共查询到19条相似文献，搜索用时 312 毫秒
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人参锈腐病参根体内若干生物化学变化 总被引：7，自引：1，他引：7
对人参锈腐病[Cylindrocarpon destructans (Zinss) Scholten)的病根组织和健根组织进行了多种有机物的分析。结果表明,在病根中人参总皂甙、淀粉、总糖和6种氨基酸的含量减少。但脂肪酸、木质素、还原糖和10种氨基酸的含量比健参根增加。 相似文献
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辣椒品种营养组成和绒毛特征与抗侧多食跗线螨的关系 总被引：1，自引：1，他引：0
利用螨量比值法,研究11个辣椒品种叶片茸毛密度和长度、叶绿素含量、可溶性糖含量、可溶性蛋白质含量和游离氨基酸含量与抗侧多食跗线螨Polyphagotarsonemus latus (Bank)的关系,以期阐明辣椒品种对侧多食跗线螨的抗性机制.结果显示,螨量比值与辣椒品种叶片绒毛密度、单位面积叶绿素含量和可溶性糖含量呈显著负相关,相关系数分别为-0.8455、-0.8851和-0.6712;与游离丝氨酸含量呈极显著负相关,相关系数为-0.829;与游离氨基酸总量和可溶性蛋白质含量无显著相关性.研究表明,辣椒品种对侧多食跗线螨的抗性与叶片叶绿素、可溶性糖、游离丝氨酸含量及叶片绒毛密度有关. 相似文献
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人参红皮病根部生物化学变化及病参质量综合评价 总被引：2，自引：0，他引：2
对人参红皮病根部和健参根体内多种有机物含量的测定结果表明,病参根比健参根体内的总皂甙、淀粉、总糖含量减少,而还原糖、果胶质含量增加。所测病根体内17种氨基酸总含量、必需氨基酸含量比健根减少。病根无机元素Fe、Al、Mn的含量比健根显著增加而导致参根质量下降。红皮病的危害主要是降低人参产品的质量。严重度Ⅱ级以上的病参,使鲜参、红参的商品等级下降2~3级,其内在质量也显著降低。 相似文献
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水稻品种对白背飞虱的抗性机理 总被引：6，自引：2，他引：6
对水稻品种抗白背飞虱的抗生反应及植株体内化学成分与抗性关系进行了探讨。结果表明，在抗生性反应中，抗性品种Ptb33、N22、Mudgo、包选2号、南京14、HA79317使白背飞虱取食量减少、成活率降低、繁殖少、发育慢等一系列不良现象，导致种群数量下降。抗性水稻体内游离氨基酸总量、天门冬氨酸、苏氨酸及可溶性糖等营养成分含量和白背飞虱取食率极相关，相关系数为0．809－0．916。抗、感植株体内单宁、草酸含量没有显著差异，而次生代谢物苯酚含量却差异明显。因此，抗性水稻体内游离氨基酸总量及可溶性糖等含量低和苯酚含量高可能是抗生性主要因素之一。 相似文献
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水稻紫杆症状的病原问题 总被引：1，自引：0，他引：1
紫杆症状又称紫杆病、紫鞘病、黑骨。近几年来在我国稻区普遍发生,特别是水稻抽穗后遇到高温干旱,紫杆会大量地暴发,其势之猛为其它病虫害所不及。笔者在福州市科委的资助下,于1980年下半年从事“跗线螨与紫杆症状产生原因的探讨”专题工作。发现水稻品种不同其发病的差异相当大,选育抗“紫杆”的水稻品种对于控制紫杆症状的蔓延是一项行之有效的措施。 相似文献
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水稻紫秆病的调查研究 总被引：1，自引：0，他引：1
水稻紫秆病近年来从次要病害逐渐上升为主要病害,每年都有发生和危害。从福建、江西、浙江、江苏四省的局部地区调查,此病异名多,如稻螨褐鞘病、黑骨、水稻紫鞘症、紫鞘黄叶病、紫秆症等。现将对此病的调查结果简述如下: 相似文献
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跗线螨为害水稻,1974年首先由广西浦北县病虫测报站发现,以后广东、福建、湖南、湖北、浙江、江苏、上海等省市也陆续发生。跗线螨与水稻“紫杆病”的关系,众说纷云,有人认为跗线螨为害引起“紫杆病”。有人则认为“紫杆病”是由叶鞘腐败病所引起的,由跗线螨传播病原菌。近年来,我们对水稻上的 相似文献
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水稻紫鞘病是我国南方稻区生产上的一个新问题,发生面广,为害较重。经1978~1984年的研究,找到了引起紫鞘的病原茵是Acrocylindrium oryzae。带菌种子是本病的主要初次侵染来源;保存在干燥状态下的病稻草也有传病作用,稻田后期的某些虫、螨,可以传播病菌。紫鞘病病原菌的主要侵染方式是系统侵染。水稻孕穗期喷雾接菌,也能形成紫鞘,但注射法伤口接种时,大多形成虎纹斑烂鞘。因此,紫鞘是水稻叶鞘腐败病的又一种典型症状。病菌生长与产生孢子的适温为25~30℃。孕穗期接菌,其潜育期:30℃为1天,25~28℃为2天,23℃为3天,19℃为4天。 相似文献
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水稻褐鞘症发生原因的进一步探讨 总被引：3，自引：0，他引：3
为进一步探讨水稻褐鞘症的发生原因,本试验设室内人工接种和室外田间小区喷药防治两项处理。人工接种分设接螨、接菌、接螨加接菌和对照4个处理组;田间小区喷药防治则分设喷杀螨剂(双甲脒)和杀菌剂(多菌灵、井岗霉素)两个处理组。获得如下结果: 1.接螨组和接螨加接菌组的病株率分别为89.54％、99.14％;病情指数分别为57.84、38.86;单株带螨量分别为20.74头、12.6头(均包括卵粒)。接菌组和对照组的病株率分别为31.98％、15.36％;病情指数分别为5.98、2.91;单株带螨量分别为1.85头、0.06头(均包括卵粒)。 2.田间喷施杀螨剂(双甲脒)小区比喷施杀菌剂(多菌灵)小区螨发生期推迟15天,单株带螨量降低(分别为18.5头、8.2头)、防治效果较高(分别为51.8％、29.46％)。以上证明斯氏狭跗线螨(Steneotarsonemus spinki Smiley)为华南地区水稻褐鞘症发端的祸首,只要防螨得宜,稻褐鞘症也就可大为减轻。 相似文献
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Effects of Elevated Atmospheric CO(2) Concentration on the Infection of Rice Blast and Sheath Blight
ABSTRACT The effect of elevated atmospheric CO(2) concentration on rice blast and sheath blight disease severity was studied in the field in northern Japan for 3 years. With free-air CO(2) enrichment (FACE), rice plants were grown in ambient and elevated ( approximately 200 to 280 mumol mol(-1) above ambient) CO(2) concentrations, and were artificially inoculated with consist of Magnaporthe oryzae. Rice plants grown in an elevated CO(2) concentration were more susceptible to leaf blast than those in ambient CO(2) as indicated by the increased number of leaf blast lesions. Plants grown under elevated CO(2) concentration had lower leaf silicon content, which may have contributed to the increased susceptibility to leaf blast under elevated CO(2) concentrations. In contrast to leaf blast, panicle blast severity was unchanged by the CO(2) enrichment under artificial inoculation, whereas it was slightly but significantly higher under elevated CO(2) concentrations in a spontaneous rice blast epidemic. For naturally occurring epidemics of the sheath blight development in rice plants, the percentage of diseased plants was higher under elevated as opposed to ambient CO(2) concentrations. However, the average height of lesions above the soil surface was similar between the treatments. One hypothesis is that the higher number of tillers observed under elevated CO(2) concentrations may have increased the chance for fungal sclerotia to adhere to the leaf sheath at the water surface. Consequently, the potential risks for infection of leaf blast and epidemics of sheath blight would increase in rice grown under elevated CO(2) concentration. 相似文献
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Pedro Laborda Xian Chen Guichun Wu Suyan Wang Xiaofeng Lu Jun Ling Kaihuai Li Fengquan Liu 《Plant pathology》2020,69(5):838-848
Although rice is one of the most cultivated, consumed, and essential crops worldwide, it is highly susceptible to a wide range of bacterial and fungal pathogens that significantly reduce the production and quality of rice. Recently, our research group reported that the plant growth-promoting rhizobacterium Lysobacter gummosus OH17 was able to enhance the ethylene levels in Oryza sativa ‘Nipponbare’ plants at the late interaction stages. In this work, L. gummosus OH17 was found to be capable of inducing the overexpression of relevant genes of the jasmonic acid and ethylene transduction pathways in Nipponbare plants, such as OsACC, OsACO, OsERF3, and OsLOX, which resulted in the up-regulation of a number of pathogenesis-related proteins. The observed metabolic effects enhanced the disease resistance of rice against the three most devastating rice pathogens: Magnaporthe oryzae causing rice blast, Rhizoctonia solani causing rice sheath blight, and Xanthomonas oryzae pv. oryzae causing bacterial leaf blight. Furthermore, it was shown that L. gummosus OH17 also enhanced ethylene production levels in other O. sativa varieties from both the japonica and indica subspecies. Here, we report for the first time the metabolic alterations produced by plant growth-promoting rhizobacterium L. gummosus OH17 at the late interaction stages and how these alterations induce systemic resistance. 相似文献
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Elzbieta G Magnucka Yoshikatsu Suzuki Stanislaw J Pietr Arkadiusz Kozubek Robert Zarnowski 《Pest management science》2009,65(10):1065-1070
BACKGROUND: Cycloate inhibits the biosynthesis of very‐long‐chain fatty acids, the essential constituents of plant waxes and suberin. Fatty acids also serve as precursors of aliphatic carbon chains in resorcinolic lipids, which play a fundamental role in the plant defence system against fungal pathogens. In this study, the effect of cycloate on the biosynthesis of 5‐n‐alkylresorcinols in rye seedlings (Secale cereale L.) grown under various light and thermal conditions was examined. RESULTS: The content of alkylresorcinols biosynthesised in rye was generally increased by the herbicide in both green and etiolated plants. The presence of cycloate also affected patterns of alkylresorcinol homologues in plants grown at 15 and 22 °C; very‐long‐side‐chain compounds were less abundant, whereas both short‐chain saturated and unsaturated homologues were generally accumulated. No cycloate‐related effects caused by homologue pattern modifications were observed at elevated temperature. CONCLUSION: This study extends present understanding of the mode of action of thiocarbamate herbicides. Cycloate markedly affected the biosynthesis of very‐long‐side‐chain resorcinolic lipids in rye seedlings, confirming the existence of parallels in both fatty acid and alkylresorcinol biosynthetic pathways. The observed cycloate‐driven accumulation of 5‐n‐alkylresorcinols may improve the resistance of cereals to infections caused by microbial pathogens. Copyright © 2009 Society of Chemical Industry 相似文献
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P. Lakshmanan 《Phytoparasitica》1993,21(1):63-68
A new sheath rot disease of rice incited byCochliobolus lunatus (anamorph:Curvularia lunata) was first observed on rice cultivars at the end of the dry season (April and May) in 1990. Nearly 7% of rice plants at boot leaf stage showed typical sheath rot symptoms. Panicles emerging from diseased plants were mostly black. Six improved cultivars and five breeding lines derived from the wild riceOryza officinalis were completely free of the disease under both natural and artificial infection conditions. These genetic stocks with resistance to sheath rot can now be utilized in breeding programs. 相似文献
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为了探究植保无人飞机喷施30%苯甲·丙环唑微乳剂对稻瘟病、纹枯病和稻曲病的田间防治效果,以及对水稻生长的影响,为植保无人飞机施药的推广提供科学依据,在水稻分蘖末期和破口期采用植保无人飞机进行药剂喷施防治水稻主要病害试验。结果表明:在减量25%的情况下,植保无人飞机喷施30%苯甲·丙环唑微乳剂对纹枯病病株和病情指数的防治效果分别为71.33%和82.72%,对稻瘟病病穗和病情指数的防治效果分别为76.36%和80.41%,对稻曲病病穗和病情指数的防治效果分别为71.11%和79.25%。该施药方式对水稻中后期主要病害防治效果均优于对照药剂和人工施药的防治效果。 相似文献
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Invertase Activities in Sheath-blight Infected Rice Selection Lines and Fungus Culture Filtrates 总被引：2，自引：0，他引：2
Infection of rice plants with Rhizoctonia solani, the sheath blight fungus, at the flowering stage resulted in an increase in acid invertase activity. Activity of the invertase(s)
with optimum pH at 3.5 and 4.5 was higher in the susceptible plants compared to resistant plants. Healthy control plants had
no change in invertase activity. An invertase of fungal origin produced in sheath blight fungus culture filtrates had an optimum
acidic pH of 3.5. The increase in invertase activity observed in the later stages of infection in the susceptible plants compared
to the resistant plants demonstrated a relation to fungal growth. These results suggested that the fungus produced an invertase
for the hydrolysis of sucrose that resulted in alterations of source-sink relationships in the colonized cells. Thus, the
increased invertase activity in the susceptible plants regulated the ratio of hexose to sucrose. This observation is further
supported by the lack of a significant invertase increase in the resistant plants.
Received 14 July 1999/ Accepted in revised form 9 December 1999 相似文献
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秸秆还田对水稻根际微生物多样性和水稻纹枯病发生的影响 总被引：1，自引：0，他引：1
为探究稻麦轮作模式下秸秆还田对水稻根际微生物多样性与水稻纹枯病发生的影响,本研究采用Illumina测序技术结合生物信息学比较分析了秸秆还田与不还田处理的水稻根际微生物群落多样性差异,并采用实时荧光定量PCR （real-time fluorescent quantitative PCR,RT-qPCR）对这2种稻田土壤中水稻纹枯病菌Rhizoctonia solani含量进行测定,并采用随机五点取样法调查稻田中水稻纹枯病发病率和病情指数。结果表明,秸秆还田后水稻根际细菌群落Chao1丰富度指数和Shannon多样性指数均有所增加,分别增加14.42%和4.39%,其中前者增幅显著;根际真菌群落Chao1丰富度指数降低29.60%,而Shannon多样性指数略有增加,增加5.96%;在门水平上,秸秆还田和不还田处理的水稻根际土壤优势细菌门均为变形菌门、放线菌门、绿弯菌门和酸杆菌门,优势真菌门均为子囊菌门、接合菌门和担子菌门;在属水平上,秸秆还田处理的硝化螺旋菌属和芽胞杆菌属相对丰度分别比不还田处理的显著增加96.11%和106.19%;在水稻孕穗期秸秆还田土壤中水稻纹枯病菌含量比不还田处理的显著增加120.20%;秸秆还田后水稻纹枯病发生加重,病情指数比不还田处理的增加18.10%~45.41%。 相似文献
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Haihua Wang Jinyu Wang Xixu Peng Pinglan Zhou Ningning Bai Jiao Meng Xiaobo Deng 《European journal of plant pathology / European Foundation for Plant Pathology》2014,140(3):515-525
The control efficacy of Platycladus orientalis extract against Rhizoctonia sonali Kühn, the causal agent of rice sheath blight, was evaluated by pot experiments under greenhouse conditions, and the antifungal compounds were isolated and identified through antifungal bioassay-guided fractionation using R. sonali as a tested fungus. The results indicate that the extracts from P. orientalis exhibited a significant reduction in the severity of rice sheath blight. The petroleum ether fraction partitioned from the ethanolic crude extract, showing the highest antifungal activity, was further separated, and two diterpenoid compounds with antifungal property, totarol and sclareol, were isolated and identified from the active subfractions. Totarol and sclareol possessed antifungal activity against most of the tested fungal pathogens of cereal crops such as R. solani, R. cerealis and Fusarium graminearum, indicating a similar broad antifungal spectrum. These findings suggest that the P. orientalis extract and its derived active compounds may be promising candidate agents for controlling plant fungal diseases like rice sheath blight. 相似文献