. 4. 1. 18) were high before heading, which coincided with rapid accumulation of starch. The mRNA levels of sucrose synthesis enzymes, cytosolic FBPase (EC 3. 1. 3. 11) and sucrose phosphate synthase (EC 2. 4. 1. 14), and the sucrose transporter (OsSUTI) increased at the time of heading, which was largely coincident with a decrease in the mRNA levels of starch synthesis enzymes. In the flag leaf sheaths, changes in mRNA levels of starch synthesis enzymes were not pronounced, however mRNA levels of sucrose synthesis enzymes and the sucrose transporter showed a clear increase throughout the heading period. The different characteristics observed between the two leaf sheaths will be discussed in relation to the sink to source transition.     

Effects of Soil Temperature on Growth and Root Function in Rice

Abstract

The objective of this study was to clarify the effects of soil temperature in the stage from late tillering to panicle initiation (SI) and during the grain-filling stage (SII) on grain setting, dry matter production, photosynthesis, non-structural carbohydrate (NSC), xylem exudation and abscisic acid (ABA) levels in rice (Oryza sativa L. cv. Koshihikari). Rice plants were exposed to four different soil temperatures during SI or SII: 17.5, 25, 31.5 and 36.5°C (ST18, ST25, ST32 and ST37, respectively). The yield, yield components, grain filling and quality in SI were negatively influenced by high soil temperature of 37°C. On the other hand, there was no significant difference in those characters among temperature treatments in SII. The root/shoot ratio was smallest in the ST37 plants in both SI and SII, mainly due to their lighter root weight. At 7 days after initiation of treatment (DAT) in both SI and SII, the photosynthetic and xylem exudation rate tended to increase slightly as soil temperature increased up to 32°C. At 21 DAT, however, the photosynthetic rate was lowest in ST37, with concurrent decrease of diffusion conductance and SPAD value. In addition, decrease of NSC concentration in stem and xylem exudation rate, and increase of ABA level in leaves and xylem exudate were observed in ST37 plants at 21 DAT. These results suggested that high soil temperature before heading especially influenced yield, grain quality and plant growth. Possible mechanisms of the effect of soil temperature are discussed.     

一种侵染桃树的烟草花叶病毒(TMV)的分离鉴定

 从北京地区具有红叶及叶片侧脉失绿等综合症状的桃病株上分离到一种杆状病毒分离物P-1,初步鉴定为一TMV株系;制备抗血清微量沉淀法测定效价为1:1024,并应用于田间样品检测;提纯P-1分离物回接毛桃实生苗后,在上部叶片出现脉间失绿症状,用P-1抗血清作ELISA检测为阳性,肯定了TMV对桃的侵染及致病作用。     

Pigeonpea Nutrition and Its Improvement

Abstract

Pigeonpea (Cajanus cajan [L.] Millsp.), known by several vernacular and trade names such as red gram, tuar, Angola pea, Congo pea, yellow dhal and oil dhal, is one of the major grain legume crops of the tropics and sub-tropics. It is a favorite crop of small holder dryland farmers because it can grow well under subsistence level of agriculture and provides nutritive food, fodder, and fuel wood. It also improves soil by fixing atmospheric nitrogen. India by far is the largest pigeonpea producer where it is consumed as decorticated split peas, popularly called as ‘dhal’ In other countries, its consumption as whole dry seed and green vegetable is popular. Its foliage is used as fodder and milling by-products form an excellent feed for domestic animals. Pigeonpea seeds contain about 20-22% protein and appreciable amounts of essential amino acids and minerals. Dehulling and boiling treatments of seeds get rid of the most antinutritional factors such as tannins and enzyme inhibitors. Seed storage causes considerable losses in the quality of this legume. The seed protein of pigeonpea has been successfully enhanced by breeding from 20-22% to 28-30%. Such lines also agronomically performed well and have acceptable seed size and color. The high-protein lines were found nutritionally superior to the cultivars because they would provide more quantities of utilizable protein and sulfur-containing amino acids.     

Enhanced micropropagation of Dendrobium huoshanense C.Z. Tang et S.J. Cheng through protocorm-like bodies: The effects of cytokinins,carbohydrate sources and cold pretreatment

The effects of cytokinins, carbohydrate sources and cold pretreatment on the conversion of protocorm-like bodies (PLBs) to shoots were investigated for the enhancement of micropropagation of Dendrobium huoshanense C.Z. Tang et S.J. Cheng, an endangered medicinal plant in China. The effects of cytokinins and carbohydrate sources on the conversion of PLBs to shoots depended on their types and concentrations. The best results in terms of shoot development from PLBs occurred on 1/2 MS medium supplemented with 20 μM kinetin and 10 g l⁻¹ maltose. Cold pretreatment at 10 °C for 1–2 weeks significantly enhanced the conversion of PLBs to shoots, and over 1300 shoots were obtained from one gram of PLBs after 3 months of culture. The developed shoots were rooted on growth regulator-free MS medium supplemented with 8 g/l banana paste to give complete plantlets, which were successfully acclimatized with a survival rate of approximately 65%. The results indicate that a suitable cold pretreatment (10 °C for 1 week) followed by the use of 20 μM kinetin and 10 g/l maltose in 1/2 MS medium would produce a large number of shoots from PLBs for plantlet regeneration of D. huoshanense.     

中国对虾杂交优势对自然感染白斑综合征病毒的抗病力分析

中国对虾杂交优势对自然感染白斑综合征病毒的抗病力分析=Analysis of the resistance of heterosis in Fenneropenaeus chinensis to natural infection with white spot syndrome virus ［刊，中］/李素红（中国水产科学研究院黄海水产研究所，青岛 266071)，张天时，孟宪红，孔杰//水产学报，—2007，31(1).-68～75 一个包括42个全同胞家系的中国对虾选育群体，荧光标记后每个家系各取40尾健康个体混养，自然发病并确认感染白斑综合征病毒(white spot-syndrome virus，WSSV)。发病1周后将所有个体取出，统计各家系的存活率，并对活体利用巢式聚合酶链式反应(polymerase chain reaction，PCR)进行WSSV检测。对存活率进行分析，结果显示：4个家系的存活率在60％以上，7个家系的存活率在20％以下；存活率与第一次扩增阳性率、第二次扩增阳性率呈不显著负相关。第一次扩增阳性率与第二次扩增阳性率呈极显著正相关。结合两次扩增的阳性率分析得出：青岛野生群体内自交产生的一个家系和韩国群体养殖家系与乳山野生群体杂交产生的一个家系在抗病力上显著优于其它家系；经独立样本t检验表明，群体间交配组合的存活率差异不显著，因此家系选育可能是进行抗WSSV品种选育的重要途径。多重比较结果发现：韩国群体养殖家系(♂)与乳山野生群体(♀)杂交后代的存活率(56.20%±8.75%) 显著高于韩国群体养殖家系自交后代(22.50%±2.50%) (P<0.05)，说明该杂交后代在抗WSSV方面有一定程度的杂种优势。而韩国群体养殖家系 (♂)和乳山野生群体(♀)的杂交后代所表现的杂种优势(26.95)与其反交后代(3.85)差异显著。图3表5参15 关键词：中国对虾； 巢式PCR； 白斑综合征病毒 E-mail:kongjie@sina.com     

两种植物粗提物对桃蚜的杀虫活性研究

本试验主要以桃蚜为研究对象,通过喷雾法和浸渍法,进行河朔芫花氯仿提取物和地肤甲醇提取物对桃蚜杀虫作用的初步研究。获得结果为河朔芫花氯仿提取物使用喷雾法时24 h的致死中浓度为375.65 mg/L,使用浸渍法时24 h的致死中浓度为218.04 mg/L;地肤甲醇提取物用喷雾法时24 h致死中浓度为382.21 mg/L,浸渍法时24 h致死中浓度为303.21 mg/L。