几种化学诱抗剂对甜瓜枯萎病的诱导抗性研究

以几种化合物作为诱抗剂,采用土壤处理和种子处理的方法对甜瓜枯萎病进行诱导抗性研究。结果表明,以0.1、0.5mmol/L水杨酸及4mmol/L草酸处理土壤的诱抗效果较好,相对防效分别达70.0%、51.3%和65.1%;以2mmol/L草酸、1mmol/L及0.5mmol/L水杨酸浸种处理的诱抗效果较好,相对防效分别达55.5%、48.9%及40.0%。     

植物免疫诱抗剂氨基寡糖素在广西的应用效果及前景分析

2011~2014年在广西番茄、葡萄、金橘等10种作物上开展植物免疫诱抗剂氨基寡糖素试验示范,结果表明:氨基寡糖素具有明显的促进作物生长、预防病害、提高品质及增加产量的效果。同时,分析和提出了广西应用植物免疫诱抗剂氨基寡糖素的前景和建议。     

壳寡糖对辣椒炭疽病和寒害的防治效果评价

对壳寡糖溶液处理后辣椒植株受寒害和炭疽病为害进行了评价。结果表明,经不同浓度壳寡糖溶液处理的辣椒植株,其寒害程度和炭疽病发病率明显低于用清水处理的辣椒植株,壳寡糖溶液处理能提高辣椒抗寒和抗炭疽病能力。其中,浓度为100 mg/L的壳寡糖溶液处理,对辣椒植株寒害和炭疽病控制效果最好,与25 mg/L和50 mg/L处理差异显著,但与浓度为200 mg/L的无显著性差异。     

灰茶尺蠖为害诱导茶树释放的互利素的鉴定

为鉴定灰茶尺蠖为害诱导茶树释放的互利素,遂以SDE法提取灰茶尺蠖为害茶梢和正常茶梢挥发物,经GC-MS检测,分别鉴定出31和25种组分,二者总含量相对于等剂量内标的含量分别是1863.8%和1124.6%。与正常茶梢相比,灰茶尺蠖为害茶梢挥发物中苯甲醛、反-2-癸烯醛、吲哚、水杨酸、反-2-己烯醛和己醛含量显著增加。将灰茶尺蠖为害茶梢挥发物的18种主要组分分别溶于液体石蜡制成10^-4g/mL味源,以Y形嗅觉仪检测茶尺蠖绒茧峰对味源的趋性;与液体石蜡相比,苯甲醛、水杨酸、反-2-己烯醛和己醛诱效显著,反-2癸烯醛、4-庚烯醛和吲哚的诱效明显,其他11组分无明显诱效。再将前7种组分配成10^-2g/mL引诱剂,分别载于橡皮头制成诱芯,附于芽绿粘板上,在茶园茶尺蠖绒茧蜂盛发期实施诱捕,携带前4种诱芯的芽绿粘板诱捕的蜂数明显多于后3种、且显著多于无诱芯的芽绿粘板,而且携带10^-2g/mL苯甲醛、水杨酸和反-2-己烯醛等量混合物诱芯的诱效最强。认为苯甲醛、水杨酸、反-2-己烯醛和己醛是灰茶尺蠖取食诱导的茶树互利素。     

不同药剂对茶饼病的田间防效评价

为筛选适用于防治茶饼病的药剂,以9种杀菌剂和2种植物诱抗剂作为供试药剂开展田间药效试验。结果表明：在第2次施药7 d后,各药剂处理的防效在61.07%～88.46%,均明显高于第1次施药7 d后的防效,其中,百菌清处理防效最高,可达88.46%,其次为矿物油、申嗪霉素、百里香油。2种植物诱抗剂壳寡糖和氨基寡糖素能显著提高多抗霉素与吡唑醚菌酯的药效。此外,茶饼病发生程度与温度有关,当气温升高到29℃以上时,病情指数急剧下降。     

内生细菌和几种诱抗剂对哈密瓜叶片防御酶系活性的影响

比较了内生细菌230、248、261菌株和诱抗剂水杨酸、壳聚糖中科2号、壳聚糖中科6号对哈密瓜细菌性叶斑病和疫霉病的诱导抗性作用及对哈密瓜叶片中防御酶系POD、PPO、PAL活性的影响。筛选出了具有诱导哈密瓜抗细菌性叶斑病和疫霉病菌复合侵染的内生细菌菌株，其中261菌株的诱抗效果可达78．2％，高于化学诱抗剂，且防病效果较持续稳定。施用水杨酸、壳聚糖中科2号、壳聚糖中科6号亦可诱导哈密瓜的抗病性，以壳聚糖中科2号最为显著，诱抗效果可达74．2％。结果表明：230、248、261菌株诱导接种和施用水杨酸、壳聚糖中科2号、壳聚糖中科6号处理哈密瓜幼苗，可显著提高叶片中PPO、POD和PAL的活性，并与哈密瓜植株抗病性增加呈正相关。     

0.61%二化螟性诱剂挥散芯对水稻二化螟的田间防效

【目的】明确0.61%二化螟性诱剂挥散芯对水稻二化螟的防治效果。【方法】设置不同诱芯投放密度和不同诱芯悬挂高度开展水稻二化螟诱集监测试验。【结果】在悬挂密度15～45枚诱芯/hm²、悬挂高度1.2m条件下,总诱虫量为238.50～548.50只/hm²,水稻枯心率为1.76%～0.96%,防治效果达69.54%～83.22%,其中45枚诱芯/hm²处理极显著高于15枚诱芯/hm²处理,与30枚诱芯/hm²处理和对照药剂0.61%二化螟性诱剂挥散芯30枚诱芯/hm²处理、200 g/L氯虫苯甲酰胺悬浮剂150 mL/hm²处理差异不显著。【结论】诱芯悬挂高度对二化螟雄蛾的诱捕效果有一定影响,其悬挂高度在1.2～1.4 m的诱蛾量最高。0.61%二化螟性诱剂挥散芯防治二化螟的推荐使用剂量30～45枚诱芯/hm²,诱芯悬挂高度以1.2 m左右为宜。     

0.136%赤·吲乙·芸苔可湿性粉剂等5种植物生长调节诱抗剂在香葱上的应用效果

为了明确0.136%赤·吲乙·芸苔可湿性粉剂等5种植物生长调节诱抗剂在香葱上的应用效果,开展不同处理对香葱生长及产量影响,筛选出适合在香葱上使用的植物生长调节诱抗剂,结果表明,0.136%赤·吲乙·芸苔可湿性粉剂和5%氨基寡糖素水剂连续使用3次后,香葱葱管数、分蘖数和株高、产量均有大幅度增加,可推荐在生产上使用。     

植物诱抗剂与拮抗菌剂联用对烟草生长及青枯病的影响

为探究植物诱抗剂与拮抗菌剂联用对烟草生长及青枯病的影响,采用多粘类芽孢杆菌、水杨酸和2,6-二氯异烟酸单独和联用处理进行田间小区试验,并设置空白对照,通过分析烟株农艺性状、青枯病发病情况和产量产值,系统评价了植物诱抗剂与拮抗菌剂联用的效果.结果表明,多粘类芽孢杆菌与水杨酸或2,6-二氯异烟酸联用均能有效促进烟株的生长;多粘类芽孢杆菌与2,6-二氯异烟酸联用对青枯病的防控效果显著高于其他处理;在单叶均质量和产量产值上,多粘类芽孢杆菌与2,6-二氯异烟酸联用处理效果最好.本研究为烟草青枯病的生物防治提供了新的方法和思路.     

化学合成寡糖诱导烟草抗黑胫病的初步研究

 抑菌测定和盆栽试验表明:化学合成的Lewis^x和Lewis^a寡糖对烟草黑胫病病原菌菌丝生长无明显影响;Lewis^x五糖和七糖处理烟草,可使烟草植株产生对黑胫病菌(Phytophthora nicotianae)的抗性,在处理浓度0~10μg/m L内,随着浓度增高诱导效果增强,当浓度达10 μg/m L时,诱导防病效果达90%以上。Lewisx七糖处理,可导致烟草叶片过氧化物酶(POD)、多酚氧化酶(PPO)和苯丙氨酸裂解酶(PAL)等防卫酶活性不同程度地提高,PPO、POD及PAL分别在处理后第4d、第6d和第8d达到最大值,比对照分别增加了70.7%、150.0%和142.8%。     

菌株NDBJJ-BFG的鉴定及其对马铃薯甲虫不同虫态的毒力测定

为筛选出对马铃薯甲虫Leptinotarsa decemlineata(Say)具有防治潜力的菌株,本研究从马铃薯甲虫僵虫虫体上分离菌株NDBJJ-BFG,通过形态学特征和分子生物学方法明确其分类地位,采用喷雾法和覆土法测定了不同浓度下该菌株对马铃薯甲虫室内毒力的致死中浓度LC50及半致死时间LT50。结果表明,经形态特征与r DNA ITS序列分析最终确定菌株NDBJJ-BFG为球孢白僵菌Beauveria bassiana(Bals.)Vuill。该菌株对1、2、3和4龄马铃薯甲虫幼虫的LC50分别为0.91×10~6、1.51×10~6、5.09×10~6和6.84×10~6个/m L;采用喷雾法和覆土法处理蛹的LC50分别为1.43×10~7个/m L和8.15×10~6个/m L,成虫的LC50分别为5.08×10~7个/m L和2.97×10~7个/m L。在孢子悬浮液浓度相同时LT50随虫龄的增大而延长,其中成虫的LT50最长,其次是蛹;在相同龄期下LT50随着孢子悬浮液浓度的增大而缩短。表明菌株NDBJJ-BFG对马铃薯甲虫1龄和2龄幼虫具有高毒力,其在马铃薯甲虫的生物防治中将具有较大的应用潜力。     

草甘膦铵盐在苎麻田的残留及消解动态

建立了简单、灵敏的土壤及苎麻中草甘膦残留量的气相色谱检测方法。土壤样品用0.01 mol/L 的氢氧化钠水溶液提取,其他样品用水和丙酮提取,经阴离子交换柱(AG1-X8)净化,与原乙酸三甲酯(TMOA)和冰醋酸反应,用气相色谱带火焰光度检测器(FPD)检测,外标法定量。结果表明:当草甘膦在麻蔸和土壤中的添加水平在0.05~1 mg/kg时,添加回收率分别为 73.6%~102.6% 和85.9% ~105.1%,相对标准偏差分别为2.3% ~8.1% 和5.4% ~13.0%。草甘膦的最小检出量(LOD)为0.5×10-10 g,在麻蔸中的最低检测浓度(LOQ)为0.05 mg/kg。2年3地的残留试验结果表明:草甘膦铵盐在湖南省、广西壮族自治区及福建省土壤中的半衰期分别为1.6~2.6 d,1.0~1.8 d和1.1~1.5 d。无论是在高浓度处理区 还是在低浓度处理区 ,苎麻收获时(距施药60 d),土壤和麻蔸样品中均未检出草甘膦铵盐。     

玫烟色虫草和球孢白僵菌对朱砂叶螨和二斑叶螨的致病力评价

为探寻具有杀螨潜力的生防真菌,采用喷雾法测定分析玫烟色虫草Cordyceps fumosorosea IF-1106菌株和球孢白僵菌Beauveria bassiana BB-1339菌株对朱砂叶螨Tetranychus cinnabarinus和二斑叶螨Tetranychus urticae卵、幼螨及雌成螨的致病力。结果表明,感染玫烟色虫草IF-1106菌株和球孢白僵菌BB-1339菌株后螨类的形态特征不一致,感染IF-1106菌株后形成棉絮状菌丝,而感染BB-1339菌株后则形成羊毛状菌丝。IF-1106菌株和BB-1339菌株对朱砂叶螨和二斑叶螨卵的LC₅₀分别为2.38×10⁷、8.26×10⁷CFU/mL和4.48×10⁷、1.21×10⁸CFU/mL,对朱砂叶螨和二斑叶螨幼螨的LC₅₀分别1.97×10⁷、8.26×10⁷CFU/mL和7.65×10⁶、8.99×10^5...     

利用表型芯片技术筛选利于枯草芽胞杆菌Bacillus subtilis BAB-1生长与芽胞形成的营养物质

为获得枯草芽胞杆菌Bacillus subtilis BAB-1菌株的芽胞高效率生产技术,采用Biolog微生物细胞表型芯片(phenotype microarray,PM)技术分析了适合该菌株细胞生长的营养物质、渗透压和pH等生长环境条件;通过单因素试验分析了5种碳源及5种氮源对该菌株生长及芽胞形成的影响。结果表明,BAB-1菌株能够利用114种碳源、228种氮源、29种磷源及29种硫源作为其营养物质,其中52种碳源、66种氮源、3种硫源及1种磷源能够明显促进该菌株的细胞生长;BAB-1菌株对渗透压的忍受能力较强,在1%～10%氯化钠、3%～6%氯化钾、2%～5%硫酸钠、5%～20%乙二醇、1%～6%甲酸钠、2%～7%尿素、1%～12%乳酸钠、20～200 mmol/L磷酸钠、10～100 mmol/L硝酸钠、10～100 mmol/L硫酸铵中均能较好的生长;BAB-1菌株对pH的耐受范围较广,在4.5≤pH≤10.0条件下均能够生长。葡萄糖与氯化铵分别是最适宜BAB-1菌株生长的碳源与氮源,在不同培养时间其菌体总量均最高,48 h时该菌株的菌体总量分别达到6.90×10~8CFU/mL与6.87×10~8CFU/mL;培养12 h时,D-木糖、D-核糖、L-阿拉伯糖及熊果苷能够显著提高BAB-1菌株的芽胞形成率,其中L-阿拉伯糖与熊果苷的芽胞形成率较高,分别为61.94%与66.92%;培养12～36 h,L-脯氨酸、L-谷氨酰胺及L-天冬酰胺能够显著提高BAB-1菌株的芽胞形成率,芽胞形成率介于27.88%～82.37%之间。表明表型芯片技术可以应用于枯草芽胞杆菌生长及芽胞形成营养物质的高通量分析及培养工艺的优化中。     

埃及吹绵蚧昆虫病原真菌的筛选、鉴定及其致病性测定

为明确埃及吹绵蚧Icerya aegyptiaca昆虫病原真菌在生物防治中的应用潜力,采用生物测定法筛选得到产孢量高和致病力强的优势分离株,根据形态学特征和rDNA ITS序列分析对优势分离株进行鉴定,并对其室内毒力和温室防效进行测定。结果显示,筛选得到的优势分离株为IJID003,产孢量最高,可达8.51×10~6个/mL,且致病力最强,处理埃及吹绵蚧2龄若虫5 d后,其校正死亡率为95.40%;根据形态学特征和r DNA ITS序列分析鉴定结果,确定该分离株为爪哇棒束孢Isaria javan‐ica。随着分离株IJID003接种浓度的增加,埃及吹绵蚧2龄若虫、3龄若虫和雌成虫的校正死亡率也随之增加,致死中时间LT50则递减;在分生孢子浓度为1.00×10~8个/mL时,其对2龄若虫、3龄若虫和雌成虫的LT50最小,分别为1.89、2.29、2.31 d;随着接种后天数的延长,致死中浓度LC50减小,在接种后6 d,其对2龄若虫、3龄若虫和雌成虫的LC50最小,分别为1.25×10~3、2.04×10~4、8.37×10~5个/mL,表明分离株IJID003对埃及吹绵蚧2龄若虫的毒力较其它2种虫态高;啶虫·毒死蜱2 000倍液对埃及吹绵蚧2龄若虫的前期致死速率较快,而分离株IJID003在后期侵染速率较快,处理后6 d两者的防效无显著差异,效果相当。表明爪哇棒束孢分离株IJID003具有产孢量高且致病力强的特点,在埃及吹绵蚧生物防治中具有较好的应用前景。     

Induction of systemic resistance to<Emphasis Type="Italic">Colletotrichum lindemuthianum</Emphasis> in bean by a benzothiadiazole derivative and rhizobacteria

Plants have developed mechanisms to resist secondary infection upon inoculation with a necrotizing pathogen, chemical treatment as well as treatment with some non-pathogenic microorganisms such as rhizosphere bacteria. This phenomenon has been variously described as induced systemic resistance (ISR) or systemic acquired resistance. In the present study, the chemical benzo(1,2,3)thiadiazole-7-carbothioic acid-S-methyl ester (BTH, acibenzolar-S-methyl), and the rhizobacteriaPseudomonas aeruginosa KMPCH andP. fluorescens WCS417 were tested for their ability to induce resistance toColletotrichum lindemuthianum in susceptible and moderately resistant bean plants (Phaseolus vulgaris L.). BTH induced local and systemic resistance when bean leaves were immersed in 10⁻³ to 10⁻⁷ M BTH 3 days before the challenge inoculation. At a high concentration (10⁻³ M), BTH induced resistance of the same order as resistance induced by the pathogenC. lindemuthianum, although at this high concentration BTH appeared to be phytotoxic. Soil and seed treatment with 1 mg kg⁻¹ BTH protected beans against anthracnose. BTH-mediated induced resistance was effective in susceptible and moderately resistant plants.P. aeruginosa KMPCH induced resistance in bean againstC. lindemuthianum only in a moderately resistant interaction. KMPCH-567, a salicylic acid mutant of KMPCH, failed to induce resistance, indicating that salicylic acid is important for KMPCH to induce resistance in the bean—C. lindemuthianum system.P.fluorescens WCS417 could induce resistance toC. lindemuthianum in a susceptible and in moderately resistant interactions. http://www.phytoparasitica.org posting Jan. 16, 2002.     

Assessment of <Emphasis Type="Italic">Pichia anomala</Emphasis> (strain K) efficacy against blue mould of apples when applied pre- or post-harvest under laboratory conditions and in orchard trials

The yeast Pichia anomala strain K was selected in Belgium from the apple surface for its antagonistic activity against post-harvest diseases of apples. The efficacy of this strain against P. expansum was evaluated in the laboratory in three scenarios designed to mimic practical conditions, with different periods of incubation between biological treatment, wounding of fruit surface, and pathogen inoculation. Higher protection levels and higher final yeast densities were obtained when the applied initial concentration was 1 × 10⁸ cfu ml⁻¹ than when it was only 1 × 10⁵ cfu ml⁻¹. The protection level correlated positively with the yeast density determined in wounds and was influenced by apple surface wetness. In orchard trials spanning two successive years, biological treatment against P. expansum, based on a powder of P. anomala strain K (1 × 10⁷ cfu ml⁻¹), β-1,3-glucans (YGT 2 g l⁻¹), and CaCl₂.2H₂0 (20 g l⁻¹), was applied to apples pre- or post-harvest under practical conditions and its effect compared with standard chemical treatments. The first year, the highest reduction (95.2%) against blue decay was obtained by means of four successive fungicide treatments and the next-highest level (87.6%) with pre-harvest high-volume spraying of the three-component mixture 12 days before harvest. The second year, the best results were obtained with post-harvest Sumico (carbendazim 25% and diethofencarb 25%) treatment and post-harvest biological treatment, both by dipping the apples, 88.3 and 56.3% respectively. A density threshold of 1 × 10⁴ cfu cm⁻² of strain K on the apple surface seemed to be required just after harvest for high protective activity, whatever the method and time of application. In the case of pre-harvest biological treatments, variations in meteorological conditions between the 2 years may have considerably affected strain K population density and its efficacies.     

柑橘衰退病毒含量对其蚜传效率的影响

为明确毒源植株和蚜虫中柑橘衰退病毒(Citrus tristeza virus,CTV)的发生情况与蚜虫传播CTV能力的关系,将褐色橘蚜、棉蚜、橘二叉蚜和绣线菊蚜置于分别感染了4个CTV分离株的锦橙上取食24 h后,运用巢式RT-PCR和实时RT-PCR检测蚜虫和锦橙的带毒情况,并分析蚜虫的传毒能力。结果显示,蚜虫中CTV的平均带毒率为0.76~0.84,其中棉蚜的最高,其次为绣线菊蚜、褐色橘蚜和橘二叉蚜。锦橙中各CTV分离株的含量差异不大,与蚜虫传毒效率间无显著相关性;也未发现蚜虫带毒率与其传播CTV能力之间存在相关性。蚜虫体内CTV的含量为5.36×103±2.33×103~2.01×106±3.67×105拷贝,褐色橘蚜中含量最高,其次为棉蚜、橘二叉蚜和绣线菊蚜;且高蚜传能力CTV分离株在褐色橘蚜体内的含量远高于低蚜传能力分离株。表明蚜虫体内CTV的含量可能与蚜虫传毒能力有关。     

Note: Field evaluation ofIsaria fumosorosea in controlling the diamondback moth (Plutella xylostella) in Chinese kale

Twelve entomopathogenic fungi were screened for controlling diamondback moth (Plutella xylostella L.) eggs and larvae in the laboratory. None had any significant ovicidal effect.Isaria fumosorosea CKPF-095 showed the best efficacy in controlling the 2 ^nd instar larvae. It was formulated into a wettable powder at a concentration of 1 × 10⁹ conidia g⁻¹ and used in two field tests. Both tests revealed thatI. fumosorosea CKPF-095 at 1.25 × 10¹³ ha⁻¹ showed as good efficacy as Dipel at 1 × 10¹¹ IU ha⁻¹. http://www.phytoparasitica.org posting June 1, 2008.