葡萄霜霉病的防治研究

研究了３种新型高效杀菌剂对葡萄霜霉病的防治。霜疫必克，瑞毒霜和甲霜灵对葡萄霜霉病的防治效果均显著，同时也推荐１种新的方法，这种方法是用瑞毒灌根法防治葡萄霜霉病。     

水杨酸诱导桉树抗青枯病的作用及相关酶活性变化

在毒性测定中，1～20mmol水杨酸(salicylic acid，SA)对桉树青枯病菌的生长无抑制作用。通过淋根，1～5mmol的SA可以诱导桉树苗显著地增强对青枯病的抗性，但以5mmol最佳。过氧化物酶(POX)和多酚氧化酶(PPO)的活性，在0．1～5mmol SA范围内，随着浓度的升高相应增强；SA淋根3～9d后挑战接种青枯病菌均能诱导桉树显著地提高对青枯病的抗性，但以间隔5～7d效果最好，且POX和PPO的酶活性与抗病性的变化趋势相符，均在第7天升至最高值，分别比对照高2倍和1倍。POX酶灵敏快速，更能准确地反映植株抗病性的变化；叶片注射SA不能诱导桉树抗青枯病。     

葡萄霜霉病的防治

葡萄霜霉病是葡萄的常见病,也是严重影响葡萄生长发育和果实产量的主要病害.笔者近几年对该病进行了详细观察,并搞了多种防治实验,取得了一些经验,现介绍给读者.     

水杨酸诱导植物抗病性机制的研究进展

阿斯匹林(即乙酰水杨酸,在生物体内可很快转化为水杨酸SA)可治疗人的多种疾病,这是人所共知的.同样,SA在植物体内的生理作用也是多种多样的,如诱导某些植物开花;导致天南星科植物的佛焰花序产热;诱导烟草和黄瓜等植物对细菌、真菌、病毒等多种病害的抗病性.SA是植物体内含量很低的一种小分子化合物,可通过韧皮部运输,对一些重要的代谢过程起调控作用.因此,有人认为可以把它当作一种植物激素来看待[1].目前 ,对SA的研究主要集中在其诱导植物抗病性上. 许多研究表明,SA可以作为诱导因子,在植物抗病反应中起着非常重要的作用.     

水杨酸诱导油茶抗炭疽病的研究

应用水杨酸溶液喷洒油茶叶片可有效诱导植株产生对炭疽病的局部性和系统性抗性.浓度150 mg·L-1诱导抗性效果最好,其对嫩叶的局部诱导病斑减小率为54.15%,对老叶的病斑减小率为61.55%.该浓度的水杨酸溶液喷洒对油茶炭疽病的系统性诱导抗性可使病斑减小率达46.7%;田间试验防治效果达到45.32%.水杨酸诱导油茶产生的局部性抗性可持续20 d而抗性水平无明显下降.扫描电镜显示在诱导处理的油茶叶片上,分生孢子能够萌发,但是芽管的生长受抑制,甚至异常变形卷曲.     

几种杀菌剂防治葡萄霜霉病田间药效试验

霜霉病是葡萄植株普遍发生的一种病害,近年来危害严重。2013年用4种药剂进行了防治葡萄霜霉病的田间药效试验。结果表明78%科博、72%霜脲锰锌、80%烯酰吗啉、72.2%霜霉威都有防治效果。其中78%科博500倍液,80%烯酰吗啉2500倍液的防效更高。     

水杨酸与植物诱导抗病性

水杨酸(SA)被认为是诱导植物抗病反应的重要信号分子之一。许多研究报道：水杨酸参与植物的HR(超敏反应)和SAR(植物系统抗病性)介导的与植物病理相关的PRP(也叫PRS，病程相关蛋白)基因的表达。章就SA与植物抗病性间的关系、SA抗病机理、SA在植物系统抗病性间的信号传递以及SA调节SAR基因表达的分子机理作以综述。     

芳香酸诱导桉树抗青枯病研究

抑菌测定结果表明:在改良的Kelman平板培养基上,1～20mmol的阿魏酸、香豆酸、香草酸、肉桂酸、磺基水杨酸、对羟基苯甲酸和水杨酸钠对青枯病菌的生长没有影响,因此在用水杨酸钠淋根后,植株抗病性的增强是由于桉树苗木产生诱导抗病性的结果,而不是该化合物的直接毒性;浓度为5～10mmol的水杨酸钠均可以获得较强的诱导效果,并以接种前5～7d处理桉树苗的诱导抗病性最强;其它的芳香酸对桉树抗青枯病没有诱导活性.     

3种杀菌剂对葡萄霜霉病的田间防治试验

本文就3种杀菌剂对葡萄霜霉病的田间防治效果进行了评价。70%丙森锌可湿性粉剂和72%锰锌·霜脉可湿性粉剂对葡萄霜霉病均有很好的防治效果。70%丙森锌可湿性粉剂400～600倍液,在第2次药后7d防效均在79%以上,第3次药后14d防效均在81%以上。72锰锌·霜服可湿性粉剂600～800倍液,在第2次药后7d防效均在65肠以上,第3次药后14d防效均在76%以上。35氢氧化铜氯化钙重盐可湿性粉剂防治效果不理想,施药3次后的防效达59%以上.     

几丁聚糖控制月季霜霉病的研究

几丁聚糖是几丁质脱乙酰基后得到的一种氨基多糖。其产品0.5%OS-施特灵可控制月季霜霉病Peronospora sparsa，每隔10天以500倍液连续施药3次，控制效果达80％左右。     

在液体培养系统中诱导桉树抗青枯病的快速测定

采用液体培养方法研究了水杨酸诱导桉树抗青枯病的作用。在液体培养中,用0.5 mM或1.0 mM的水杨酸浸泡桉树幼苗,可以显著地提高幼苗对青枯病的抗性,诱导抗病效果分别为30.4%和60.2%。幼苗浸泡1 d后,即表现较强的抗病性,但以预处理3~5 d适宜。当水杨酸浓度超过3.0 mM或浸泡时间达7 d以上时,幼苗死亡率明显增加。因此,过量的水杨酸对桉树幼苗有毒害作用。液体培养系统操作简单,苗木发病时间仅为盆栽苗木发病时间的1/3或1/2,且容易观察苗木发病情况,可以代替土壤盆栽系统测定水杨酸对桉树苗的诱导抗病效果,也可应用于筛选大量外源物质和生物制剂的诱导抗病作用。     

Application of salicylic acid induces antioxidant defense responses in the phloem of Picea abies and inhibits colonization by Ips typographus

The adaptive plasticity of Norway spruce (Picea abies) against attack by Ips typographus depends on systemic acquired resistance which involves salicylic acid (SA), and an antioxidant system both recognized as valuable stress markers in ecophysiological studies. In the presented field experiment, 100 mM SA was applied to the bark sections of Norway spruce prior to being attacked by bark beetles, in order to study interactions with antioxidants and its significance for mediating stress-tolerance under natural conditions. SA-treatments significantly elevated the total SA levels over the whole sampling period. Total glutathione (tGSH) and total cysteine (tCys) increased by 167% and 80%, respectively, two weeks after treatment, in comparison with controls. In contrast, SA-treatment caused an initial deterioration in total ascorbic acid (tASC) and enhanced the percentage of dehydroascorbic acid (DHA), but activated tASC levels over later sampling dates. The initial bark beetle attack was characterized by a significant decline in total SA levels, which was accompanied by a transient degradation and oxidation of their ascorbate-glutathione system. This initial reaction was significantly alleviated by SA-application and characterized by 175% higher tGSH contents, when compared to moderately-affected untreated trees. One month after pheromone dispensers were placed on trees, an intensification of ascorbate-glutathione system occurred within moderately-affected bark, but to a greater extent after SA-treatment. Total SA levels within SA-treated moderately-affected trees remained at the control level until June. In contrast, strong attack was characterized by a successive increase in total SA up to 252% following SA-treatment in June, whereas a 110% increase of SA was determined within severely affected control-bark. A strong attack was further characterized by a degradation of tGSH and total phenolics (tPH), a moderate increase in tASC and an oxidation of the ascorbate-glutathione pool within untreated bark. In the SA-treated trees the redox state was unaffected by severe colonization and the degradation of antioxidants was significantly alleviated. In addition, SA-treated bark had significantly less entrance holes and exhibited fewer and shorter maternal galleries than control-bark. From this perspective, exogenous SA was successfully implicated as an activator of systemic acquired resistance in Norway spruce, providing tolerance against the complex interactive effects of bark beetle attack and environmental factors.