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1.
通过采用营林卫生伐措施,清理遭受病虫危害的松树病枯死树、衰弱木、被压木、枯枝等,分析比较长年清理、集中清理和不清理等不同处理方式对松墨天牛成虫种群数量动态和松病枯死树数量变化情况。结果表明:经3年的处理,3种处理方式对松墨天牛成虫种群数量动态和松病枯死树数量变化差异明显。松墨天牛成虫虫口减退率和防治效果分别为:长年清理为94.09%和94.62%、集中清理为52.82%和57.03%,不清理(CK)天牛成虫虫口数量增加9.91%;松病枯死树减退率和防治效果分别为:长年清理为100%和100%、集中清理为69.28%和86.53%,不清理(CK)松病枯死树数量增加128.02%。  相似文献   

2.
为提高天敌昆虫寄生松褐天牛以此控制松材线虫病的效果,本研究采用松褐天牛疫木就地隔离,同时加上人工助放管氏肿腿蜂的方法,开展了控制松材线虫病的试验。结果表明:管氏肿腿蜂对松褐天牛低龄幼虫的致死率最高达68.50%,对中老龄幼虫的致死率为44.58%。3月和4月释放,松褐天牛死亡率分别为57.11%和65.64%,而5月份释放幼虫死亡率只有14.57%。将疫木劈为4开的情况下时,天牛死亡率最高,达71.33%。单边放蜂,松褐天牛的死亡率最高达67.18%。铁丝网、渔网和聚丙烯布隔离疫木对松材线虫病的发生都有较好的控制效果,其中铁丝网隔离后,健康松树死亡率下降到2.5%,渔网和聚丙烯布隔离后,松树死亡率为12%,均显著低于对照的80%。表明隔离松疫木加上施放管氏肿腿蜂能有效控制松材线虫病流行危害。  相似文献   

3.
花绒寄甲作为天牛类害虫的重要天敌在我国广泛应用于生物防治,尤其在控制松材线虫最重要的传播媒介松褐天牛方面发挥了重要作用,它在自然界与不同种类的天牛长期协同进化,形成了不同生物型。本文在辽宁省抚顺松材线虫病疫区的疫木上调查发现了花绒寄甲越冬成虫,通过形态学和生物学观察,确定了该花绒寄甲为云杉花墨天牛生物型花绒寄甲。这是花绒寄甲作为云杉花墨天牛的自然天敌在我国首次被发现,这将对中国北方地区松材线虫病传播媒介的防治起到积极的推动作用。  相似文献   

4.
Selected strains of non-pathogenic rhizobacteria have the ability to trigger an induced systemic resistance (ISR) response in plants. In Arabidopsis, rhizobacteria-mediated ISR has been extensively studied, using Pseudomonas fluorescens WCS417r as the inducing agent and P. syringae pv. tomato DC3000 (Pst) as the challenging pathogen. To investigate how far expression of ISR depends on the level of basal resistance, 10 different Arabidopsis ecotypes were screened for their potential to express WCS417r-mediated ISR and basal resistance against Pst. Two Arabidopsis ecotypes, RLD and Wassilewskija (Ws), were found to be blocked in their ability to express ISR. This ISR-noninducible phenotype correlated with a relatively low level of basal resistance against Pst. Genetic analysis of crosses between the ISR-inducible ecotypes Columbia (Col) and Landsberg erecta (Ler), on the one hand, and the non-inducible ecotypes RLD and Ws, on the other hand, revealed that ISR inducibility and basal resistance against Pst were inherited as monogenic dominant traits that are genetically linked. Neither ISR inducibility, nor basal resistance against Pst was complemented in the F1 progeny of a cross between RLD and Ws, indicating that both ecotypes are affected in the same locus. This locus, designated ISR1, was mapped between markers Ein3 and GL1 on chromosome III. Interestingly, ecotypes RLD and Ws also failed to express ISR against the oomycetous pathogen Peronospora parasitica, but they were not affected in their level of basal resistance against this pathogen. Thus, the ISR1 locus controls the expression of ISR against different pathogens but basal resistance only against Pst and not against P. parasitica. Like ecotypes RLD and Ws, ethylene-insensitive mutants showed the isr1 phenotype in that they were unable to express WCS417r-mediated ISR and show enhanced susceptibility to Pst infection. Analysis of ethylene responsiveness of RLD and Ws revealed that both ecotypes exhibit reduced sensitivity to ethylene. Therefore, it is proposed that the Arabidopsis ISR1 locus encodes a component of the ethylene-response pathway that plays an important role in ethylene-dependent resistance mechanisms.  相似文献   

5.
为明确细菌在松材线虫生态适应性中的作用,本研究选择与致病相关的松材线虫伴生细菌GD1、马尾松内生细菌GD2以及具有杀松材线虫活性的湿地松内生细菌NJSZ-13为试验对象,测定经这3株芽胞杆菌菌株3个浓度低温驯化10、15和20 d后,在冷冻条件下松材线虫强毒虫株AMA3、中毒虫株AA3和弱毒虫株YW4的存活率和繁殖量。结果表明:低温驯化15 d和20 d后3株菌株对不同毒力线虫的活力影响较驯化10 d后的更显著。在低温驯化15 d、-20℃冷冻处理1 h后,5×106CFU/mL浓度菌株GD1处理下,虫株AMA3、AA3和YW4的存活率分别为77.22%、83.68%和84.26%,与对照差异显著;5×105CFU/mL浓度菌株GD1处理下,虫株AMA3、AA3和YW4的存活率分别为75.76%、80.67%和81.50%,与对照差异显著。5×106CFU/mL和5×105CFU/mL浓度菌株GD2处理下,与GD1处理组结果相似,菌株NJSZ-13处理组则与菌株GD1和GD2的结果相反。低温驯化15...  相似文献   

6.
The Ya Li pear (Pyrus bretschneideri) trees were sprayed three times with 2.5 mM salicylic acid (SA) around 30, 60 and 90 days after full flowering. The fruit were harvested at commercial maturity (about 120 days after full flowering), inoculated with Penicillium expansum, and incubated at 20 °C, 95–100% RH. The results showed that resistance to the pathogen of the mature pear fruit was remarkably enhanced by the SA sprays. Disease incidence in the SA-treated fruit was 58.0% or 26.5%, and lesion diameter on SA-treated fruit was 58.4% or 29.0% lower than that in/on fruit without SA treatment (control) on day 12 or 17 after incubation, respectively. The SA spray applied to the trees around 30 days after full flowering notably enhanced accumulation of hydrogen peroxide in the young fruit. Meanwhile, activities of defense enzymes, including peroxidase, phenylalanine ammonia-lyase (PAL), chitinase or β-1,3-glucanase in the young fruit from SA-treated trees was 29.5%, 60.0%, 24.4% or 35.7% higher than that in the control fruit 4 days after the SA spraying. Furthermore, after harvest, activities of PAL, chitinase and β-1,3-glucanase were still significantly higher in the mature pear fruit from the trees sprayed three times with SA than those of the control fruit. Activities of the antioxidant enzymes including catalase and ascorbate peroxidase in the young fruit were significantly reduced by SA spraying. However, the activity of another antioxidant enzyme, glutathione reductase in the young fruit was significantly enhanced by SA spraying. These results suggest that enzymes exerting their functions in different ways may be coordinately regulated by SA in the pear fruit. Our study indicates that treatment of SA sprays on the trees may provide further protection against postharvest disease of Ya Li pear fruit in practice and could be used as an alternative and economical approach to reduce application of chemical fungicides.  相似文献   

7.
树栖真菌对扩散型松材线虫生活史的影响   总被引:1,自引:0,他引:1  
 松材线虫病是一种涉及多个生物因子的复杂病害系统,其病原松材线虫的生活史受媒介昆虫、寄主、树栖真菌和伴生细菌等多种因素影响。利用感染松材线虫病的马尾松林内的两种优势内栖真菌的3个菌株,松球壳孢(Sphaeropsis sapinea)E11、MHS7.3和小孢拟盘多毛孢(Pestalotiopsis microspora)M32,接种于松褐天牛模拟蛹室,研究松褐天牛蛹期和羽化过程松材线虫种群动态,以及松褐天牛携带扩散型松材线虫的动态变化。结果表明,天牛发育处于蛹期时,松材线虫主要以扩散型三龄幼虫(J)附着于天牛体表;发育至羽化期时,松材线虫主要以扩散型四龄幼虫(J)位于天牛体内。不同优势内栖真菌接种处理下,松褐天牛携带的扩散型幼虫数量的大小顺序为:小孢拟盘多毛孢M32>松球壳孢E11>松球壳孢MHS7.3,这与模拟蛹室中松材线虫种群的大小顺序是一致的,表明松褐天牛携带的线虫数目与蛹室中线虫种群的大小关系密切。在松褐天牛携带的J、J和扩散型幼虫(J+J)占线虫种群比例方面,松球壳孢E11和MHS7.3均大于小孢拟盘多毛孢M32,显示不适宜繁殖的真菌能促进群体内更多个体转化为扩散型虫态。J在蛹期的第二天即从天牛体内分离得到,但数量极少,随着J在羽化前达到最大值,J也开始大量出现,预示着较大J种群数量可能是J大量发生的基础条件之一。研究结果表明在松材线虫的扩散过程中,松林优势树栖真菌对媒介天牛携带的松材线虫数量产生显著影响。  相似文献   

8.
Findings from 2 years of field experiments investigating the relationship between Globodera rostochiensis and Rhizoctonia solani on unique field sites are reported. In 2000, a field experiment was positioned on land that had previously been used for experimental work investigating integrated potato cyst nematode (PCN) management methods. This study had produced an ‘untypical’ mosaic of PCN population densities ranging from 5 to 221 eggs g−1 soil. In 2001, the field experiment was conducted on a different field site and overlaid on a focus of G. rostochiensis population densities ranging from 11 to 108 eggs g−1 soil. In each experiment, potatoes (cv. Désirée) were grown in plots with similar population densities of G. rostochiensis that were either uninoculated or inoculated with R. solani. A series of potato plant harvests were undertaken to investigate the effects of nematode infestation on the incidence and severity of R. solani diseases and the associated development of plants. In both experiments, a clear relationship was found between the density of G. rostochiensis juveniles present in potato roots and the incidence of stolons infected by R. solani, 6 weeks after planting. For the first time this interaction has been determined under field conditions. The results of the study suggest that the interaction between nematode and fungus is indirect and possible mechanisms are discussed.  相似文献   

9.
The ability of selected strains of fluorescent Pseudomonas spp. to cause induced systemic resistance (ISR) in Eucalyptus urophylla against bacterial wilt caused by Ralstonia solanacearum was investigated. Four of the five strains used can produce salicylic acid (SA) in vitro and, therefore, chemical SA, that is known to induce resistance in many plant species, was used as a reference treatment. Whereas a soil drench with SA did induce systemic resistance in E. urophylla, infiltration of SA into leaves did not. None of the fluorescent Pseudomonas spp. strains caused ISR against bacterial wilt when applied to the soil, but two strains, P. putida WCS358r and P. fluorescens WCS374r triggered ISR when infiltrated into two lower leaves 3–7 days before challenge inoculation. A mutant of strain WCS358r defective in the biosynthesis of the fluorescent siderophore pseudobactin, did not cause ISR, while the purified siderophore of WCS358r did, suggesting that pseudobactin358 is the ISR determinant of WCS358. A siderophore-minus mutant of WCS374r induced the same level of disease resistance as its parental strain, but the purified siderophore induced resistance as well, indicating that both the siderophore and another, unknown, inducing determinant(s) of WCS374r can trigger ISR in Eucalyptus. A possible role of WCS374r-produced SA remains uncertain. Transformation of a siderophore-minus mutant of WCS358 with the SA biosynthetic gene cluster from WCS374 did not enable this transformant to cause ISR in E. urophylla.  相似文献   

10.
To study the relationship between resistance to pine wilt disease and the migration or proliferation of pine wood nematodes (PWN) (Bursaphelenchus xylophilus), we conducted experiments using clonally-propagated Japanese black pines (Pinus thunbergii) with pre-evaluated individual resistance levels. Bark including the cortical resin canals—one of the main migration pathways of PWN—was removed by girdling, but neither the migration of PWN nor symptom development of pine wilt disease were inhibited by this treatment in non-resistant clones. Histological observations showed no significant differences in the lumen area or the number of cortical- and xylem- axial resin canals between resistant and susceptible clone groups from a half-sib family. A bioassay using methanol extracts from resistant and susceptible clones showed that extracts from both clones showed similar attractant effects to PWN, but neither had repellent effects. The resistant clones were multi-inoculated with PWN into three split points to mimic migration in the stem. The proportion of damaged plants was not significantly different from that in single-inoculated plants (control). In this experiment, the number of PWN detected from partially-damaged plants was much higher than that from non-damaged plants. An inoculation test using stem cuttings showed that the population of PWN increased in susceptible cuttings at 1–20 days after inoculation (dai), while it remained unchanged or gradually decreased in resistant cuttings. These findings suggested that the factors contributing to resistance were associated with inhibiting the proliferation of PWN, rather than inhibiting their migration.  相似文献   

11.
PCR-RFLPs of ITS-rDNA and PCR with species-specific primers were developed for identification of cysts and juveniles of the beet cyst nematode Heterodera schachtii. Restrictions of PCR product by MvaI or ScrFI distinguish H. schachtii, H. betae, H. trifolii and H. medicaginis. RFLP profiles with eight restriction enzymes for these four nematode species are presented. Based on Internal Transcribed Spacer sequences of populations from several Schachtii group species, a specific primer for H. schachtii was designed, permitting amplification of the target sequence from juveniles and cysts of the beet cyst nematode. A duplex PCR protocol tested with a wide range of nematode samples is described.  相似文献   

12.
Fluorescent pseudomonads and nonpathogenic Fusarium oxysporum have been shown to suppress fusarium wilts. This suppression has been related to both microbial antagonism and induced resistance.The aim of the present study was to assess the relative importance of systemic induced resistance in the suppression of fusarium wilt of tomato in commercial-like conditions by a reference strain of each type of microorganism (P. fluorescens WCS417r and nonpathogenic F. oxysporum Fo47). The spatial separation of the pathogen and the biocontrol strains excluded any possible microbial antagonism and implicated the involvement of the systemic induced resistance; whereas the absence of any separation between these microorganisms allowed the expression of both mechanisms. Since systemic induced resistance has often been associated with the synthesis of PR-proteins, their accumulation in tomato plants inoculated with WCS417r or with Fo47 was determined.The analysis of the results indicates that the suppression of fusarium wilt by P. fluorescens WCS417r was ascribed to systemic induced resistance without any detection of the PR-proteins tested (PR-1 and chitinases). In contrast, the suppression achieved by nonpathogenic F. oxysporum Fo47 appeared to be mainly ascribed to microbial antagonism but also to a lesser extent to systemic induced resistance. This induced resistance could be related to the accumulation of PR-1 and chitinases.The possible relationship between the ability of Fo47 to suppress fusarium wilt more efficiently than WCS417r and its ability to show both mechanisms is discussed.  相似文献   

13.
An Israeli model forecasting leaf curl disease on peaches caused by Taphrina deformans was validated in the Emilia-Romagna region of northern Italy, during a three-year period (1996–1998), in 13 cases (year × location × cultivar). When the peach trees are susceptible to infection, the model uses mathematical functions to calculate the risk of infection on the basis of weather conditions (daily rainfall greater than 10mm, and maximum air temperature greater than 5°C), and it forecasts periods of possible symptom appearance based on the length of incubation. Peach trees became susceptible to infection between the end of January and mid March, when the first leaf buds attained phenological stage C, i.e. appearance of leaf apex. The trees remained susceptible for at least 9 weeks: the last infection occurred in mid-May.Since most of the leaf curl onsets observed in the orchards fell within the range of model forecasts, the model proved to be accurate in signalling both the first seasonal infection and repeated infections during the primary inoculum season. Few errors occurred, caused either by conditions of rainfall and temperature lower than the thresholds fixed in the model, or by discrepancies between forecast and actual length of incubation. Infection occurred also at 3.1–3.5°C, and with 9.6mm rainfall. Thus, thresholds should not be accepted too rigorously, and perhaps temperature should not be considered as a limiting factor for infection under the conditions of the present work. The length of incubation showed high variability: it was 23 days long on average, with a 95% confidence interval ranging from 20 to 27 days, and extreme values of 9 and 33 days.  相似文献   

14.
The ability of acibenzolar-S-methyl to induce resistance in pepper plants against Xanthomonas campestris pv. vesicatoria was investigated in both growth chamber and open field conditions. Growth chamber experiments showed that acibenzolar-S-methyl (300M) treatment protects pepper plants systemically and locally against X. campestris pv. vesicatoria. Evidence for this was a reduction in the number and diameter of bacterial spots and bacterial growth in planta. Systemic protection was also exerted by the acibenzolar-S-methyl acid derivative, CGA 210007, which may be produced by hydrolysis in the plant. The efficacy of acibenzolar-S-methyl was also found in open field conditions, where both leaves and fruit were protected from the disease. The highest efficacy (about 67%) was obtained by spraying the plants 6–7 times every 8–12 days with a mixture of acibenzolar-S-methyl and copper hydroxide (2.5 + 40ghl–1 active ingredient). Persistence and translocation data obtained from the growth chamber experiments revealed a persistence of acibenzolar-S-methyl lasting five days after treatment with rapid translocation and negligible levels of acid derivative formation. Since the protection exerted by acibenzolar-S-methyl against bacterial spot disease was observed when the inducer was completely degraded, it would appear to be due to SAR activation.  相似文献   

15.
为明确云杉花墨天牛Monochamus saltuarius的基因组功能信息,并筛选其生物防治相关基因,利用Illumina Novaseq 6000平台对云杉花墨天牛成虫进行转录组测序和生物信息学分析,并在NR、GO和KEGG数据库进行基因功能注释。结果显示,共获得190.06 Gb的云杉花墨天牛有效转录组数据,得到35 728个unigene,平均长度为1 270.83 bp,组装得到58 142个转录本,N50长度为2 135 bp。所得unigene在NR数据库中比对注释到相似基因数量占比最高的物种为光肩星天牛Anoplophora glabripennis,达到63.83%,在GO数据库中按功能注释分为生物学进程、细胞组分和分子功能3大类60个亚类,在KEGG数据库注释到44条代谢通路中。根据基因注释信息进一步挖掘出具有生物防治潜力的嗅觉相关基因43个、蜕皮相关基因149个、几丁质代谢相关基因35个、飞行相关基因6个和木质纤维素相关基因39个,可作为后期开发新的分子工具和云杉花墨天牛生物防治技术的备选靶标基因。  相似文献   

16.
This paper presents preliminary results on attempts to extract and characterize the volatile secondary metabolites contained in needles of differentPinus species and to ascertain the role played by these substances on the behavior ofThaumetopoea pityocampa (Denis et Schiffermüller) females, which show a marked preference, during the oviposition period, for some indigenous and exotic species of host plants existing in mixed formation. Limonene is the most abundant monoterpene extracted fromP. pinea needles, the least favored species of pine processionary caterpillar (PPC) females, although it is present in only very low amounts in otherPinus species. An increase was observed in limonene production byP. pinea at the start of the flight period of the PPC adult, and subsequently at the beginning of the females’ oviposition period. Assays carried out in two pine stands in central Italy showed that limonene, emulsified with water and sprayed on foliage of four different pine species plants,P. sylvestris, P. nigra, P. pinaster andP. radiata, during the PPC oviposition period, provided a satisfactory degree of protection. In fact, the number of egg clusters collected from treated plants was often lower than the number of egg clusters collected from control plants and was comparable to the number of egg clusters laid onP. pinea plants. In particular (R)-(+)-limonene, although not produced in nature by pines, was the most effective deterrent. However, the effect of (S)-(-)-limonene, the enantiomer biosynthesized by pines, was also adequate.  相似文献   

17.
Three conifer species (European larch, Norway spruce, Scots pine) were investigated for their resistance to five damping-off pathogens (Rhizoctonia solani, Fusarium solani, F. oxysporum, F. culmorum, F. avenaceum). Inoculation of the primary roots of seedlings with these pathogens caused host cell death which did not prevent the invasive growth of these fungi; seedlings that had formed secondary and tertiary roots could overcome the infection to a significant degree. Infections with R. solani caused significant mortality to all the conifer species. In contrast, the tree species expressed different levels of resistance when challenged with the Fusarium isolates, with Norway spruce being the most resistant compared to uninoculated controls. Some of the Fusarium isolates were more pathogenic to certain hosts than others; F. oxysporum for European larch, F. avenaceum for Scots pine, F. solani for European larch; only F. culmorum was significantly pathogenic to Norway spruce. No significant differences in disease severity were observed at different soil pH (4.3–7.5). Disease progression was delayed at lower (10–15°C) rather than higher temperatures (20–25°C).  相似文献   

18.
The operational Integrated Pest Management program for the southern pine beetle (SPB), Dendroctonus frontalis, currently consists of five components: prevention, prediction, detection, evaluation, and direct control. Full implementation of the program is hampered by economic, regulatory, and management constraints, and devastating SPB outbreaks still occur periodically. Recommendations for improving implementation include gaining public acceptance of the program, devising new management strategies, developing area-wide suppression techniques, coordinating efforts among landowners and government agencies, and revising the environmental analysis process. Severe outbreaks will continue without the creation of less susceptible forest conditions and more stable timber markets, plus the development of improved prediction, detection, communication, and suppression practices.  相似文献   

19.
Monochamus galloprovincialis Olivier (Coleoptera: Cerambycidae) is one of the vectors of the pinewood nematode Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle (Nematoda: Parasitaphelenchidae), the causal agent of pine wilt in susceptible pine trees. It is therefore important to study both the biological and ecological characteristics of the beetle. In this study reproductive potentials of female beetles reared on two pine species were investigated under laboratory conditions and compared using fertility tables constructed for beetles reared on each tree species. Beetle population parameters were compared between tree species. The intrinsic rate of increase and associated population parameters of beetles reared on Pinus sylvestris L. were consistently higher than those reared on P. nigra Arnold. This result suggests that P. sylvestris has a significantly greater positive effect on the reproductive potential of M. galloprovincialis populations than does P. nigra.  相似文献   

20.
Huanong AVM is a novel nematicide, which was synthesized from avermectin by selective oxidization of the hydroxyl group at C-4, followed by the reaction with glacial acetic acid. Effects of Huanong AVM on Bursaphelechus xylophilus are reported in this paper. Huanong AVM had strong nematicidal activity against B. xylophilus, with LC50 values of 14.84 μg/mL, 12.49 μg/mL and 11.05 μg/mL, respectively, at 48 h, 72 h and 96 h after treatment. The proteins that responded to Huanong AVM were identified by proteomic analysis. 2-DE analysis revealed eighteen differentially accumulated protein spots. Five spots were successfully identified by MS analysis, and three Huanong AVM induced proteins were annotated in the database as LEVamisole resistant family member (lev-11), ACTin family member (act-4) and Hypothetical protein Y52B11A.10. Two Huanong AVM-up-regulated proteins were assigned as PIP Kinase family member (ppk-3) and Hypothetical protein B0432.6. These proteins are involved in signal transduction, maintaining cytoskeletal structure and LEVamisole resistance. These results point to pathways that are important for the mode of the action of Huanong AVM on B. xylophilus.  相似文献   

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