基于BH20的温室无线监控系统

针对我国农业生产地域分散、偏远、现场信息获取困难以及架设有线网络成本高等特点,利用室外型无线覆盖模块(IAP)和点对点传输模块(BH20)等设备构建无线通信网络,并结合计算机控制、网络通信编程以及数据库等技术,开发了一套温室无线监控系统.测试结果表明,系统能够满足温室环境控制的要求.     

猪CD205特性的研究

CD205是树突状细胞(DCs)表达的一种细胞表面受体,在抗原捕获和递呈给内吞途径的过程中起重要作用。CD205除在DCs中表达外,还在胸腺上皮细胞中高表达,但在B细胞、巨噬细胞和T细胞中很少表达或几乎不表达。CD205在大多数动物中均有研究,但在猪中却鲜有报道。本试验对猪CD205及其在参与免疫反应的不同细胞和组织中mRNA的表达进行了研究。运用染色体步移扩增获得猪CD205的完整cDNA序列,长5175 bp,编码1723个氨基酸。Multi-domain structure分析发现,猪CD205与小鼠、人和牛的氨基酸同源性分别为74%、81%和85%。运用定量RT-PCR检测猪的正常组织和细胞,结果发现,CD205 mRNA在猪胸腺和郎格汉氏细胞中高表达。进一步研究猪CD205的特性,将有助于更好地了解该受体的作用,为深入研究抗原定向猪DCs提供参考依据。     

Beyond host specificity: the biotechnological exploitation of chitolectin from teratocytes of Toxoneuron nigriceps to control non-permissive hosts

Journal of Pest Science - The virulence factors (VF) that parasitoids use to regulate the growth and development of their hosts have potential as new events in transgenic plants. VFs are promising...     

Nitrate accumulation,productivity and photosynthesis of Brassica alboglabra grown under low light with supplemental LED lighting in the tropical greenhouse

Abstract

Vegetables are a large source of nitrate (NO₃^?) in our diet. As NO₂^? is toxic to humans, it is undesirable to consume vegetables with high NO₃^? content. Therefore, this study aimed to investigate the effect of supplementing of red- and blue-LED lighting to B. alboglabra grown in the tropical greenhouse in terms of moderating NO₃^? accumulation, improving photosynthesis, and enhancing productivity. All plants were grown hydroponically in full nutrients under prevailing greenhouse conditions for 20?days (full sunlight). Thereafter, plants were subjected to three different light treatments for 12?days: full sunlight, shade, and shade supplemented with LEDs. The average midday photosynthetic photon flux density (PPFD) during the light treatment periods were 220?μmol m^?2 s^?1 (full sunlight), 55?μmol m^?2 s^?1 (shade), and 220?μmol m^?2 s^?1 (shade supplemented with LEDs). Shoot nitrate (NO₃^?) concentration increased significantly in plants grown in the shade. However, shoot NO₃^? concentration was reduced when plants were supplemented with red- and blue-LED lighting. Photosynthetic CO₂ assimilation, stomatal conductance, and productivity also improved in these plants. Our results suggest that supplemental red- and blue-LED lighting in a tropical greenhouse during periods of cloudy and hazy weather could improve productivity and nutrient quality of Chinese broccoli.     

Occurrence of blossom‐end rot in tomato as a function of calcium dose in the nutrient solution and air relative humidity

The effects of different calcium (Ca) concentrations in the nutrient solution and of air relative humidity (RH) on the Ca levels and on the incidence of blossom‐end rot in tomato fruit cv. Jumbo were studied. The experiment was conducted in a greenhouse under hydroponic conditions using a modified Hoagland solution containing different Ca concentrations (0.2, 2.5, 5.0, 10.0, 15.0, and 20.0 mm L^‐1) which represented the different treatments. The trial was conducted in a fully randomized design with three replications, with Ca doses representing the plots and environments with high and low RH the subplots. The fruits of the second and third clusters were used, with two fruits per cluster, one maintained at high (90±5%) and the other at low (40±5%) RH. The fruits were picked after full ripening. A greater Ca accumulation was observed in fruits submitted to low RH with this accumulation occurring at all Ca levels in the solution. In the treatment with 100 mg Ca L^‐1, the plants died and did not reach fructification. The fruits of plants treated with 100 mg Ca L^‐1 and submitted to low RH had blossom‐end rot although their Ca levels were higher than those detected in the fruits of this treatment submitted to high RH. At this Ca dose, the seeds were small, malformed, and black. Our results show that fruit kept at low RH had higher Ca accumulation although the excessive water loss from tissues may lead to blossom‐end rot when low Ca doses are supplied to the plants.     

In Vitro Digestion of RS4‐Type Resistant Wheat and Potato Starches,and Fermentation of Indigestible Fractions

RS4‐type resistant wheat starch (RWS) and resistant potato starch (RPS) were subjected successively to in vitro digestion with pepsin and pancreatin‐bile, and the indigestible residues (82.1% db and 74.1% db, respectively) were recovered and subsequently fermented by in vitro techniques using fresh human fecal microbiota as inoculum. Scanning electron microscopy of the indigestible residues showed surface erosion on the residual granules. Total gas production during the in vitro fermentation increased almost linearly over time with the two resistant starches exhibiting similar gas production rates, as well as a similar rate of production of total short‐chain fatty acids (SCFA). The indigestible fractions from both starches produced acetate as the major SCFA and relatively higher levels of butyrate than propionate, but wheat starch tended to produce more butyrate over time than potato starch. Fractional molar ratios of acetate, propionate, and butyrate from the RWS and RPS were 0.586:0.186:0.228 and 0.577:0.200:0.223, respectively. The calculated caloric contributions of the RWS and RPS are ≈33% lower than for unmodified starch and are comparable to those reported in the literature for RS2 and RS3 high‐amylose maize starches.     

聚合草青枯病的发生规律及病原菌的研究

 高产优质饲料聚合草的青枯病,是七十年代发现的一种细菌性病害,分布在我国南方诸省,六至七月份为流行期,发病率一般为10~30%;严重地区高达90%以上,可形成毁灭性病害。该病侵害植株的维管束,使叶片青枯萎蔫和根部腐烂而死亡。对分离自病根的细菌,经形态、培养特征、生理生化特性、血清学反应及致病性等的鉴定,确认为青枯假单孢菌(Pseudomonas Solanacearum Smith),属于生理小种1(Race 1),生物型Ⅲ(BiotypeⅢ)。所致病害为聚合草青枯病。     

稻鱼共生系统的推广潜力分析——以中国南方10省为例

稻田浅水环境为许多水产动物提供了生境,也为稻鱼共生产业的发展提供了基础。但是,一个区域的稻田是否适合发展稻鱼共生系统,常常受到当地自然和社会条件的影响,了解这些影响对有效推广稻鱼共生系统有重要意义。本文以我国南方10省为研究区域,从自然和社会经济因素两个方面分析了稻鱼共生系统的推广潜力。研究利用气象资料和农业统计数据,基于地理信息系统构建了研究区域内的稻田地理分布数据库,确定了15个影响稻鱼共生系统推广效率的指标,通过指标的层级模型和线性加权评分法对不同稻田的推广优先等级进行评估,并构建了基于稻田总面积、推广率和单产水平下鱼产量估算的简易模型。结果表明,综合自然和社会经济条件,研究区域内的稻田可划分为4个推广优先等级,面积占比分别为：等级1占29.6%（3.59×10⁶ hm²）,等级2占16.9%（2.05×10⁶ hm²）,等级3占24.2%（2.94×10⁶ hm²）和等级4占29.4%（3.57×10⁶ hm²）;其中湖南、四川、江西和浙江4省的稻田50%以上属于等级1和等级2,而在云南和贵州基本上所有的稻田都属于等级3和等级4。等级1和等级2的稻田适合推广集约型稻鱼共生模式,这两个等级的稻田每个生长季可产出最高鱼产量分别为3.77×10⁶ t和2.15×10⁶ t;而等级3的稻田适合进行粗放型和集约型模式相结合的推广方式,粗放型和集约型模式最高鱼产量分别为0.62×10⁶ t和3.09×10⁶ t。本研究主要结果为合理制定稻鱼共生系统推广策略提供借鉴,也可为国内外稻田水产养殖产业发展规划的制定提供参考。     

The <Emphasis Type="Italic">Rg1</Emphasis> allele as a valuable tool for genetic transformation of the tomato 'Micro-Tom' model system

Background  

The cultivar Micro-Tom (MT) is regarded as a model system for tomato genetics due to its short life cycle and miniature size. However, efforts to improve tomato genetic transformation have led to protocols dependent on the costly hormone zeatin, combined with an excessive number of steps.