外源茉莉酸诱导枸杞对枸杞蚜生长发育和繁殖的影响

为了明确外源茉莉酸对枸杞的诱导抗性及其对害虫的影响,在室内25℃条件下用3种浓度的茉莉酸喷施枸杞苗木,以喷施丙酮+蒸馏水（配比1∶599）作为对照,测定了枸杞蚜在处理后苗木上的生长发育和繁殖情况。结果表明：外源茉莉酸诱导枸杞苗木后,枸杞蚜若虫发育历期延长,成虫寿命缩短、产仔量下降,枸杞蚜体重减轻,其影响程度与茉莉酸浓度有关。0.01 mmol/L茉莉酸诱导枸杞蚜若虫期最长,为4.93 d,比对照延长1.9 d。茉莉酸诱导成虫产仔量显著减少,且浓度越高产仔量越少,0.1 mmol/L浓度下产仔量为25头,比对照少19头。3种浓度的茉莉酸诱导均使枸杞蚜成虫寿命较对照缩短3 d左右。茉莉酸诱导对枸杞蚜体重的影响从3日龄后逐渐显现,5日龄时最显著,处理组与对照组蚜虫体重相差0.128～0.184 mg,对照组蚜虫平均重0.395 mg,0.01 mmol/L处理组蚜虫重量仅0.211 mg。     

外源激素和病原侵染对采后葡萄呼吸速率及组织内源激素的影响

葡萄采后施用外源ＡＢＡ可显著刺激其呼吸速率和乙释放率,ＡＢＡ对呼吸的促进作用大于Ｃ２Ｈ４;当葡萄被交链孢和灰霉葡萄孢侵染后,呼吸和乙释放均加强。交链孢侵染的葡萄呼吸速率在孢子形成后２ｄ达最大值,而灰霉区区孢侵染的葡萄呼吸速率在孢子形成即即达最大值。葡萄感病后,落粒现象加重,组织内源ＡＢＡ和Ｃ２Ｈ４含量增加,ＩＡＡＴ ＧＡ２含量减少。     

外源激素和病原侵染对采后葡萄呼吸速率及组织内源激素的影响

葡萄采后施用外源ABA可显著刺激其呼吸速率和乙烯释放率,ABA对呼吸的促进作用大于C2H4;当葡萄被交链孢和灰霉葡萄抱侵染后,呼吸和乙烯释放均加强。交链孢侵染的葡萄呼吸速率在孢子形成后2d达最大值,而灰霉葡萄孢侵染的葡萄呼吸速率在孢子形成时即达最大值。葡萄感病后,落粒现象加重,组织内源ABA和C2H4含量增加,IAA和GA3含量减少。     

外源茉莉酸及枸杞瘿螨危害诱导的枸杞防御反应

利用植物的诱导抗性防治病虫害越来越受重视, 为寻求枸杞害虫防治的新方法, 探索外源茉莉酸对枸杞的诱导反应及机制, 本研究测定了外源茉莉酸(jasmonic acid, JA)及枸杞瘿螨Aceria pallida Keifer危害对枸杞叶蛋白酶抑制剂(protease inhibitors, PIs)、 超氧化物歧化酶（superoxide dismutase, SOD）、 苯丙氨酸解氨酶（phenylalanine ammonia-lyase, PAL）活性及多糖（polysaccharide）、 木质素（xylogen）含量的变化。结果表明： 外源JA处理或枸杞瘿螨危害均使枸杞叶PIs, SOD和PAL活性及木质素含量显著提高, 却使多糖含量显著降低。胰凝乳蛋白酶抑制剂（chymotrypsin inhibitors, CI)和胰蛋白酶抑制剂(trypsin inhibitor, TI)在喷洒JA或枸杞瘿螨危害的第5 天增幅最大, 且在JA浓度、 瘿螨危害间差异显著(P<0.05), 其中, 0.1 mmol/L JA处理使CI增加了96%, TI增加了128%, 枸杞瘿螨危害使CI增加了94%, TI增加了122%。枸杞叶多糖含量在JA处理或瘿螨危害后显著降低(P<0.05), 且与JA浓度有关, 浓度越高, 降低越明显。 JA或瘿螨危害使枸杞叶木质素增加的最大值出现在处理后的第5 天, 高浓度JA、 瘿螨危害及低浓度JA分别使其增加了70%, 41%和36%, 三者之间差异显著(P<0.05), 第10 天增加幅度减低。 3种处理同样使SOD和PAL活性显著增加(P<0.05), 第5天时增幅最大, 高浓度JA 处理使枸杞叶SOD活性由对照的70.77 U增加到128.98 U, PAL活性由10.91 U增加到20.59 U, 第10天时呈现下降趋势。这些与抗性有关物质的变化及其变化趋势, 说明外源茉莉酸及枸杞瘿螨均可诱导枸杞产生防御反应, 而且反应的程度与茉莉酸浓度及处理后的时间有关。     

MeJA对大蒜鳞茎膨大及内源激素含量的影响

于大蒜鳞茎开始膨大时叶片喷施茉莉酸甲酯（Methyl Jasmonate,MeJA)可明显促进鳞茎膨大;酶联免疫法（ELISA）测定结果显示外源MeJA影响内源植物激素的含量,10μmol/LM可明显提高大蒜鳞茎膨大过程中IAA（吲哚乙酸）的含量。降低GA1 3（赤霉素）、ABA（脱落酸）的含量,但对iPAs含量的影响不大,分析表明MeJA可能通过与其他植物激素的协调作用而促进大蒜鳞茎膨大。     

宁夏枸杞果实生长发育期内源激素变化及关系研究

以‘宁杞1号’枸杞为材料,采用高效液相色谱技术,对不同发育时期宁夏枸杞果皮和种子内源激素(ZT、GA3、IAA、ABA)含量进行测定,以揭示其变化规律.结果显示:(1)种子中的生长素与果实横径和果实单粒重均呈极显著的正相关关系,与果实纵径呈显著正相关关系,即种子中的生长素在果实的增大中起着重要的作用.(2)果皮和种子中的赤霉酸含量都远远大于其他3种激素含量,且从第一次快速生长期(花后2～8 d)到缓慢生长期(花后8～25 d),其含量与种子中的生长素含量变化较为一致,进入第二次快速增长期(花后25～33 d)以后,果皮和种子中赤霉酸的含量则迅速下降,而种子中的生长素含量却急速上升,这可能是果皮和种子中的赤霉酸促进了种子内生长素的合成,而种子内的生长素可以直接调节果实细胞的伸长.研究表明,‘宁杞1号’种子中的内源激素在果实生长发育中起着重要的作用,且各激素间存在着平衡关系,果皮和种子中各种激素相互影响,共同促进果实的生长发育.     

高温调控对黄瓜霜霉病菌侵染的影响

采取温湿度相结合的方法来研究高温处理对黄瓜霜霉病菌（Pseudoperonospora cubensis Rostov)侵染的影响,比较研究了35－50℃4个温度梯度、50％－90％5个湿度组合处理对病菌致病性的影响。同一相对湿度条件下,随着温度的上升病菌致病性降低;40－50℃的高温范围内,在同一温度下随着湿度的不断升高,受处理病菌的致病能力逐渐下降。在RH80％以上、温度40℃以上时,病菌的致病力随着处理时间的延长而变弱;45℃以下的高温高湿处理病菌超过1h,病菌基本上没有致病性。通过高温控制苗期黄瓜霜霉病的研究,确定高温高湿防治苗期黄瓜霜霉病的最佳温湿度为45℃1h(RH80%)。通过高温致死菌诱导植株抗性的研究,初步明确高温处理致死的病菌可以短期诱导植株的抗性。     

低温胁迫下MeJA对小麦幼苗内源激素含量的影响

本文研究了茉莉酸甲酯（methyl jasmonate,MeJA）和低温处理对小麦幼苗生长和内源激素ABA和GA含量的影响。100μmol·L-1MeJA喷施叶面后,常温下能促进苗的生长,而低温下则抑制苗的生长,提高抗寒性。与此同时,两种培养温度下叶片中内源ABA含量比对照都显著提高,而GA含量在常温条件下显著提高,但在低温条件下则反而降低。MeJA处理促进了ABA/GA比值的提高,低温处理的促进作用更为显著。     

外源激素对马尾松花芽分化及内源物质的影响

为探讨马尾松球花形成与植物激素水平的关系,该研究对贵州省都匀无性系种子园11年生马尾松进行不同浓度的 IAA、IBA、GA3、BAP等植物激素处理,采用考马斯亮蓝G-250染色法、蒽酮法分别对不同浓度不同激素处理后的枝条上针叶中的可溶性蛋白质和可溶性糖含量变化进行测定,并在第二年开花时对试验枝条的开花情况进行了调查。结果表明：在8－11月份,进行500 mg·L-1的BAP 处理有利于马尾松雌球花和雄球花的形成,100 mg·L-1的GA3处理有利于马尾松雌球花的形成;而GA3250 mg·L-1和GA3500 mg·L-1处理有利于马尾松雄球花的形成,IAA 250 mg·L-1对马尾松雌雄球花同枝的数量有提高作用。在10－11月份,对马尾松进行500 mg·L-1的BAP、IAA、GA3处理后,马尾松针叶内蛋白质含量变化有显著影响;在10月份时,进行BAP 100 mg·L-1处理后,其可溶性糖含量及可溶性蛋白含量均可达到极显著水平。而在8月份与10月份时,分别进行IBA 100 mg·L-1与IBA 250 mg·L-1处理后,其可溶性蛋白含量与其对照差异处于极显著水平;在11月份时,进行GA3100 mg·L-1处理后,其可溶性蛋白含量与其对照差异处于极显著水平;而在11月份时,进行IBA 500 mg·L-1处理后,其可溶性蛋白含量与对照差异处于显著水平。     

植物生长调节剂对龙眼内源激素及花芽分化的影响

研究了ＰＰ３３３和ＧＡ对龙眼（ＤｉｍｏｃａｒｐｕｓｌｏｎｇａｎａＬｏｕｒ）,成花的作用及其与内源激素的关系。结果表明,ＰＰ３３３处理后,ｉＰＡ含量明显高于ＧＡ的处理,而ＧＡ含量则呈现由高到低逐渐下降的趋势,ＧＡ处理正好相反,ＰＰ３３３处理后芽中的ＡＢＡ含量明显低ＧＡ处理,表明高含量的ＧＡ和ＡＢＡ不利于花芽分化,而高含量的细胞分裂素则有利于花芽分化,外施Ｐ３３３可缩短花序长度,提高着果率和增加产量。     

Herbivore induced plant volatiles: Their role in plant defense for pest management

Plants respond to herbivory through different defensive mechanisms. The induction of volatile emission is one of the important and immediate response of plants to herbivory. Herbivore-induced plant volatiles (HIPVs) are involved in plant communication with natural enemies of the insect herbivores, neighboring plants, and different parts of the damaged plant. Release of a wide variety of HIPVs in response to herbivore damage and their role in plant-plant, plant-carnivore and intraplant communications represents a new facet of the complex interactions among different trophic levels. HIPVs are released from leaves, flowers, and fruits into the atmosphere or into the soil from roots in response to herbivore attack. Moreover, HIPVs act as feeding and/or oviposition deterrents to insect pests. HIPVs also mediate the interactions between the plants and the microorganisms. This review presents an overview of HIPVs emitted by plants, their role in plant defense against herbivores and their implications for pest management.     

植物抗虫“防御警备”: 概念、机理与应用

植物抗虫“防御警备”是指受到某些生物或者非生物因子刺激警备后,植物会提前做好抗虫防御准备,之后当再次受到害虫袭击时,植物会产生更加快速和强烈的抗虫防御反应,从而使自身抗虫性显著提高.这是近年来新发现的植物防御害虫的一种策略,是一种特殊的诱导抗虫机制.植食性昆虫的取食、分泌物、产卵、为害诱导的植物挥发物(HIPVs)以及某些有益微生物、植物营养元素、重金属和一些化学物质均可以引起植物产生抗虫防御警备.防御警备具有抗性高效、持久、环境友好,甚至可以遗传到子代等优点.本文综述了近年来有关植物抗虫防御警备的研究,主要概括了植物抗虫防御警备的一般特征、刺激警备因子和形成机制,并对其在生产实践中的应用前景进行了简要分析,提出了这一领域尚未解决的问题和亟待深入的研究方向.通过合适的方法使植物产生抗虫防御警备可以大大减少杀虫剂的使用,成为害虫综合防治的重要手段.     

An Induced Resistance Effect of Hydroxyurea on Plants Infected by Meloidogyne javanica

Aqueous solutions of hydroxyurea (HU) in various concentrations were applied as soil drenches to Meloidogyne javanica-infected plants. At a concentration of 15 ppm, the chemical hampered giant cell formation and the number of females on the roots was 20% of that of the control but the growth of the host plants was not affected. Additional HU applications after the one at infection did not add to the inhibitory effect. HU exerted its effect on M. javanica-infected tomato in five soil types. Soil temperature of 32 C neutralized the HU-induced resistance in much the same way that high temperature breaks the natural resistance in M. incognita-resistant tomato. This study provides further evidence of the role of HU as an induced resistance agent.     

A conserved pattern in plant‐mediated interactions between herbivores

Plant‐mediated interactions between herbivores are important determinants of community structure and plant performance in natural and agricultural systems. Current research suggests that the outcome of the interactions is determined by herbivore and plant identity, which may result in stochastic patterns that impede adaptive evolution and agricultural exploitation. However, few studies have systemically investigated specificity versus general patterns in a given plant system by varying the identity of all involved players. We investigated the influence of herbivore identity and plant genotype on the interaction between leaf‐chewing and root‐feeding herbivores in maize using a partial factorial design. We assessed the influence of leaf induction by oral secretions of six different chewing herbivores on the response of nine different maize genotypes and three different root feeders. Contrary to our expectations, we found a highly conserved pattern across all three dimensions of specificity: The majority of leaf herbivores elicited a negative behavioral response from the different root feeders in the large majority of tested plant genotypes. No facilitation was observed in any of the treatment combinations. However, the oral secretions of one leaf feeder and the responses of two maize genotypes did not elicit a response from a root‐feeding herbivore. Together, these results suggest that plant‐mediated interactions in the investigated system follow a general pattern, but that a degree of specificity is nevertheless present. Our study shows that within a given plant species, plant‐mediated interactions between herbivores of the same feeding guild can be stable. This stability opens up the possibility of adaptations by associated organisms and suggests that plant‐mediated interactions may contribute more strongly to evolutionary dynamics in terrestrial (agro)ecosystems than previously assumed.     

Induction of systemic acquired resistance in cotton by BTH has a negligible effect on phytophagous insects

Whether or not chemical changes in plants in response to pests (insects and pathogens) are general or specific remains unclear. Some evidence indicates that an induced response (IR) to arthropods via the octadecanoid pathway represents a distinct mechanism from the salicylic acid-based pathway of systemic acquired resistance (SAR) to pathogens. To further test this hypothesis, young cotton seedlings were activated with benzo (1,2,3) thiadiazole-7-carbothioic acid (S) methyl ester (BTH), an elicitor of SAR. The enzymatic activities of a number of pathogenesis-related (PR) proteins in young and old leaves of control and BTH treated plants were measured. BTH applications elicited marked increases in the activity levels of chitinase, peroxidase, and -1,3-glucanase both locally and systemically. The highest levels of induction were detected systemically in young leaves. Except for some local effects on whitefly oviposition, the induction of SAR by BTH had no effect on either host preference of whiteflies Bemisia tabaci (Gennadius) or on feeding efficiency of cotton bollworms Helicoverpa armigera (Hübner). We conclude that SAR induction via the salicylic acid pathway in Acala cotton has negligible effect on the tested insect herbivores.     

Proposed definitions related to induced disease resistance

A clear definition of induced disease resistance is lacking, even though the area has been extensively researched and described. The lack of a precise definition leads to potential confusion on whether an underlying mechanism for biological control is induced resistance. We propose definitions, which were developed at a NATO Advanced Research Workshop on biological control, for induced disease resistance and related terms. These definitions are intended to invoke debate and increase effective communication among investigators of induced resistance.     

环境条件对芽孢杆菌B-9987菌株防御酶诱导效应的影响

研究室内外条件下,海洋芽孢杆菌不同处理物对番茄防御酶系的诱导作用。分别使用不同浓度芽孢杆菌B-9987发酵液和无细胞滤液喷施番茄植株,于室内外两种环境条件下养殖,测定了处理11d内番茄5种防御酶的变化趋势。两种处理诱导抗性结果显示,在两种环境条件下处理植株苯丙氨酸解氨酶（PAL）、多酚氧化酶（ppo）、过氧化物酶（POD）、过氧化氢酶（CAT）较空白对照植株酶活性均有不同程度增加。除超氧化物歧化酶（SOD）外,室内环境较室外更利于B-9987菌株处理液对番茄防御酶系的诱导作用发挥;相同环境条件下,发酵液的处理诱导活性较强。B-9987菌株对番茄防御酶系有较好的诱导作用,但诱导作用的发挥受环境条件影响明显。