河套灌区玉米低温冷害监测评估指标的研究

低温冷害指标的确立是冷害研究的重要环节.为了减轻和防御河套灌区玉米低温冷害,利用内蒙古河套灌区12个站点1981-2012年的气象、玉米产量资料,及3个站点玉米发育期资料,通过分析晚熟、中晚熟、中熟品种正常年份的热量需求和主要发育期平均出现日期及标准活动积温,基于相对活动积温距平计算方法及其与产量的关联性,建立了积温指数指标,以动态监测玉米延迟型冷害的发生发展.通过20a的回代检验冷害发生与减产的一致性为68.3％,2a的外推检验一致性为85.7％.该指标综合反映了生长季各阶段低温累积效应和高温补偿效益,农学和生物学意义明确,可以在低温冷害监测、评估业务中应用.     

海南龙血树DcbHLH1的克隆与表达分析

碱性螺旋-环-螺旋(basic/helix-loop-helix,bHLH)转录因子在真核生物的生长发育过程中起着重要的调控作用。在前期龙血树转录组测序结果基础上克隆了1个海南龙血树bHLH转录因子基因,命名为DcbHLH1。序列分析显示,DcbHLH1阅读框基因序列长1 080 bp,编码360个氨基酸,推测分子量为39 ku,等电点为8.21。氨基酸序列比对结果显示,DcbHLH1具有bHLH转录因子家族保守的HLH结构域。进化分析结果表明,DcbHLH1和中粒咖啡中的bHLH亲缘关系最近。定量PCR结果表明,DcbHLH1在诱导剂处理后3 d内表达量快速下降,到第6天达到最低,与转录组测序的数字表达谱一致。DcbHLH1在海南龙血树的根、茎、叶等组织中均有表达,但在叶中表达量较高,根中表达量最低。结果为进一步分析DcbHLH1在龙血树中的功能奠定了基础。     

Aphicidal Activity of an Ageraphorone Extract From Eupatorium adenophorum Against Pseudoregma bambucicola (Homoptera: Aphididae,Takahashi)

The bamboo aphid, Pseudoregma bambucicola, is an important insect pest of bamboo that affects normal bamboo growth and induces sooty molds. The control of P. bambucicola involves the application of chemicals, such as imidacloprid, to which many species are resistant. In this study, we isolate a novel botanical pesticide (9-oxo-10,11-dehydro-ageraphorone) from an Eupatorium adenophorum(Asteraceae: Compositae) petroleum ether extract and test the aphicidal activity of this compound against P. bambucicola in laboratory bioassay and field-based experiments. This ageraphorone compound at a concentration of 2 mg/ml caused 73.33% mortality (corrected mortality [Subtracted the mortality of the negative control]: 70%) of P. bambucicola by laboratory bioassay within 6 h. Even at lower concentrations, this compound caused greater 33% mortality (corrected mortality: 30%) of aphids. Field experiments with naturally infested bamboo plants showed that two applications of 2 mg/ml ageraphorone to infested plants completely cleared infestations within 30 d. These effects were similar to those of the positive control (imidacloprid). These results reveal that 9-oxo-10,11-dehydro-ageraphorone exhibits significant aphicidal activity against bamboo aphids. We suggest that future research be directed at developing this ageraphorone compound from E. adenophorum as an aphicidal agent for biocontrol.     

Structural Analysis and Anticoagulant Activities of the Novel Sulfated Fucan Possessing a Regular Well-Defined Repeating Unit from Sea Cucumber

Sulfated fucans, the complex polysaccharides, exhibit various biological activities. Herein, we purified two fucans from the sea cucumbers Holothuria edulis and Ludwigothurea grisea. Their structures were verified by means of HPGPC, FT-IR, GC–MS and NMR. As a result, a novel structural motif for this type of polymers is reported. The fucans have a unique structure composed of a central core of regular (1→2) and (1→3)-linked tetrasaccharide repeating units. Approximately 50% of the units from L. grisea (100% for H. edulis fucan) contain sides of oligosaccharides formed by nonsulfated fucose units linked to the O-4 position of the central core. Anticoagulant activity assays indicate that the sea cucumber fucans strongly inhibit human blood clotting through the intrinsic pathways of the coagulation cascade. Moreover, the mechanism of anticoagulant action of the fucans is selective inhibition of thrombin activity by heparin cofactor II. The distinctive tetrasaccharide repeating units contribute to the anticoagulant action. Additionally, unlike the fucans from marine alga, although the sea cucumber fucans have great molecular weights and affluent sulfates, they do not induce platelet aggregation. Overall, our results may be helpful in understanding the structure-function relationships of the well-defined polysaccharides from invertebrate as new types of safer anticoagulants.     

新时期农民增收的探索与思考

全面实现小康社会,农民的小康尤为重要。要实现农民的小康,实现增收致富,就必须为发展农业、提高农民收入提供良好的政策环境和社会环境。当前,农民持续增收仍然面临很多困难和压力。该文结合工作实际就新时期农民增收问题展开分析和讨论。      

不同产业沼气作物农田净生态系统生产力和水分利用效率比较

产业沼气作物是发酵制气的重要原料,开展产业沼气作物农田净生态系统生产力(net ecosystem production,NEP)和水分利用效率(water use efficiency,WUE)的研究,为产业沼气作物的筛选和种植提供依据。采用静态钠石灰吸收法和静态箱-红外CO2分析仪法、非称重式蒸渗仪法测定了常规种植条件下4种作物农田NEP和群体水分利用效率(population water use efficiency,WUEp)、生态水分利用效率(ecosystem water use efficiency,WUEe),并设裸地进行对照。结果表明:1)观测的5个处理,NEP的大小顺序是杂交狼尾草(17 533.1 kg/hm2)曲晨9号玉米(9 172.9 kg/hm2)云瑞88玉米(8 462.7 kg/hm2)紫花苜蓿(273.6 kg/hm2)裸地(-2 377.0 kg/hm2),4种作物农田是CO2的汇,裸地是源。2)WUEp大小排序为杂交狼尾草(10.89 kg/m3)曲晨9号(7.23 kg/m3)云瑞88玉米(6.79 kg/m3)紫花苜蓿(3.46 kg/m3)。WUEe大小顺序为杂交狼尾草(4.19 kg/m3)曲晨9号(2.38 kg/m3)云瑞88(2.20 kg/m3)紫花苜蓿(0.06 kg/m3),与NEP的排序相同。以生物量、NEP、WUEp、WUEe来衡量,杂交狼尾草优于其他3种作物,可优先推广种植。     

雪莲湾·蓝海新村居住区景观设计

从实际项目出发,对居住区景观设计的方法进行了探讨,通过雪莲湾.蓝海新村居住小区的创作实践,提出结合场地环境、塑造人性化景观的设计方法,阐述居住区景观空间结构中景观轴、核心片区、亲情绿地、防护绿带的设计要点,从点、线、面的角度对居住区整体形态设计进行了剖析。     

利用双重PCR技术检测柑橘溃疡病菌

建立了柑橘溃疡病菌的双重PCR检测方法.根据柑橘溃疡病菌的基因片段OPM-12SCAR fragment(AF312370),设计特异性PCR检测引物,并结合rpf基因设计的引物对柑橘溃疡病菌和其近缘菌株、植物原性细菌的DNA进行了双重PCR检测方法的研究.该方法特异性强,菌液浓度检测灵敏度达到102CFU/mL,能够满足快速、准确诊断柑橘溃疡病菌的要求.     

淀粉含量不同的两类小麦品种籽粒淀粉积累及关键酶活性的变化

为给新疆小麦品质育种提供理论依据,在新疆灌溉农业条件下,选用淀粉含量差异较大的普通小麦品种新春24、E28（高淀粉含量组）和宁春16、安农9912（低淀粉含量组）为材料,测定了籽粒灌浆过程中总淀粉及淀粉组分的含量,同时测定了籽粒束缚态淀粉合成酶（granule bound starch synthase,GBSS）、可溶性淀粉合成酶（soluble starch synthase,SSS）、淀粉分支酶（starch branching enzyme,SBE）和淀粉去分支酶（starch debranching enzyme,DBE）等相关酶的活性,并对其在籽粒灌浆过程中的变化及淀粉积累特征进行了相关分析。结果表明,高淀粉含量和低淀粉含量的小麦品种在籽粒淀粉积累量和积累速率上均存在明显的基因型差异。Logistic 方程拟合淀粉积累过程发现,支、直链淀粉最终积累量取决于积累启动时间的早晚和积累速率的大小,而最大积累速率出现时间的早晚对其调节作用较小。不同类型籽粒中的GBSS、SSS、SBE和DBE酶活性变化均呈现单峰曲线,峰值出现在花后12~24 d不等。4个品种的GBSS酶活性均与直链淀粉的积累速率呈极显著正相关,与总淀粉的积累速率达到显著或极显著正相关,但与支链淀粉积累速率的相关不显著。SBE和SSS酶活性与总淀粉的积累速率和支链淀粉的积累速率呈显著或极显著正相关,而与直链淀粉积累速率的相关不显著。DBE活性与淀粉积累速率的相关性不显著。淀粉合成关键酶活性间的相关性分析表明,高淀粉含量的品种DBE活性与SSS、GBSS和SBE相关达到显著或极显著水平,它们之间可能存在着协同作用。