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1.
为明确外源茉莉酸(JA)处理菜豆对美洲斑潜蝇抗性的诱导作用,采用生物测定和生化分析方法,研究了4种浓度JA喷施菜豆幼苗后,菜豆对美洲斑潜蝇的抗性及菜豆叶片过氧化物酶(POD)、多酚氧化酶(PPO)和脂氧合酶(LOX)活性的变化.结果表明,JA处理可以提高菜豆对美洲斑潜蝇的抗性及菜豆叶片3种防御酶的活性,且其抗性和防御酶活性提高程度均与JA浓度有关.0.1、1 mmol/L JA可显著降低美洲斑潜蝇成虫对菜豆的取食和产卵选择性,使卵或幼虫发育历期延长、幼虫取食量降低、蛹重减轻,而0.001和0.01 mmol/L JA仅对幼虫发育历期有显著影响.0.1 mmol/L JA处理后,菜豆叶片POD、PPO和LOX活性均显著升高,分别较对照增加33％、39％和80％,而0.001 mmol/L JA对菜豆叶片防御酶诱导作用不明显.  相似文献   

2.
为评估转cry1Ab/cry2Aj、cry1Ab/vip3DA玉米对棉铃虫Helicoverpa armigera(Hübner)、甜菜夜蛾Spodoptera exigua(Hübner)和斜纹夜蛾Prodenia litura(Fabricius)的抗虫性,在室内测定了3个转cry1Ab/cry2Aj玉米品系和1个转cry1Ab/vip3DA玉米品系对3种害虫幼虫存活和生长发育的影响,研究了该系列Bt玉米不同组织器官对害虫的杀虫活性和控制效果。结果显示,棉铃虫初孵幼虫取食各品系Bt玉米叶片96h后死亡率为87.50%~90.00%,取食花丝和雌穗的幼虫96h后几乎全部死亡;甜菜夜蛾初孵幼虫取食各品系Bt玉米叶片、花丝和雌穗168h后死亡率为22.50%~68.33%,幼虫的生长发育受到明显抑制,体重抑制率达85.00%~95.00%;斜纹夜蛾初孵幼虫取食各品系Bt玉米叶片、花丝和雌穗96 h后死亡率显著高于非转基因亲本对照,168h后幼虫死亡率达90.00%以上。研究表明,转cry1Ab/cry2Aj和cry1Ab/vip3DA玉米品系对棉铃虫和斜纹夜蛾的初孵幼虫表现出较好的抗性,可以作为转多基因抗虫玉米育种的备选材料。  相似文献   

3.
为研究棉铃虫成虫寄主偏好性和幼虫取食后生存表现之间的关系,明确两者在决定寄主过程中的作用,我们测定了交配后的棉铃虫雌成虫对16种植物(棉花、玉米、大豆、花生、番茄、辣椒、茄子、烟草、黄瓜、胡萝卜、西芹、杨树、月季、菠菜、包菜、大葱)的产卵偏好性和幼虫取食这些植物嫩叶后的存活和发育情况。棉铃虫雌成虫选择在烟草、茄子、棉花、胡萝卜、番茄、辣椒、玉米、西芹、大豆和花生等10种植物上产卵,但只有取食西芹、烟草、番茄、大豆、棉花和胡萝卜等6种植物叶片的初孵幼虫能够完成幼虫阶段的生长发育、化蛹并羽化,且取食植物嫩叶的幼虫的存活率、发育历期、蛹期和蛹重均差于取食人工饲料的幼虫。以上结果表明,棉铃虫雌成虫产卵寄主与其幼虫取食寄主之间存在并非一一对应的关系,幼虫的生存表现限定了棉铃虫的寄主范围。  相似文献   

4.
室内测定了转慈姑蛋白酶抑制素(API)基因棉对棉铃虫幼虫的抗虫活性及对中肠蛋白酶活性的影响。结果表明，以转基因棉饲养棉铃虫，对幼虫拒食率24h达76．49％，72h达80．57％，试虫体重在取食48h后显著下降，72h后较对照低54．04％。试虫取食转API基因棉后，中肠的强碱性胰蛋白酶和类胰凝乳蛋白酶活性显著降低，取食24、48h后的强碱性胰蛋白酶酶活性分别只有对照组的68．1l％和55．89％；类胰蛋白酶活性分别为对照组的85．87％和64．61％；对弱碱性类胰蛋白酶活性不明显。显示转API基因棉对棉铃虫幼虫中肠蛋白酶的抑制作用与对棉铃虫生长发育的阻滞有良好的相关性。  相似文献   

5.
为评估转Cry1Ac/1Ab基因棉花对棉铃虫Helicoverpa armigera的抗性及对非靶标害虫甜菜夜蛾Spodoptera exigua和斜纹夜蛾S.litura生长发育的影响,采用室内生测法测定其对棉铃虫的抗性及对甜菜夜蛾和斜纹夜蛾不同龄期幼虫存活率、营养代谢及中肠酶活性的影响。结果表明,转Cry1Ac/1Ab基因棉花对棉铃虫第2代幼虫的抗性程度最高,幼虫校正死亡率达91.33%,但对甜菜夜蛾和斜纹夜蛾的抗性程度较低,幼虫校正死亡率分别为15.33%和13.33%。甜菜夜蛾和斜纹夜蛾各龄期幼虫取食转Cry1Ac/1Ab基因棉花后,其存活率与取食常规棉花对照无显著差异;甜菜夜蛾对转Cry1Ac/1Ab基因棉花叶片的相对取食量、近似消化率分别为16.68和93.12%,均高于取食常规棉花对照的10.72和92.00%,但差异不显著,而斜纹夜蛾取食转Cry1Ac/1Ab基因棉花后的各项营养指标均低于取食常规棉花对照,差异也不显著。取食转Cry1Ac/1Ab基因棉花后,甜菜夜蛾的过氧化物酶活性为0.02 U/mg prot,显著低于取食常规棉花的0.05 U/mg prot;斜纹夜蛾的酸性磷酸酶活性为0.15 U/mg prot,高于取食常规棉花的0.10 U/mg prot,但差异不显著,其它中肠酶活性均低于对照,亦无显著差异。  相似文献   

6.
转Bt基因杨树对杨扇舟蛾的抗性   总被引：1，自引：0，他引：1  
通过室内饲养和组织切片,研究了表达Cry1A杀虫蛋白的中嘉8号杨树转Bt基因植株对杨扇舟蛾的抗虫效果。结果表明：随着饲养时间的延长,幼虫死亡率和体重抑制率呈上升趋势,处理2d仅分别为10%和6.85%,处理4d分别增加到48.33%和27.93%,处理10d分别达81.67%和63.03%。此外,处理12d取食非转基因杨树幼虫化蛹率100%,而取食转Bt基因杨树幼虫的化蛹率仅为18.18%。组织切片观察表明,取食转Bt基因杨树叶片幼虫的中肠上皮细胞排列松驰,与肠壁基底膜分离,细胞界限较模糊,部分上皮细胞形成空泡。因此,初步认为转Bt基因杨树对杨扇舟蛾幼虫的抗性表现为毒杀作用和抑制其生长发育。  相似文献   

7.
为阐明寄主植物番茄受害虫西花蓟马Frankliniella occidentalis取食、机械损伤及外源物质茉莉酸和水杨酸甲酯诱导后次生物质含量的变化,以及害虫如何通过调整体内解毒酶活性适应植物的防御反应,采用生化分析法测定了各诱导处理下次生物质黄酮、总酚和单宁含量及西花蓟马体内解毒酶多功能氧化酶(MFO)、乙酰胆碱酯酶(AchE)、谷胱甘肽S-转移酶(GSTs)和羧酸酯酶(CarE)活性的变化。结果表明:番茄叶片在各诱导处理下黄酮含量在36 h和48 h时均显著高于对照,相应时间段茉莉酸处理与水杨酸甲酯处理的黄酮含量升高最显著,分别达32.07 mg/g和31.76 mg/g;各诱导处理后24 h和36 h时,单宁和总酚含量均有不同程度下降,但总酚含量在48 h时显著升高,其中虫害处理增加最显著,达34.51 mg/g。取食各种诱导处理番茄植株6 h时,西花蓟马体内MFO活性均升高,AchE活性均受到抑制;取食除机械损伤外的其它诱导处理叶片6 h后,西花蓟马体内GSTs活性均被抑制,CarE活性均显著上升,其中取食水杨酸甲酯处理叶片的西花蓟马体内GSTs活性下降幅度最大,而CarE活性升高最显著,分别为3 882.35 U/mg和106.33 U/mg。表明各诱导处理不仅可以使番茄次生物质含量发生变化,诱导植株产生防御反应,也会使西花蓟马改变解毒酶的活性以适应寄主植物的诱导抗性,即寄主植物和害虫通过防御与反防御相互适应。  相似文献   

8.
转基因抗虫棉花对棉铃虫生长发育影响的系统评价   总被引：16，自引：1，他引：15  
以我国研制的转基因抗虫棉(Bt棉)品系CK595-1为材料,系统研究了对棉铃虫1～5龄幼虫存活及生长发育的影响。结果表明,Bt棉对棉铃虫的杀虫活性和体重抑制率有明显的器官和幼虫龄期间差异,其活性顺序为叶>蕾>铃>花,其作用随着幼虫龄期的增大而降低。棉铃虫1～4龄幼虫连续取食Bt棉叶片和棉蕾不能正常化蛹,5龄幼虫可部分化蛹及羽化;1～4龄幼虫取食Bt棉的花及2～5龄幼虫连续取食Bt棉铃后均可部分化蛹及羽化,化蛹率随龄期增大而增加。  相似文献   

9.
转Bt基因玉米对棉铃虫的抗性评价   总被引：2，自引：2，他引：2  
棉铃虫Helicoverpa armigem（Htlbner）是常年危害玉米的重要害虫。转Bt基因抗虫玉米为害虫的防治提供了新的途径。采用室内离体生物测定方法测定了孟山都转Bt基因抗虫玉米Yield—Gard不同组织对棉铃虫初孵幼虫的杀虫活性以及田间人工接虫抗性鉴定。Bt玉米花丝、苞叶和幼嫩雌穗对棉铃虫具有较高的杀虫活性，取食Bt玉米花丝和幼嫩雌穗（籽粒和穗轴）的棉铃虫初孵幼虫不能存活和完成幼虫期发育，而对照分别有51．0％和22．0％个体完成幼虫期发育。以Bt玉米雌穗苞叶饲养棉铃虫初孵幼虫，5天后幼虫全部死亡，而非Bt玉米对照仅为16．0％，差异显著。田间花丝期人工接种棉铃虫抗性鉴定试验结果表明，Bt玉米雌穗被害率为3．5％，危害级别为0．007，百株存活幼虫14．3头。而非Bt玉米雌穗被害率达到82．5％，危害级别为2．51，平均百株存活幼虫79．6头，显著高于Bt玉米。这些结果说明转Bt基因玉米穗期对棉铃虫的防治效果明理．  相似文献   

10.
丁布胁迫对亚洲玉米螟氧化还原系统的影响   总被引：1，自引：0，他引：1  
为探明丁布胁迫对亚洲玉米螟氧化还原系统的影响,采用酶活力测定方法和实时荧光定量PCR技术,研究了取食丁布含量差异显著的3个玉米品种登海662、浚单20和隆玉602叶片及模拟其叶片丁布含量的人工饲料后,玉米螟3龄幼虫氧化还原系统主要酶活性和谷氧还蛋白(Grx)mRNA转录表达的变化。结果显示:取食3个玉米品种叶片24 h后,亚洲玉米螟幼虫过氧化物酶和超氧化物歧化酶活性均显著高于对照,且在3个品种处理间差异显著,由大到小依次为登海662(118.30 U/mg和182.19 U/mg)、浚单20(107.13 U/mg和90.02 U/mg)和隆玉602(77.54 U/mg和93.59 U/mg)。取食浚单20可显著促进幼虫脂肪体Grx的表达,取食登海662可显著促进其中肠Grx的表达;取食模拟登海662叶片丁布含量的人工饲料12 h后,幼虫脂肪体中Grx表达量高于对应玉米叶片饲喂处理,而中肠部位则低于对应玉米叶片饲喂处理;取食模拟浚单20的结果与模拟登海662相反。表明亚洲玉米螟氧化还原系统在防御丁布胁迫过程中发挥着重要作用。  相似文献   

11.
Plant-mediated interactions (i.e., induced resistance) between plant pathogens and insect herbivores were investigated using several pests of the cultivated tomato,Lycopersicon esculentum. Single leaflets of tomato leaves were injured by allowing a third-instarHelicoverpa zealarva to feed on the leaflets or by inoculating the leaflets withPseudomonas syringaepv.tomato(the causal agent of bacterial speck in tomato;Pst) or withPhytophthora infestans(the causal agent of late blight). Leaflets on separate plants were sprayed with benzothiadiazole, a chemical inducer of resistance toPst. The effects of these treatments on the resistance of uninoculated or undamaged leaflets to bothPstandH. zeawere then assessed after appropriate periods of time. The levels or activities of several defense-related proteins were determined in parallel. Infection of leaflets byPstdecreased the suitability of uninoculated leaflets of the same leaf for bothH. zeaand forPst. Similarly, feeding byH. zeacaused leaf-systemic increases in resistance to bothH. zeaandPst. Infection of leaflets byP. infestans, in contrast, had no effect on resistance of leaflets toH. zea. Treatment of leaves with benzothiadiazole induced resistance toPstbut improved suitability of leaflets forH. zea. Feeding byH. zeacaused the systemic accumulation of proteinase inhibitor mRNA and the systemic induction of polyphenol oxidase activity; in contrast, treatment with benzothiadiazole and inoculation withP. infestanscaused the systemic accumulation of pathogenesis-related protein mRNA and the systemic induction of peroxidase activity. Inoculation of leaflets withPstcaused the leaf-systemic accumulation of both pathogenesis-related protein and proteinase inhibitor mRNA and the systemic induction of both peroxidase and polyphenol oxidase activity. These results provide clear evidence for reciprocal induced resistance involving certain pathogens and arthropod herbivores of tomato. In addition, these results provide several insights into the integration and coordination of the induced defenses of tomato against multiple pests and suggest that the expression of resistance against some pests may compromise resistance to others.  相似文献   

12.

The nematode species Meloidogyne incognita infects a large variety of cultivated crops and is one of nature’s most notorious pests. One cultivated plant which is prone to M. incognita infestation is the tomato. Knowing that in A. thaliana the PIN auxin efflux transporters distribution is being altered upon early invasion by M. incognita, the PIN1 allocation patterns in the giant cells of tomato plants after 15 and 25 days of infection were investigated. PIN1 was absent from the giant cells’ membrane in both assessment timings examined, indicating the maintenance of a local auxin maxima, which was also supported by IAA immunodetection. PIN1 distribution pattern could be attributed on either the nematodes nutritional needs throughout its life cycle or due to the tomato plants differential responses upon M. incognita infection.

  相似文献   

13.
Trap cropping is an environmentally friendly “alternative” pest management strategy. To maximize the efficiency of corn, Zea mays L. (Poaceae), as a trap crop for Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), we (i) tested the trap crop potential of corn varieties that are not a source of infestation, and (ii) determined the best corn planting time so as to concentrate H. zea in this trap crop and divert the pest from tomato, Solanum lycopersicum L. (Solanaceae). When corn silk emergence was synchronized with tomato flowering and fresh corn silk was present during the tomato flowering stage, H. zea infestation was lower in the tomato field with a corn border than in those without a corn border. Sugar Jean and Java corn varieties were good trap crops because few larvae persisted on the silks and their growth was low. These two varieties could reduce the risk of H. zea development and dispersion from corn borders.  相似文献   

14.
Twenty isolates of fluorescent pseudomonads were evaluated for their ability to control damping-off in tomato (Lycopersicon esculentum) and hot pepper (Capsicum annuum). These isolates were characterized as Pseudomonas fluorescens and Pseudomonas putida. Two isolates, PFATR and KKM 1 belonged to P. putida and the remaining 18 isolates belonged to P. fluorescens. Among these isolates, P. fluorescens isolate Pf1 showed the maximum inhibition of mycelial growth of Pythium aphanidermatum and increased plant growth promotion in tomato and hot pepper. P. fluorescens isolate Pf1 was effective in reducing the damping-off incidence in tomato and hot pepper in greenhouse and field conditions. Isolate Pf1 was further tested for its ability to induce production of defense-related enzymes and chemicals in plants. Earlier and increased activities of phenylalanine ammonia lyase (PAL), peroxidase (PO) and polyphenol oxidase (PPO) were observed in P. fluorescens Pf1 pretreated tomato and hot pepper plants challenged with Pythium aphanidermatum. Moreover, higher accumulation of phenolics was noticed in plants pretreated with P. fluorescens isolate Pf1 challenged with Pythium aphanidermatum. Thus, the present study shows that in addition to direct antagonism and plant growth-promotion, induction of defense-related enzymes involved in the phenyl propanoid pathway collectively contributed to enhance resistance against invasion of Pythium in tomato and hot pepper.  相似文献   

15.
为明确土壤中施用噻虫啉对番茄植株生长的影响,分别用36%噻虫啉水分散粒剂有效成分1.0、1.5、2.0、2.5、3.0和5.0 mg/株处理盆栽番茄植株,测定处理后30 d番茄幼苗的生长量、叶片保护酶活性及根系活力。结果表明:1.0~2.5 mg/株噻虫啉处理均可提高番茄幼苗展开叶片数、株高、主根长和鲜重等生理指标,3.0 mg/株处理与对照相比无显著差异,而5.0 mg/株处理则对番茄幼苗生长有显著的抑制作用。不同剂量的噻虫啉处理均可提高番茄幼苗叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、苯丙氨酸解氨酶(PAL)和多酚氧化酶(PPO)的活性及根系活力。PPO和SOD活性在2.0 mg/株噻虫啉处理时达到最大值,分别为47.9和14.2 U/(min·g FW),比对照高29.6%和49.5%;POD、CAT和PAL活性在2.5 mg/株剂量时达到最大值,分别为46.0、62.4和26.0 U/(min·g FW),比对照高47.0%、36.7%和35.3%。1.0~5.0 mg/株噻虫啉处理后番茄幼苗根系活力比对照提高2.7%~33.1%。研究表明,土壤施用适量的噻虫啉可显著促进番茄幼苗植株的生长。  相似文献   

16.
Twenty tomato (Solanum lycopersicon) cultivars were screened for resistance against bacterial spot disease incited byXanthomonas axonopodis pv.vesicatoria under field conditions with and without pathogen infection. Screening was done by artificially inoculating aX. axonopodis pv.vesicatoria suspension to 4-week-old tomato seedlings and observing them for typical symptoms of the disease. Seedlings were categorized into highly resistant, resistant, susceptible and highly susceptible cultivars on the basis of disease incidence. Tomato cultivars were screened for defense-related enzymes, total phenols and lignin contents. The temporal patterns of all these enzymes were estimated with a moderately susceptible tomato cultivar. Native PAGE analysis of both peroxidase (POX) and polyphenol oxidase (PPO) was carried out for the time course of enzyme activities and also by selecting three different tomato cultivars, following infection with the pathogen. Based on the inducible amounts of these enzymes upon pathogen infection, the tomato cultivars were correlated with the disease incidence under field conditions. A significant (P≤0.05) correlation was observed between the degree of host resistance and the enzyme levels. In highly resistant tomato cultivars the enzyme levels, total phenols and lignin contents were increased in comparison with highly susceptible tomato cultivars. Isoform analysis of POX and PPO enzymes indicated a clear difference between resistant and susceptible tomato cultivars in the number of isoforms and also in the intensity of each isoform in the presence of pathogen infection. The possible regulation of defense-related enzymes in imparting host resistance is discussed. http://www.phytoparasitica.org posting March 11, 2008.  相似文献   

17.
Several pathovars of Pseudomonas syringae produce the phytotoxin coronatine (COR)in vitro, and the availability of purified toxin has facilitated development of immunological detection methods. A modified, indirect competitive ELISA using the COR-specific monoclonal antibody 11B8 was developed to detect COR in various host plants infected by P. syringae. The estimated detection limit for COR was 50 pg per well, and COR could be reliably quantified from 5 to 40 ng ml−1. The subcellular localization of COR within infected tomato tissue was investigated using the COR-specific antibody MAb 8H3G2. Immunofluorescence microscopy and immunogold labelling showed that COR was present inside tomato cells and was associated with chloroplasts and particles of proteinase inhibitor I. Localization studies indicated that COR is mobile in infected plant tissue and can be detected in healthy tissue adjacent to the bacterial lesions.  相似文献   

18.
Corn (Zea mays) is widely cultivated for human food and animal feed and also provides an ecosystem service as a trap crop for the corn earworm Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) in tomato cropping systems. To be able to use corn as a trap crop for H. zea and to prevent it turning into a source of infestation, varieties are needed that are both attractive and resistant to H. zea. The main objective of this study was to compare the attractiveness to oviposition by H. zea and the resistance to H. zea of 10 sweet corn varieties in field conditions. We found Java, Garrison, Nova and Shinerock varieties that were both attractive to H. zea with a similar or higher number of eggs laid on silks than in the susceptible corn varieties, and resistant to H. zea, with fewer larvea per ear than in susceptible corn varieties. These varieties provide favorable habitats for generalist predators, ants, spiders, minute pirate bugs and lady beetles, which may account for their “dead-end” properties. Tropical farmers now have sweet corn varieties that can serve both as cash crops and as trap crops for H. zea.  相似文献   

19.
Abstract

The pine tree lappet moth Dendrolimus pini (Lasiocampidae) is one of the most dangerous pests of pine Pinus sylvestris stands in Central Europe. To develop biological control method of this pest, the bioassay was made to assess the sensitivity of D. pini caterpillars to native EPMs strains representing two species: Steinernema feltiae and Heterorhabditis megidis in laboratory conditions. The results showed higher activity of S. feltiae strains which parasitized 86.7 - 100% of D. pini caterpillars, compared to the 20-100% of insects parasitized by H. megidis strain. Most nematodes were found in caterpillars treated with S. feltiae (in average 40 IJs/caterpillar), the least – in individuals parasitized by H. megidis (in average IJs/caterpillar). No effect of dose and temperature on parasitizm was found with S. feltiae strains while in H. megidis increased doses resulted in higher extensity of parasitism. The results indicate higher biological activity of S. feltiae strains and advisability of their further studies in field experiments.  相似文献   

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