Extracts of killedPenicillium chrysogenum Induce resistance against Fusarium wilt of melon     

Hezhong Dong  Yigal Cohen 《Phytoparasitica》2001,29(5):421-430

Dry fungal biomass ofPenicillium chrysogenum (dry mycelium), a waste product of the pharmaceutical industry, was extracted with water and applied to the roots of melon plants before or after inoculation withFusarium oxysporum f.sp.melonis (Font). Seedlings (4–6 days after emergence) treated with either acidic dry mycelium extract (DME) or neutralized dry mycelium extract (NDME) were protected against challenge infection withFom. A single drench with 2–5% DME applied 12–72 h before inoculation provided significant control of the disease compared with water-drenched, challenged seedlings. No protection was seen in plants treated 0–6 h before inoculation or 0–48 h after inoculation. Neither DME nor NDME (0.5–5%) had any effect on fungal growthin vitro, which implied that disease controlin vivo was mediated by induced resistance. The resistance induced by DME protected melon plants not only against race 1,2, but also against the three other races of the pathogen, indicating a race-non-specific resistance againstFom. Both DME and NDME significantly increased peroxidase activity and free L-proline content in seedlings 12 h and 48 h after soil drench, respectively. Resistance to Fusarium wilt was significantly associated with elevated levels of peroxidase activity but not with free L-proline content. Thus, peroxidase might be involved in the defense mechanisms activated by DME or NDME. http://www.phytoparasitica.org posting Aug. 31, 2001.  相似文献   

利用诱导因子抗新疆甜瓜疫霉病的田间效果     

王锐萍 《中国生物防治》2001,17(1):20-22

用化学诱导因子和灭活的生物诱导因子在田间自然条件下诱导了新疆甜瓜产生对疫霉病的整体抗性。1996年的试验结果表明，用化学诱导因子诱导处理，最高诱抗效果可达79．40％，平均诱抗效果在40％以上；生物诱导因子诱导处理，最高诱抗效果为68．2％，平均诱抗效果为30％以上。1997年的试验基本上验证了1996年的结果，化学诱导因子最高诱抗效果可达60％，平均诱抗效果为35．86％，经t测验分析，诱抗效果显著。  相似文献   

Effects of Plant Defence Activators on Anthracnose Disease of Cashew     

A.M.Q. Lopez  J.A. Lucas 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(5):409-420

The plant defence activators acibenzolar-S-methyl (Benzo[1,2,3]thiadiazole-7-carbothioic acid-S-methyl ester, ASM), 2,6-dichloro-isonicotinic acid (DCINA), salicylic acid (SA), and dibasic potassium phosphate (K₂HPO₄) were tested for their ability to protect cashew (Anacardium occidentale) seeds and leaves from anthracnose disease caused by Colletotrichum gloeosporioides. No inhibition of the early stages of pathogen development was caused by concentrations equal to or lower than 1.1mM a.i. ASM, 1.2mM a.i. DCINA, 5mM SA and 50mM K₂HPO₄. Maximum reduction of the disease in detached leaves, without phytotoxic effects, was obtained with 0.07mM a.i. ASM and DCINA, 5mM SA, and 50mM K₂HPO₄, with a time interval of at least 72h between application of the activator and inoculation with the pathogen. On attached leaves, foliar sprays were slightly more efficient than soil drench treatments, with 5mM SA being the most effective treatment, while 50mM SA as well as 0.3mM a.i. ASM and DCINA caused phytotoxic effects. In field-grown plants, protection was conferred by a soil drench of concentrations as low as 12.6M a.i. ASM and DCINA and 2.6mM SA. These concentrations were not phytotoxic suggesting that plant defence activators have potential for control of anthracnose disease in the field.  相似文献   

An Aqueous Extract of the Dry Mycelium of Penicillium chrysogenum Induces Resistance in Several Crops under Controlled and Field Conditions     

Barbara Thuerig  Andres Binder  Thomas Boller  Urs Guyer  Sonia Jiménez  Christina Rentsch  Lucius Tamm 《European journal of plant pathology / European Foundation for Plant Pathology》2006,114(2):185-197

We have examined the effect of Pen, an aqueous extract of the dry mycelium of Penicillium chrysogenum, on plant–pathogen interactions. Pen controlled a broad range of pathogens on several crop plants under greenhouse and field conditions. Pen protected grapevine from downy and powdery mildew (caused by Plasmopara viticola and Uncinula necator), tomato from early blight (caused by Phytophthora infestans), onion from downy mildew (Peronospora destructor) and apple trees from apple scab (caused by Venturia inaequalis) to a similar extent as fungicides such as copper and sulphur or well-known inducers such as benzothiadiazole or β-aminobutyric acid. Pen had no major direct fungicidal effect and is thus supposed to protect plants by activating their defense mechanisms. The raw material for extraction of Pen was available in constant quality, a prerequisite for commercial application. Under certain conditions, Pen caused phytotoxic side effects. The symptoms mostly consisted of small necrotic spots or, more rarely, of larger necrotic areas. The development of the symptoms was dependent on several parameters, including concentration of Pen, the number of applications, the persistence on the plant tissue, the plant species and variety and environmental conditions. In grapevine, a partially purified fraction of Pen was much less toxic than the crude Pen extract, but protected the plants to a similar extent against P. viticola. Our data show that Pen has interesting and unique properties as a plant protection agent, but more research is needed to further reduce its phytotoxic side effects.  相似文献   

硒营养对蛋鸡强制换羽的影响研究     

宋志刚  呙于明 《中国畜牧杂志》2006,42(7):29-32

本试验旨在通过在日粮中添加不同剂量的硒(0、0.05、0.1、0.2mg/kg日粮),研究蛋鸡换羽过程中激素的变化,探讨硒影响强制换羽的机理。试验结果表明:微量元素硒能够影响换羽过程中血浆T3、T4、促黄体生成激素、黄体酮、雌二醇含量,但是硒参与强制换羽与硒对甲状腺激素代谢的影响无关,硒可能是参与了促黄体生成激素、黄体酮、雌二醇的代谢影响了强制换羽的效果。  相似文献   

Isolation of Salmonella Organisms from Commercial Layer Houses Where the Flocks Were Molted with a Wheat Bran Diet     

《The Journal of Applied Poultry Research》2006,15(1):116-121

To develop an alternative method to feed withdrawal for molting layers, 2 flocks consisting of approximately 26,000 commercial laying hens each at 478 (68 wk, flock 1) and 466 (67 wk, flock 2) d of age were reared in an environmentally controlled windowless house and were fed wheat bran (WB) diet. Flock 1 hens were fed WB for 25 d, and flock 2 hens were fed WB for 21 d and then fed a mixture of WB and layer feed (1:1, wt:wt) for the last 4 d of the treatment. After that, the birds in both flocks were fed a normal layer feed. The photoperiod was reduced from 16 to 9 h in both flocks. Most of the birds in both flocks ceased egg production by 10 to 15 d of feeding the WB diets. Egg production in flock 1 gradually increased to 11.4% by 31 to 40 d and 71.4% by 41 to 50 d of the treatment, whereas the egg production in flock 2 hens lagged behind by almost 10 d. The mean egg production from 61 to 140 d exceeded 86% in both flocks. The houses in the farm were naturally contaminated with several serovars of Salmonella, not Enteriditis or Typhimurium. In both flocks with the WB treatment, no marked increase in Salmonella isolation from environmental samples was observed postmolt relative to premolt levels. The study demonstrated that feeding hens WB could be successfully used as an alternative to feed withdrawal to force-rest aging hens while not exacerbating a Salmonella problem in a commercial egg-production setting.  相似文献   

不同处理及pH变化对果胶酶诱导抗病性的影响     

彭霞薇  赵哀梅  白志辉  张洪勋 《中国生物防治》2006,22(3):234-238

从不同处理方法、酶液pH变化等方面对果胶酶诱导黄瓜抗黑星病效能的影响进行了研究。结果表明，在果胶酶的4种不同处理试验中，以全株表面喷雾法处理的黄瓜黄化子叶黑星病的病情指数降低最多，浓度100和200U／ml的诱导防病效果分别为56．34％和64．13％；下胚轴注射、灌根和漫种等3种处理方法的诱导抗病效果均不显著。经果胶酶诱导处理的黄瓜绿苗叶片病情明显降低，而处理叶上部的未处理叶片发病情况与相应对照差别不大。该结果表明，果胶酶诱导黄瓜绿苗抗黑星病的作用属于局部诱导。果胶酶处理次数的增加可增强其诱导抗病效果，并延长诱导抗病时间。酶液pH变化对果胶酶的诱导抗病作用影响显著，pH5．5时，2个浓度的诱导效果最好，分别为51．87％和66．42％。  相似文献   

低浓度玉米小斑病菌C小种毒素培养滤液对玉米叶片过氧化物酶活性的诱导作用   总被引：1，自引：0，他引：1  

商闯  马春红  李运朝  翟彩霞  董文琦  崔四平  侯立白  贾银锁 《中国生物防治》2007,(Z1)

分别用不同低浓度玉米小斑病菌C小种毒素培养滤液处理两种基因型(C103和B37)的同核异质系的玉米叶片,以提高玉米叶片内过氧化物酶(POD)的活性;结果说明:过氧化物酶的活性变化与植物抗病性呈正相关,低浓度C毒素培养滤液本身能够作为激发子来诱导玉米获得抗性,故低浓度C毒素培养滤液作为激发子来诱导玉米的系统获得性抗性具有一定的广适性。对CB37和CC103的处理中,1∶60处理组效果均表现为较好,POD酶活性最高。  相似文献   

拮抗内生细菌与附生细菌及其组合对烟草赤星病的诱导抗性和控病作用   总被引：5，自引：0，他引：5  

易龙  肖崇刚  马冠华  杨水英 《中国生物防治》2007,23(2):165-169

内生细菌菌株Itb162和附生细菌菌株Ata28能有效地抑制烟草赤星病，本试验观测和比较拮抗内生细菌和拮抗附生细菌及其混合菌液对烟草赤星病的控病作用及其对烟草苯丙氨酸解氨酶、多酚氧化酶、过氧化物酶活性的诱导情况及病程相关蛋白的变化。结果表明，内生细菌和附生细菌及其混合菌液都能显著地抑制烟草赤星病，混合菌液处理效果最好。在诱导抗性试验中，经内生细菌和混合菌液处理，烟草体内PAL、PPO、POD活性有不同程度的提高，病程相关蛋白也有量的积累，而附生细菌没有诱导作用。上述试验结果说明内生细菌比附生细菌更易对烟草产生诱导抗性，其混合作用的诱导抗性主要来自于内生细菌。  相似文献   

胚轴切断法诱导棉花抗棉铃虫及其生化机制研究   总被引：1，自引：0，他引：1  

张青文  李萍  王刚  蔡青年 《植物保护学报》1998,25(3):209-212

诱导抗虫棉株对棉铃虫营养代谢功能的影响表明,胚轴切断法结合假单胞杆菌（Ｄ－２２５１）诱导处理的棉株可使棉铃虫相对生长率（ＲＧＲ）、相对取食量（ＲＣＲ）和近似消化率（ＡＤ）明显降低,分别降低２２．９５％、２６．１２％和２７．２３％,仅用胚轴切断法处理的棉株可使ＧＲＧ、ＲＣＲ和ＡＤ分别降低１７．２５％、２１．４４％和４．０９％。对诱导处理棉株体内植物多元酚和抗虫萜烯类的测定结果表明,经过胚轴切断法后,  相似文献