应用可拓学原理评价黄瓜根分泌物的化感潜势

 对黄瓜组培根分泌物的化感潜势进行可拓评价, 得出黄瓜组培根分泌物对菜豆幼苗生长有显著促进作用, 而对其它3种作物有明显的毒害作用, 毒害程度为黄瓜>甜瓜>番茄。同时, 建立了黄瓜组培根分泌液的化感效应的数学模型R_E = [ k₁R_p0 / ( k₂ - k₁ ) ] ( e^{- k1t} - e^{- k2t} ) ( e- ^k1a - e^{- k2a} ) , 说明了黄瓜组培根分泌液的化感效应与组培根培养时间( t) 以及根分泌液浓度( a) 显著相关。黄瓜根分泌物对4种受体作物显示出显著的化学干扰差异, 论证了植物种内(间) 发生的干扰作用与植物的品种(系) 有关, 从理论上得出菜豆可以作为黄瓜的间套作物或下茬作物。     

白菜耐光氧化能力鉴定及其与活性氧代谢关系的研究

 采用人工光氧化技术对30个常见白菜栽培品种进行光氧化处理, 以总叶绿素存留率作为评价指标, 利用系统聚类分析将供试品种划分为5个级别(1～5级) 。其中耐光氧化能力强的品种有青优4号、暑绿、抗热605、绿扬青、矮抗6号、华王; 不耐光氧化的品种有四倍体矮脚黄、绿星。在此基础上, 以耐光氧化品种抗热605与不耐光氧化品种绿星为材料, 研究了光氧化过程中活性氧代谢的特征。结果表明:在光氧化条件下, 白菜叶片内的抗氧化酶SOD、POD、CAT、APX活性受光氧化诱导升高, 但光氧化敏感性品种绿星的酶活性很快下降, 耐光氧化品种抗热605的酶活持续保持在较高的水平。因此, 绿星的O₂·生成速率、H₂O₂ 含量及MDA的积累量均高于抗热605, 最终导致品种绿星在光氧化下总叶绿素存留率低。表明抗热605植株内较高的抗氧化酶活性对提高耐光氧化能力起了重要作用。     

优质高产绿豇豆绿豇1号的选育与应用研究

绿豇1号是从宁波绿豇豆品种宁波绿带中经系统选育而育成的。其生育期48～61d,嫩荚绿色,长圆棍形,平均荚长58.1cm、宽0.72cm,单荚重18.6g,质地脆嫩,风味好,品质优,商品性佳。抗白粉病、煤霉病能力均较强。平均产量2000kg/667m2,较宁波绿带增产10%左右。绿豇1号已在浙江、上海、福建、江苏等省市示范推广应用。     

果实套袋对翠冠梨果锈形成的影响

翠冠梨[幸水×(杭青×新世纪)],具有成熟期早、丰产稳产、肉质松脆、汁多味甜等优良栽培经济性状,成为近年来在长江流域及其以南地区发展最为迅速的早熟梨品种之一。但其果面易生锈斑,对外观品质构成严重影响。翠冠梨果面锈斑的产生虽有其固有的遗传背景(为褐色与绿色皮色基因组成的杂合体控制的中间色),但实际产生与否、程度轻重还受栽培诸多因素综合影响,其中水湿条件最为关键。控制水湿条件以实行果实套袋最为有效。虽然梨果套袋研究报道甚多,但针对翠冠梨果锈产生特点展开的套袋技术研究报道却不多见。笔者在对翠冠梨锈斑发生规律与特点…     

Diurnal variations in gas exchange,chlorophyll fluorescence quenching and light allocation in soybean leaves: The cause for midday depression in CO2 assimilation

Gas exchange and chlorophyll fluorescence quenching analysis were carried out to investigate the diurnal variations in photosynthesis and light allocation in leaves of soybean. Leaf net CO₂ assimilation rate showed a bimodal diurnal pattern and midday depression of CO₂ assimilation was observed at 13:00 h. Depression in CO₂ assimilation at midday was mostly attributed to non-stomatal limitation since the reduction in net CO₂ assimilation rate was not followed by significant reductions in stomatal conductance and intracellular CO₂ concentration. Midday depression in CO₂ assimilation was found to be associated with reversible inactivation of photosystem II reaction centers and increases of antenna heat dissipation and photorespiration in response to the high light intensity. It is likely that PS II down-regulation, heat dissipation and photorespiration co-operated together to prevent the chloroplast from photodamage.     

Effects of mitochondrial ATP-sensitive potassium channel opener and hypoxic preconditioning on the hyperpolarization-activated current of sinoatrial node cells in neonatal rats

AIM: To compare the effects of hypoxic preconditioning (HP) and mitochondrial ATP-sensitive potassium (K_ATP) channel opener pretreatment on the hyperpolarization-activated current (I_f) in sinoatrial node cells.METHODS: Sinoatrial node cells were randomized to five groups: ① Control;②Hypoxia/reoxygenation (H/R);③ HP;④ Diazoxide (mitochondrial K_ATP channel opener)+H/R;⑤ 5-HD (mitochondrial K_ATP channel blocker)+HP.At the end of the experiment, I_f was recorded by whole-cell patch clamp technology.RESULTS: ①H/R significantly enhanced the current densities of I_f, shifted the current activation curve to more positive value by changing the half-activation voltage from (-98.9±2.4)mV to (-85.2±2.5) mV (P＜0.01).② Both diazoxide pretreatment and HP remarkably reduced the augmented current density caused by H/R and shifted the current activation curve to more negative value by changing the half-activation voltage to (-90.7±5.0) mV (P＜0.01) and (-92.2±1.9) mV (P＜0.01).③ 5-HD pretreatment blocked the effects of HP and reversed the half-activation voltage to (-86.3±2.7) mV (P＜0.01).CONCLUSION: The study demonstrates that both mitochondrial K_ATP channel opener pretreatment and HP make current density and kinetics of I_f to approach normal level and to maintain electrophysiological stability of sinoatrial node cells during H/R.     

林木害虫刺桐姬小蜂风险分析

刺桐姬小蜂（Quadrastichus erythrinael Kim）是我国大陆新发现的有害生物，根据刺桐姬小蜂的国内分布状况、潜在经济危害性、寄主植物的经济重要性、传播扩散的可能性和危险性管理难度等方面对其进行了风险分析，结果表明刺桐姬小蜂为我国风险中度偏高的有害生物。作者提出了检疫管理及除治措施。     

胭脂蚧的形态特征及蜡泌物超微结构的研究

采用制作玻片标本和扫描电镜技术研究了胭脂蚧Dactylopius confusus（Cockerell）在不同发育阶段的显微形态特征及蜡泌物的超微形态。结果发现：1龄若虫，它的五格腺分布全身，管腺有少量分布；背刺为柱状或截锥状，呈带状分布。雌成虫，它的管腺分布整个腹面，五格腺在腹面末端成簇，在背面单个或成群分布；背刺散布全身。蜡泌物的研究发现：若虫背腹面均分泌丝状蜡，断裂后形成C型小蜡圈；背刺实为中空管，具泌蜡功能。雄茧是由蜡丝交织构成。雄蛹表面附着白色蜡粉。而雌成虫蜡被是由粗蜡管及其周围的细长蜡丝组成。     

苇状羊茅与多年生黑麦草内生真菌菌丝基因组DNA提取的优化及PCR初步检测

感染内生真菌的禾草在牧草和草坪业上具有重要的生态和经济意义，家畜采食感染Neotyphodium coenophialum和N.lolii的苇状羊茅和多年生黑麦草会发生中毒。本研究收集天津口岸1998年以来进境的部分苇状羊茅和多年生黑麦草种子，对经镜检确认带有内生真菌的种子进行分离培养，对疑似菌株的菌丝用改进的Moiler等方法进行基因组DNA抽提，测定浓度及纯度，对照原方法，DNA的纯度有较大提高，浓度略有上升。Tubulin2基因的引物IS1-IS3扩增结果显示为单一的条带，结合形态学和序列比对，分离培养得到的菌株可以基本确定为N．coenophialum和N。lolii。根据Genbank中N.coenophialum和N.lolii的NC25基因序列设计出引物F1-R1，扩增得到能区分开N.coenophialum和N．lolii的单一条带（相差160bp），建立了N．coenophialum和N．lolii的PCR检测方法，结果准确可靠。     

杀虫植物非洲山毛豆的研究

非洲山毛豆原产于热带非洲,是一种优异的杀虫植物。本文对其生物活性、杀虫有效成分、作用机理、加工使用等方面进行了概述。