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1.
自山东泰安及烟台地区的小麦全蚀病菌中提取到两种类型颗粒,一类是球形至多边形的病毒颗粒,直径在22~45毫微米之间,多数为27~32毫微米;另一类是棒状颗粒,长度为40~185毫微米×16毫微米,平均108×16毫微米,提取的球形病毒具有核蛋白的典型吸收光谱,最大和最小吸收值的波长分别在260毫微米和240毫微米,A260/240=1.24,A260/280=1.62。以烟台株病毒制备的抗血清,分别与烟台及泰安株病毒在琼脂免疫双扩散中作用均产生沉淀线,表明二者具有共同的血清型。烟台株病毒经苯酚抽提后的核酸样品最大吸收波长是260毫微米,最小是230毫微米,经聚丙烯酰胺-琼脂糖凝胶电泳分离为两条迁移率相近的带,表明此病毒有两个基因片断,在分类上属于需要两个dsRNA片断才能复制的等轴dsRNA真菌病毒。其外壳蛋白经测定含分子量70,000的多肽。<>br从浙江、湖北等11个省(市)的12株全蚀病菌中均提取到了病毒,比较了各菌的菌落颜色,生长速度和病毒浓度。 相似文献
2.
The bioactive metabolites of someAllium plants, all exhibiting interesting pharmacological activities, were tested for their attractive/repellent activity against
saw-toothed grain beetle,Oryzaephilus surinamensis (L.), rice weevil,Sitophilus oryzae (L.), and rust-red flour beetle,Tribolium castaneum (Herbst), insects infesting the stored-products.
The data obtained showed significant repellent effect of the thiosulfinates againstS. oryzae.
Part 6 in the series “Chemistry of the genus Allium”. 相似文献
3.
The bioactive metabolites of someAllium plants, all exhibiting interesting pharmacological activities, were tested for their attractive/repellent activity against saw-toothed grain beetle,Oryzaephilus surinamensis (L.), rice weevil,Sitophilus oryzae (L.), and rust-red flour beetle,Tribolium castaneum (Herbst), insects infesting the stored-products. The data obtained showed significant repellent effect of the thiosulfinates againstS. oryzae. 相似文献
4.
Yared Tesfai Tewoldemedhin Mark Mazzola Wilhelm J. Botha Christoffel F. J. Spies Adéle McLeod 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(2):215-229
Several species of fungi and oomycetes including Fusarium, Rhizoctonia, Phytophthora and Pythium have been reported as root pathogens of apple where they contribute to a phenomenon known as apple replant disease. In South
Africa, little is known about specific species in these genera and their pathogenicity toward apple. Therefore, these aspects
were investigated along with the development and optimization of qPCR tests for detection and quantification of the most virulent
oomycete species. In eight investigated orchards, the oomycete Phythophthora cactorum was widely distributed, while nine Pythium species were differentially distributed among the orchards. Pythium irregulare was the most widely distributed and the most virulent species along with P. sylvaticum, P. vexans and Ph. cactorum. Seven binucleate Rhizoctonia anastomosis groups (AGs) were also differentially distributed among the orchards, with the majority appearing to be non-pathogenic
while certain AG-I and AG-F isolates exhibited low virulence on apple. In the genus Fusarium, F. oxysporum was widely distributed, but isolates were non-pathogenic. Fusarium solani and F. avenaceum were less frequently encountered, with only some isolates having low virulence. qPCR data obtained from seedling roots inoculated
with the most virulent Pythium species (P. irregulare, P. sylvaticum and P. vexans) and the genus Phytophthora were not always reproducible between trials, or isolates of the same species. In general, seedling growth inhibition was
associated with the presence of a low amount of pathogen DNA (±40 fg μl−1 to 2 pg μl−1) in roots. Pythium irregulare, although having the lowest DNA concentrations in roots, was the only species for which a significant negative correlation
was found between seedling weight and pathogen DNA concentration. 相似文献
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瑞香素对蚜虫生物活性的研究 总被引：19，自引：2，他引：19
瑞香狼毒(StellerachamaejasmeL.)的天然产物瑞香素对农业上重要的几类蚜虫具有很高的触杀作用和较好的拒食作用.24h瑞香素对棉蚜、桔蚜和烟蚜毒杀作用的LD50分别为29.48±1.55、30.75±1.50和95.88±2.06μg/g,拒食作用的AFC50分别为0.4664±0.0137、0.4219±0.0213和0.5847±0.0172g/L.经回归和相关分析,处理浓度与作用效果(毒杀与拒食)相关性均达到极显著或显著水平.瑞香素在田间防治棉蚜效果显著. 相似文献
7.
Ping Li Yan Pei Xianchun Sang Yinghua Ling Zhenglin Yang Guanghua He 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(4):533-543
McCHIT1 chitinase (DQ407723), a class I secretory endochitinase from bitter melon (Momordica charantia), had been demonstrated to enhance resistance against Phytophthora nicotianae and Verticillium wilt in transgenic tobacco and cotton. In order to obtain disease-resistant transgenic rice, McCHIT1 was transformed into a restorer line JinHui35 (Oryza sativa subsp. indica) by using the herbicide-resistance gene Bar as the selection marker. Transgenic rice lines and their progenies overexpressing the McCHIT1 gene showed enhanced resistance to Magnaporthe grisea (rice blast) and Rhizoctonia solani (sheath blight), two major fungal pathogens of rice. McCHIT1-transgenic rice confirmed the inheritance of the transgene and disease resistance to the subsequent generation. The T2 transformants exhibited significantly increased tolerance to M. grisea, with a 30.0 to 85.7 reduction in disease index, and R. solani, with a 25.0 to 43.0 reduction in disease index, based on that of the control as 100. These results indicated that over-expression
of the McCHIT1 gene could lead to partial disease reduction against these two important pathogens in transgenic rice. 相似文献
8.
Stéphanie Diallo Xavier Latour Anne Groboillot Bruno Smadja Patricia Copin Nicole Orange Marc G. J. Feuilloley Sylvie Chevalier 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(2):349-354
Dickeya spp. and Pectobacterium atrosepticum are major pathogens of potato. Current methods to detect these soft-rotting bacteria require separate identification steps.
Here we describe a simple method allowing simultaneous detection of both pathogens based on multiplex PCR. The sensitivity
of the primer sets was first examined on purified genomic DNA of the type strains Dickeya chrysanthemi 2048T and P. atrosepticum 1526T. The specificity and detection limits of the primer sets were successfully tested on 61 strains belonging to various Dickeya and Pectobacterium species, on artificially inoculated and on naturally contaminated potato plants. This new method provides a gain in time
and materials, the main advantages for large-scale processes such as pathogen-free seed certification. 相似文献
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Judy A. Thies Jennifer J. Ariss 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(4):545-550
Genetic resistance to Meloidogyne incognita in pepper (Capsicum annuum) has been well characterised for the N and Me3 resistance genes. However, there are no studies comparing the effects of these two genes directly or investigating the combined
effects when both genes are present together. Several studies were undertaken to investigate the relationship of the N and Me3 gene systems to one another and to assess whether these two genes are allelic or truly separate genes. Two genotypes homozygous
for the N gene (‘Carolina Wonder’ and ‘Charleston Belle’) and two genotypes homozygous for the Me3 gene (HDA 149 and PM 687) were compared in a replicated greenhouse test for reaction to M. incognita race 3. There were no significant differences between the resistant reactions of genotypes possessing the N or Me3 gene. Allelism tests were performed using the F2 populations of the parental genotypes HDA 149 × ‘Charleston Belle’ and HDA
149 × ‘Carolina Wonder’. The results of these studies clearly show the N and Me3 genes to be distinct, separate dominant resistance genes conferring resistance to M. incognita race 3 and not alleles of the same gene. 相似文献
12.
Koji Tanina Motoaki Tojo Hirotaka Date Hideo Nasu Shinji Kasuyama 《Journal of General Plant Pathology》2004,70(3):188-191
Severe rot was found at the base of leaves and stems of chingensai (Brassica campestris L. chinensis group) in Okayama Prefecture in 2000. The causal fungi were morphologically identified as Pythium ultimum Trow var. ultimum and P. aphanidermatum (Edson) Fitzpatrick. This is the first report of rot caused by Pythium species on chingensai. We named this disease Pythium rot of chingensai. 相似文献
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A. S. Abdel-Razek 《Anzeiger für Sch?dlingskunde》2003,79(1):108-111
The relationship between Xenorhabdus nematophilus and Photorhabdus luminescens, the bacterial symbionts of the entomopathogenic nematodes Steinernema carpocapsae and Heterorhabditis bacteriophora, against the diamondback moth, P. xylostella (L.), pupae showed the pathogenic capability of P. luminescens to be over that of X. nematophilus. They gave 60 and 40% mortality with LC50 values of 5×104 and 5.5×105 cells/ml, respectively.The number of bacterial cells influences the rate of killing the pupae of P. xylostella and a direct correlation between mortality of the pupae, percentage of deformed adults and the spraying dose with significant differences were observed. An inverse correlation found between the no. of eggs laid/female, percentage of hatching, adult survival and the spraying dose. These bacterial effects have been attributed to different toxic bacterial enzymes which damage the haemocytes and inhibit activation of the humoral immune system of the insect. 相似文献
15.
柰李黑斑病(Xanthomonas campestris pv.pruni(Smith) Dye)是洞庭湖区柰李(Prunus salicina var.cordata)上的一种主要病害,主要为害柰李果实,引起黑斑,导致落果,亦为害枝梢,引起流胶枯梢,为害叶片则引致穿孔。重病果园减产达70%以上。为了探讨此病的侵染机制,为培育抗病品种提供依据,特开展此项研究。 相似文献
16.
A. S. Abdel-Razek 《Anzeiger für Sch?dlingskunde》2003,76(4):108-111
The relationship between Xenorhabdus nematophilus and Photorhabdus luminescens, the bacterial symbionts of the entomopathogenic nematodes Steinernema carpocapsae and Heterorhabditis bacteriophora, against the diamondback moth, P. xylostella (L.), pupae showed the pathogenic capability of P. luminescens to be over that of X. nematophilus. They gave 60 and 40% mortality with LC50 values of 5×104 and 5.5×105 cells/ml, respectively.The number of bacterial cells influences the rate of killing the pupae of P. xylostella and a direct correlation between mortality of the pupae, percentage of deformed adults and the spraying dose with significant differences were observed. An inverse correlation found between the no. of eggs laid/female, percentage of hatching, adult survival and the spraying dose. These bacterial effects have been attributed to different toxic bacterial enzymes which damage the haemocytes and inhibit activation of the humoral immune system of the insect. 相似文献
17.
Es konnten 132Bacillus-Stämme isoliert und gegenüber7 Rhizoctonia-solani- und 6Pythium-Stämmen auf Antagonismusin vitro untersucht werden. Die gefundenen Antagonisten hemmten die Pilzisolate unterschiedlich stark, so daß Gemische von Antagonisten für die Praxis zu empfehlen sind.There were 132Bacillus-strains isolated and tested for antagonism against 7 strains ofRhizoctonia solani and 6 strains ofPythium spp. The isolated antagonists didn't show a uniform effect against the tested strains ofRhizoctonia solani andPythium spp. For an application in practice it will be better to use a mixture of antagonists.
Mit 4 Abbildungen und einer Tabelle 相似文献
Mit 4 Abbildungen und einer Tabelle 相似文献
18.
Es konntenBacillus-Isolate gefunden werden, die sich in Keimungsversuchen an Samen als antagonistisch gegenüberPythium aphanidermatum undRhizoctonia solani erwiesen. Die Versuche wurden mit Bohnen- und Gurkensamen durchgeführt. Die wirksamsten Antagonisten konnten in infizierter Erde Auflaufraten bei Gurken von 40–60% erzielen.Die Wirksamkeit der Antagonisten an Bohnen war niedriger, hier lagen die Keimraten kaum höher als 30%. Offenbar hängt die Wirksamkeit derBacillus-Antagonisten von der Fähigkeit ab Antibiotika zu produzieren und in Konkurrenz zu anderen Mikroorganismen zu treten. 相似文献
19.
作者对黑缘红瓢虫亚种(Chilocorus(rubidus abc.)tristis (?)a(?)der.进(?)过冷却点以及耐寒力的测定。结果表明:成虫的过冷却点为-11.83℃;在2—0℃、-2—-4℃、-6—-8℃和-9—-10℃下,30天后的死亡率分别为3.33％、15.00％、70.00％和91.67％,后两种处理的致死中期分别为13.4和5.5天。 相似文献
20.
1.乌头[Aconitum Carmichaelii Debx)白绢病[Sclerotium rolfsii Sacc],菌核在10～47℃内萌发,以25～30℃为宜,48℃不萌发;菌丝在10～42℃内生长,30～33℃生长最好,42～47℃为抑制温度;pH值5～6发育最好,2.4以下,8以上生长不良,pH值11发育受抑;土壤含水量在10～80%均萌发,20～30%发育最好。 2.白绢病的侵染源为土壤、种根、肥料; 3.病害发生初期在4月底或5月上旬,气温18.2～21.4℃,地温18.7℃;盛期6～7月,气温24～27℃,地温29.5℃,8月底病终止。 4.连作病重,轮作5年以上病轻,紫色土病重,石屑土病轻;阳坡病重,阴坡病轻;海拔低病重,海拔高病轻。 相似文献