干旱绿洲区枸杞林地面节肢动物功能群结构季节分布特征

为了解枸杞林地面节肢动物功能群结构季节分布特征,以宁夏绿洲枸杞林为研究对象,于2018年的春、夏、秋季节,采用陷阱诱捕法,调查了地面节肢动物功能群季节分布特征及其与环境因子之间的关系。结果显示:(1)枸杞林地面节肢动物功能群包括植食性、捕食性、腐食性和杂食性动物,个体数分别占6.31%、86.75%、2.01%和4.89%,其中以捕食性动物为主。(2)植食性地面节肢动物个体数和生物量表现为春季显著高于秋季,夏季居中;类群数表现为夏季显著高于秋季,春季居中。捕食性地面节肢动物生物量表现为夏季和秋季显著高于春季;个体数和类群数在不同季节间均无显著差异。腐食性地面节肢动物个体数、生物量和类群数在不同季节间均无显著差异。杂食性地面节肢动物个体数和类群数表现为春季显著高于夏季,秋季居中;生物量在不同季节间均无显著差异。(3)相关分析表明,捕食性地面节肢动物个体数与土壤含水量呈正相关关系,腐食性地面节肢动物个体数与土壤全磷呈正相关关系,杂食性地面节肢动物与土壤全氮呈正相关关系。但植食性地面节肢动物个体数则与土壤含水量呈负相关关系,杂食性地面节肢动物个体数与土壤温度和土壤全碳呈负相关关系。(4)pRDA分析表明,土壤含水量是影响地面节肢动物功能群结构季节分布的主要环境因子。结论:随着季节更替,宁夏干旱绿洲区枸杞林地面节肢动物的功能群组成差异较大,功能多样性差异较小。说明每个功能群的个体数和类群数对季节变化敏感,但功能多样性较稳定。     

Sucrose efflux and export from the maize scutellum*

Abstract During incubation of maize scutellum slices in fructose, there was an efflux of sucrose. Efflux was constant for at least 4 h at fructose concentrations of 70 or 100 mol m^?3. Efflux was increased by EDTA, and decreased by Ca²⁺. Efflux was independent of pH after EDTA treatment, but increased from untreated slices when the pH was lowered from 7 to 4. Uranyl ion and PCMBS (p-chloro-mercuribenzenesulfonic acid) abolished sucrose uptake, but were only weak inhibitors of sucrose efflux. These results are consistent with efflux occurring by simple diffusion through aqueous pores, but they do not rule out facilitated diffusion. Rates of sucrose export from the scutellum to the root shoot axis were estimated from measurements of axis respiration and dry weight gain. Sucrose efflux from scutellum slices was only 14-22% of the export rate. Sucrose efflux from the whole scutellum was only 3-4% of the export rate. It is concluded that the observed efflux is from leaky cells and does not represent sucrose on the way to the phloem along a path that includes the apoplast. These results support the idea that the path for sucrose from parenchyma cell to sieve tube in the maize scutellum is entirely symplastic.     

云南三种特色柑橘属果皮精油成分及活性研究

为探究云南特色柑橘属西双版纳曼赛龙柚、元江绿皮冰糖橙、德宏青柠的果皮精油成分及抗肿瘤活性。该研究采用水蒸气蒸馏法提取西双版纳曼赛龙柚、元江绿皮冰糖橙、德宏青柠果皮的精油,通过GC-MS开展定性定量成分分析,并通过MTT法开展果皮精油抑制肿瘤增殖研究。结果表明:德宏青柠果皮精油提取率最高、元江绿皮冰糖橙果皮精油次之、西双版纳曼赛龙柚果皮精油最低; 从西双版纳曼赛龙柚、元江绿皮冰糖橙、德宏青柠的果皮精油中分别鉴定出24种、11种、13种成分,月桂烯、萜品烯是三种精油的共有成分。西双版纳曼赛龙柚和元江绿皮冰糖橙的果皮精油中都含有β-蒎烯、3,7-二甲基-1,6辛二烯-3-醇、柠檬烯、α-松油醇,以及重要香料成分乙酸二甲基苄基原酯和二氢茉莉酮酸甲酯,其中西双版纳曼赛龙柚精油中柠檬烯含量高达72.097%,德宏青柠精油中含有活性成分柠檬醛。三种精油对胃癌细胞MKN-45、人乳腺癌细胞MCF-7和结直肠癌细胞HCT-116均有一定的抗肿瘤活性,并呈剂量依赖关系。该研究结果可为云南三种特色柑橘属植物的开发和应用提供科学依据。     

Prediction of heavy-metal concentrations in mature plants by chemical analysis of seedlings

Five plant species were cultivated on a soil from the Neckar alluvial fan near Heidelberg (FRG) polluted by the emissions of a cement plant. Thallium, cadmium and lead concentrations in seedlings and mature plants were determined by atomic absorption analysis. AdditionallyBrassica napus L.napus was grown on soils containing 5 different concentrations of heavy metals, achieved by mixing two similar soils, from the same area but with different metal concentrations. Thallium and cadmium were shown to be taken up by roots whilst lead which was also absorbed, was deposited mainly on the plant surface. However during cultivation in the winter months, a remarkable deposit of lead via the roots was found. Thallium in the soil from a anthrorogen source was more available to plants than thallium of geological origin. During the lifetime of a plant concentrations of thallium and cadmium were always highest in the seedling. The decrease in metal concentration with maturity depended on the plant species and the element, but was not a function of the metal concentration in the soil.     

调蓄河湖群菹草(Potamogeton crispus L.)功能性状特征及其与环境因子的关系

调水工程引起的多环境因子关联变化对沉水植物群落的影响机制有待深入探讨。以南水北调东线工程调蓄河湖群中菹草种群为研究对象,分析了京杭运河(YH)、高邮湖(GY)、洪泽湖(HZ)、骆马湖(LM)、南四湖上级湖(NS1)、南四湖下级湖(NS2)和东平湖(DP)7个调蓄河湖中菹草个体功能性状特征及其与环境因子间的关系。结果表明:(1)除高锰酸盐指数(COD_(Mn))、浊度(Tur)和底泥有机质含量(S_o)外,总氮(TN)、硝氮(NO_3-N)、氨氮(NH_4-N)、总磷(TP)、正磷酸盐(PO_4-P)、硅酸盐(SiO_4-Si)、叶绿素a(Chla)、总溶解性固体(TDS)、透明度(SD)、消光系数(K)、水温(T)、电导率(Cond)、酸碱度(pH)、溶解氧(DO)和底泥含水率(S_w)在河湖间差异达到了极显著水平;(2)菹草株高、茎分支数、茎节数、茎节长、茎直径、相对茎长、叶片数、叶厚、叶长、叶宽、叶面积、比叶面积、株重、茎重、叶重、茎叶比、茎干物质比、叶干物质比在河湖间差异极显著;(3)河湖群内菹草种群18个功能性状中,按变异系数从小到大依次为:叶宽、茎直径、叶长、茎干物质比、叶干物质比、叶面积、株高、茎节长、相对茎长、茎叶比、叶厚、茎节数、茎重、叶片数、株重、比叶面积、叶重、茎分支数;7个调蓄河湖间,按照所有性状变异系数平均值从大到小排序依次为:南四湖下级湖、洪泽湖和京杭运河、高邮湖、东平湖、南四湖上级湖、骆马湖;(4)环境因子共解释了功能性状方差变异的49.43%;叶性状主要受营养因子(TN、NO_3-N、SiO_4-Si)影响;茎性状与光照因子(Chla和SD)密切相关;底泥因子(S_o)对茎叶生物量分配起主要作用。     

Response of photosynthetic apparatus to moderate high temperature in contrasting wheat cultivars at different oxygen concentrations

The photosynthetic responses to moderately high temperatures (38 degrees C, imposed at 21% or 2% O(2) in air and 1500 mumol m(-2) s(-1)) were compared in wheat (Triticum aestivum L.) cultivars grown in northern regions of Ukraine and expected to be relatively sensitive to high temperatures ('North' cultivars) and in cultivars grown in southern regions and expected to be relatively heat-tolerant ('South' cultivars). Heating intact leaves in 21% O(2) for 1 h decreased CO(2) assimilation by c. 63% in 'North' cultivars and only c. 32% in 'South' cultivars, with a decrease in PSII activity being observed in only one of the 'North' cultivars. Carboxylation efficiency was decreased by about 2.7-fold in 'North' cultivars with no significant effect in 'South' cultivars. The maximum rates of carboxylation by Rubisco in vivo, V(cmax), estimated from Farquhar's model, increased more than 2-fold in 'South' cultivars and remained unchanged in 'North' cultivars while the maximum rate of RuBP regeneration, J(max), decreased by 53% and 21% in 'North' and 'South' cultivars, respectively. Where the heat treatment was imposed in 2% O(2) this increased (as compared with treatment at 21% O(2)) the inhibitory effect on CO(2) assimilation in tolerant cultivars, but decreased it in sensitive ones. The results suggested that differences in tolerance of moderately high temperatures in wheat relate to the stability of the Rubisco function and to RuBP regeneration activity rather than to the effects on PSII activity or stomatal control.     

洋葱花粉发育过程中ATP酶的分布特征(简报)

在真核细胞中,除了线粒体和叶绿体ATPase的功能是合成ATP外,其余部位ATPase是水解ATP以获取生物能量的代谢酶,在生物体细胞内广泛存在。探索ATPase在细胞中的分布状态是研究细胞生理状态的一种重要手段。ATPase在细胞中的多少可反映出细胞当时的生活状态,这一特征已被初步用于探索小麦和水稻雄性不育的细胞生物学研究中,希望通过比较可育花药和不育花药中ATPase的分布差异寻找雄性不育的机理,发现     

A multivariate diagnosis approach applied to celery

Celery (Apium graveolens L. var Dulce) is a high value crop affected at different growth stages by a variety of nutrient disorders. Each nutrient concentration can be corrected for its dependence on concentrations of other nutrients by recognizing plant composition as a closed system whose components add up to one. New variables z _i are computed as logratioed values of individual nutrients, where each nutrient concentration is corrected for the geometric mean of all nutrient concentrations. The z _i are used together with principal component analysis (PCA) to relate celery composition to yield, deficiency symptoms and quality parameters. A survey of commercial celery fields suggested that (1) celery growth is most often limited by P and N deficiencies associated with Fe toxicity; (2) K uptake is most likely to become limiting when the crop reaches 15 cm in height; (3) blackheart incidence can be traced to low levels of K and Mg in external petioles, and (4) cracked stem incidence is related to low B when the crop is 30 cm in height.     

外源-氧化氮供体硝普钠对黑麦草幼苗耐碱性的影响

采用营养液砂培方法,研究外源一氧化氮(NO)供体硝普钠(SNP)对NaHCO3胁迫下黑麦草幼苗生长、活性氧代谢和渗透溶质积累的影响.结果表明:60 μmol·L-1 SNP能够缓解100 mmol·L-1NaHCO3胁迫对黑麦草幼苗生长的抑制作用,减缓NaHCO3胁迫导致的叶片O2产生速率、H2O2和丙二醛(MDA)含量的增加,提高NaHCO3胁迫下幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)、质膜H+-ATP酶的活性和谷胱甘肽(GSH)、可溶性糖、可溶性蛋白质和脯氨酸的含量及K+/Na+比,降低过氧化氢酶(CAT)活性和抗坏血酸(AsA)含量,对游离氨基酸含量影响不大.上述结果表明,NO可能通过激活抗氧化系统活性、促进渗透溶质积累和改善Na+、K+平衡等缓解碱胁迫对幼苗的伤害,从而提高黑麦草的耐碱性.     

冠心病患者介入治疗前后血清IL-18、sCD40L和hs-CRP水平的变化及其意义

目的：探讨冠心病患者血清白介素18（Interleukin-18,IL-18）、白细胞分化抗原40配体（CD40L）、及高敏C反应蛋白（hs-CRP）水平在经皮冠状动脉介入术治疗前后的变化和意义。方法：选择经冠状动脉造影确诊的冠心病患者85例,根据病变程度分为单支病变组（n=32）、双支病变组（n=28）和多支病变组（n=25）,采用双抗体夹心ELISA法测定PCI术前术后血清IL-18、CD40L和hs-CRP水平。结果：血清IL-18水平测定结果：多支病变组高于双支病变组,双支病变组高于单支病变组;支架置入术后显著高于术前,差异均有统计学意义（P〈0.01）。血清CD40L水平测定结果：多支病变组高于双支病变组和单支病变组,差异均有统计学意义（P〈0.01）,双支病变组与单支病变组间差异无统计学意义（P〉0.05）;支架置入术后较术前显著升高,差异有统计学意义（P〈0.01）。血清hs-CRP水平测定结果：多支病变组高于双支病变组,双支病变组高于单支病变组;支架置入术后显著高于术前,差异均有统计学意义（P〈0.01）。结论：冠心病患者血清IL-18、CD40L和hs-CRP与冠脉病变程度密切相关,介入治疗可使冠心病患者血清IL-18、CD40L和hs-CRP水平升高,监测血清中IL-18、CD40L和hs-CRP水平变化可了解治疗效果和炎症程度。