【作者】 唐保宏；

【导师】 陈捷；

【作者基本信息】 沈阳农业大学 ， 植物病理学， 2003， 硕士

【摘要】 本文首次对应用非生物诱抗剂防治茄子黄萎病进行了系统的研究。（1）通过对几种侯选非生物诱抗剂对大丽轮枝菌和茄子生长的影响的测定，明确了每种诱抗剂的安全使用浓度范围以及它们在苗期对黄萎病的防治效果，从中筛选出几种效果较好的诱抗剂；（2）明确了PPO、POD、PAL等防御酶系在茄子黄萎病诱导抗性中的变化规律；（3）Ca²⁺、SA在茄子黄萎病系统诱导抗性中起着重要的信号传导作用；（4）诱抗剂对茄子根系活力有促进作用，对根际微生物及其动态变化有显著的影响；（5）环境因子中温度、湿度和土壤酸度对诱抗剂的诱导效果有显著影响；不同的诱抗剂对不同抗性背景的茄子诱导抗性的效果不同，中抗品种效果较好，抗病品种诱抗效果较稳定，感病品种诱抗效果受环境影响较大；诱抗剂处理的时期对诱抗剂的效果也有显著影响，在茄子不同生育期进行诱导处理防效存在显著差异；（6）诱抗剂的浓度和使用方法对诱抗效果有不同的影响，诱抗剂复合使用比单一使用或一次性诱导效果好。 研究表明氟乐灵(＜3μL·L^-1)、过氧乙酸(＜100μL·L^-1)、过氧化氢(＜100μL·L^-1)、草酸及草酸钾(＜40mmol·L^-1)、磷酸氢二钾(＜100mmol·L^-1)和水杨酸(＜5mmol·L^-1)对茄子黄萎病病菌的生长没有显著影响，对茄子种子萌发及茄苗生长也没有抑制作用。各种诱抗剂对茄子黄萎病均有一定的防治作用，其中过氧乙酸、氟乐灵、草酸钾和水杨酸的防治效果较好，磷酸氢二钾的防效较差。用过氧乙酸、氟乐灵、草酸钾和水杨酸浸种处理，对茄子黄萎病诱导抗性的防效最大值在60-90％，持久期都在22天以上。 诱抗剂处理后茄子的根系活力相对于对照都有一定程度的提高，这可能是诱抗剂增强茄子对黄萎病的抗性的原因之一，但不是主要因素。根际微生物区系易受多种因素影响而发生动态变化，其中以根系分泌物的影响为主。诱抗剂处理对茄子根际微生物区系有不同程度的影响，根际真菌在生育期前期和中期较为丰富，在调查的多数时间诱抗剂处理根际真菌数量显著多于对照处理；根际细菌和放线菌在中期最为丰富，在调查后期，过氧乙酸和氟乐灵诱导处理的茄子根际真菌、细菌和放线菌数量显著高于对照处理，草酸和过氧化氢诱导处理在部分阶段根际细菌和放线菌数量低于对照。 通过对过氧乙酸诱导处理及接种病菌前后叶片细胞Ca²⁺的动态变化发现Ca²⁺信号系统在茄子对黄萎病的系统诱导抗性起重要作用，总钙含量和挑战接种后结合钙比例与茄子抗性相关。过氧乙酸诱导后过氧化氢酶（CAT）活性都有一次显著的升高，接种后过氧化氢酶活性一般显著低于对照，这种中文摘要变化也表明活性氧和氧化突增可能是系统诱导抗性的前提之一，HZOZ和水杨酸可能是过氧乙酸诱导茄子对黄萎病产生系统诱导抗性的重要信号物质。 PAL、PPO、POD、SOD在茄子黄萎病系统诱导抗性中也起着重要的作用。过氧乙酸诱导处理显著增强了这些防御酶系的活性。但是防御酶系活性一般在病原菌挑战接种之后才显著升高，或者在诱导处理初期有短暂的升高，这主要由于植株需要被诱导敏化。活性氧对系统诱导抗性的产生起重要作用，木质素合成和酚类物质的代谢是茄子黄萎病诱导抗性的重要机制。过氧乙酸诱导处理前后p一1，3一葡聚糖酶活性的增加不显著。 影响诱抗剂作用效果的因素中，温度、空气相对湿度和土壤pH值都有显著的影响。诱抗剂过氧乙酸和氟乐灵一般在20℃一25℃防效较好，30℃防效均较差。温度主要通过影响挑战接种而制约防效，诱导处理时的温度对诱导抗性的效果也有一定的影响。相对湿度对诱抗效果的影响也比较明显。过氧乙酸和氟乐灵在相对湿度较高时（RH75一80%和90一95%）下防效较好，而相对湿度较低时（RH6O一65%）防效稍差。土壤pH对过氧乙酸和氟乐灵的影响不同。在pH 5.8一8.0时土壤酸碱度与过氧乙酸的诱抗效果呈显著的负相关性。氟乐灵的防效受土壤pH的影响不如过氧乙酸明显，但总的趋势是在pH较高（弱碱性）的土壤中防效稍好。茄子的生育期对诱抗剂诱导处理的效果有显著的影响，进行种子处理和幼苗期处理的诱抗效果比成株期好，但生育期前期处理到成株期防效下降，成株期诱导处理和种子处理和幼苗处理有互补性。诱抗剂在不同抗性的茄子品种上的诱抗效果不同。供试诱抗剂在抗病性较强的品种辽茄五号和西安绿茄上诱抗效果一般都比较好，而在抗病性较差的辽茄四号上防效稍差，而且不同诱抗剂间存在较大的差异。 诱抗剂的使用剂量和方法对诱导效果的影响很大。氟乐灵和过氧化氢的防效一般随着使用浓度的增加而增加，过氧乙酸和草酸钾的防效在一定浓度范围内随处理浓度而增加，但在较高使用浓度下防效反而降低。诱抗剂复合使用可以增强诱抗效果。不同诱抗剂适用不同的使用方法，过氧乙酸、过氧化氢浸种处理的防效较好，氟乐灵、草酸钾、草酸拌土处理比浸种处理的诱导效果好，水杨酸用两种方法处理诱抗效果差异不大。更多还原

【Abstract】 Efficacy and mechanism of systemic acquired resistance to Verticillium wiltin eggplant induced by seven chemical inducers were studied systemically. Theresearch gave the following results:(1)Measurement of colony diameter and dryweight of Verticillium dahliae culture showed that within certain concentrationsthese chemicals had no significant influence on mycelial growth of thepathogen.These inducer candidates were safe to eggplant. Several of them greatlyreduced the disease caused by Verticillium dahliae Kleb and could be goodinducers.(2)Function of defense enzymes such as PPO, POD, PAL ,SOD andCAT in SAR was made clear.(3) Ca2+, H2O2 and SA were most probable thesignals of systemic acquired resistance to Verticillium wilt ineggplant.(4)Chemical inducers promoted root activity of eggplant and hadsignificant effect on microbe population and dynamics(of bacteria, fungi andactinomycetes) in rhizosphere of treated eggplants.(5)Temperature, relativeactivity and pH values of soil were important factors for efficacy of chemicalinducers; each inducer has its optimum environment requirement. Efficacy ofinducers was also different in eggplant cultivars of different resistancebackground. Efficacy in resistant cultivars are more stable and less affected byenvironmental factors, and was best in partially resistant cultivar. (6) Magnitudeof disease reduction depended on inducer concentration and mode of application.Combined use of different inducers or applying the same more than once showedbetter effect than applying an inducer just once.This research found that at low concentrations trifluralin(<3μL.L-1),peracetic acid(<100μL.L-1), hydrogen peroxide(<100μL.L-1),oxalic acid(<10mmol.L-1), potassium oxalate(<40mmol.L-1), di-potassium hydrogen phosphate((<100mmol.L-1), and salicylic acid(<5mmol.L-1) didn’t inhibit growth of the pathogen, and seed germination or seedling growth was not stunted. All of the seven inducers have disease control effect to some extent. Di-potassium hydrogen phosphate was least efficient. Trifluralin, peracetic acid, oxalic acid, potassium oxalate and salicylic acid showed high efficiency in control of Verticillium wilt, seed soaking with them individually reduced disease severity by 60-90% and eggplants could be protected for over 22 days.Root activity of plants treated with inducers increased slightly,which was helpful for enhancing eggplant resistance. Population of rhizospherial microorganisms was exposed to complicated factors among which root secretion was the most vital. Rhizospherial microorganisms of inducer-treated plants differed significantly from that of control. Fungi were most rich during early and middle stage of growth season, population of rhizospherial fungi of induced plants was much richer than the nontreated in most of the time. Rhizospherial bacteria and actinomycetes were rich in middle growth season.In the later period of investigation amounts of fungi,bacteria and actinomycetes in rhizosphere of peratic acid and trifluralin treated plants were much greater than the nontreated, but that of oxalic acid and hydrogen peroxide treatment were poorer.Change of total and soluble calcium concentrations pre- and post inoculation suggested that Ca2+ signal system was important in systemic induced resistance to Verticillium wilt in eggplant. Relative activity of catalase increased greatly soon after peratic acid treatment in leaves of different ages, but after challenge inoculation the activity was lower than the nontreated. The fluctuation of catalase indicates that reactive oxygen species(ROS) and ROS burst may be the pioneer of resistance signal transduction. H2O2 and SA could be important signal of SAR.Defence enzymes PAL,PPO,POD and SOD played important roles in induced resistance to Verticillium wilt. Peratic acid treatment dramatically increased relative activity of these enzymes. The activity of some of them(eg. POD , SOD) increased transiently soon afte更多还原