共查询到20条相似文献，搜索用时 171 毫秒
1.
通过罩笼接虫和自然开放式状态下试验，对不同播期的玉米粗缩病病情进行了比较，明确了玉米敏感叶龄为可见叶9叶以下，展开叶为6叶以下，研究证实，将田间灰飞虱转移迁入高峰期与玉米敏感叶龄期错开，可以减轻玉米粗缩病的发病，春玉米播期4月10－15日，夏玉米在6月10－15日，能显著控制玉米粗缩病的危害。 相似文献
2.
3.
玉米播期与玉米粗缩病病株率的关系 总被引：2，自引：0，他引：2
对1976～1979年河北辛集、晋县、正定、永年试验基地玉米不同播期与玉米粗缩病病株率试验数据的统计分析和经 1996～1999年 4年试验数据检验表明 ,4月10日以前播种的早春玉米玉米粗缩病发病株率低 ;5月份播种的晚春玉米和麦套玉米发病株率最高 ;6月份播种的夏玉米发病株率最低。玉米不同播期与玉米粗缩病病株率的关系式为Y=-673.5 -0.0439X2+11.5X。该关系式适用于传毒介体灰飞虱的常规发生和大发生年预测病情 ,符合率达80%～100%。但该关系式在灰飞虱极轻发生年不适用 ,符合率仅为20%。 相似文献
4.
玉米病毒病有粗缩病、矮化叶病和黑条矮缩病,粗缩病和黑条矮缩病是由灰飞虱以持久性方式传播,矮化叶病是由蚜虫以非持久性方式传播。近年来,随着生态条件、耕作制度和栽培体系的不断改变,该病蔓延快、发病广、危害重,给玉米生产造成了很大的威胁。 相似文献
5.
6.
玉米粗缩病是一种危害极大的病毒性病害。在玉米出苗后即可染病，到5-6片叶时才显现症状。其主要症状是病株浓绿，叶片短厚，心叶扭曲卷缩，节间短粗，植株矮化，早发病株多不抽穗、不结实或籽粒极少。一般减产20%-30%，重的地块减产50%以上，甚至绝产。玉米粗缩病主要由灰飞虱传播，土壤和种子不传播。因此，搞好玉米粗缩病的防治，成为确保玉米丰产丰收的重要措施，而防治灰飞虱，消灭传毒媒介则是控制玉米粗缩病流行的关键。 相似文献
7.
8.
玉米粗缩病(MRDV)是由灰飞虱传播的病毒病害。商河县自1994年以来，每年均有程度不同的发生为害。如1996年全县播种玉米3.6万hm2，全部发病。其中春玉米0.1万hm2，90％以上毁种，未毁种的几近绝产；麦田套种玉米2.0万hm2，病株率一般为15％～20％，严重的地块病株率30％以上；直播玉米1.5万hm2，一般病田病株率在5％～10％，严重地块病株率15％～20％。现已发展成为玉米生产上的一种主要的病害。 1 影响发病的因素 1)毒源量。多种禾本科作物和杂草是玉米粗缩病的寄主植物。在生产中，杂草多，管理粗放的玉米田比管理精细、杂草少… 相似文献
9.
10.
11.
对河北省26个主推玉米品种进行抗玉米粗缩病性鉴定,并对其发病率及病情指数与产量损失率的相关性进行了研究。结果表明:河北省目前玉米生产上主推品种中没有免疫和抗病品种,但感病后品种之间的病情严重度有显著差异,病情指数分布在35.37～80.05,产量损失率为15.55%～74.01%。以邢抗2号、费玉2号、费玉4号、沈玉17和农大108的病情严重度较轻,病情指数低于40,表现为感病,其他品种病情指数都在40以上表现为高感。产量损失率与病株率和病情指数呈显著相关,且产量损失率与病情指数的相关性(R=0.982)比产量损失率与病株率的相关性(R=0.756)更强。 相似文献
12.
玉米大斑病菌人工接种方法研究 总被引：2，自引：0，他引：2
The efficient and accurate method of inoculating Exserohilum turcicum on maize is most important for studying the corn leaf blight. In this study, four approaches including spore suspension spraying, inoculation with grinding infected maize leaves, inoculation liquid inoculum into the leaf whorl and inoculation with inoculated sorghum seeds were compared with natural induction in fields during different growth stages of maize in the greenhouse and field. The results showed that disease incidence of all varieties tested were up to 100% by inoculating with inoculated sorghum seeds during the booting stage (11 to 12 leaf stages). This method will not only guarantee the enough pathogen inocula but also be easy to use, and could be an effective way for disease resistance identification in field and greenhouse. 相似文献
13.
在河北省春播玉米WN2000和山东省夏播普通玉米上发现一种叶斑病,其病斑圆形或椭圆形,中心灰白色,边缘褐色,有黄褐色褪绿圈,糯玉米WN2000病斑较大,(3~10)mm×(3~5)mm;普通玉米病斑较小,(1~2)mm×(2~3)mm。通过病原菌分离培养、致病性测定、形态特征观察及r DNA-ITS和1,3,8-三羟基萘还原酶基因(3HNR)序列分析,证明两种大小病斑是由同一种病原菌—麦根腐平脐蠕孢(Bipolaris sorokiniana)引起。田间调查结果表明,在山东省夏播玉米各品种苗期叶片上均有不同程度的发病,发病率最高的为冠玉6号,病株率52%,最低的为五岳88,病株率2%;鲜食玉米仅在河北春播玉米WN2000上发生,发病率为32%。麦根腐平脐蠕孢侵染不同玉米品种产生两种大小不同的病斑在国内外尚属首次报道。 相似文献
14.
玉米致死性坏死病是由玉米褪绿斑驳病毒(Maize chlorotic mottle virus,MCMV)和一种或多种马铃薯Y病毒科病毒复合侵染引起的。2014年1月在对云南省玉溪市玉米病毒病害的调查中发现了一些表现严重花叶、矮化叶片甚至整个植株坏死症状的玉米。对采集样品进行RT-PCR检测,所有样品中都同时检测到了MCMV和甘蔗花叶病毒(Sugarcane mosaic virus,SCMV),在一个样品中同时检测到了MCMV、SCMV和南方水稻黑条矮缩病毒(Southern rice black-streaked dwarf virus)。 相似文献
15.
Fei Wang Guozheng Qin Zhenhua Sui Zhaohui Wang Zhaoyu Wang Jialin Yu Juren Zhang 《European journal of plant pathology / European Foundation for Plant Pathology》2006,116(4):289-300
The study of maize rough dwarf disease (MRDD) and breeding for resistance requires inoculation of maize plants by means of planthoppers. The plant age, insect density and inoculation duration are main factors in the success of maize rough dwarf disease inoculation. These parameters were tested using a susceptible maize inbred line Ye478. Using one or two-leaf plants, 15 planthoppers per plant and a five day inoculation duration, the line Ye478 was the most susceptible with 100% diseased plants; F112132 was moderately susceptible with 60% diseased plants and 90110 and F022411 were resistant without any disease. The results were consistent with those from six years of field studies. Using enzyme-linked immunosorbent assay (ELISA) and real-time quantitative RT-PCR, rice black-streaked dwarf virus was detected in severely diseased plants. The plants were rated from 0 to 3 according to their symptoms at the time of flowering. Plants scoring 0, 1 and 2 could not be distinguished by ELISA, only by real-time quantitative RT-PCR. All of the plants with a score of 3 were positive by ELISA and real-time quantitative RT-PCR. The significant differences in the average viral contents in plants with different symptom ratings could be distinguished by using real-time RT-PCR. 相似文献
16.
永安地区发病辣椒植株表现小叶、黄化、丛枝、簇芽等症状。利用植原体16SrDNA基因的通用引物R16mF2/R16mR2和R16F2n/R16R2,对发病辣椒植株总DNA进行巢式PCR检测,获得约1.2kb的特异性DNA片段。经测序并在GenBank数据库进行比对分析,共获得4条植原体特定的16SrDNA基因序列(CHY-C4-1、CHYY1-1、CHY-Y7-1、CHY-G1-1)。将测得的4条序列与已报道的植原体序列进行同源性比对,并构建系统进化树,结果显示获得的4条植原体序列均聚类到16SrI组,其中CHY-Y1-1、CHY-Y7-1、CHY-G1-1与16SrI-B亚组植原体聚类到同一支,而CHY-C4-1与已报道的16SrI组内的6个亚组均未聚类到一支,因此建议将CHY-C4-1命名为新的亚组。利用iPhyClassifier在线分析软件对获得的4条植原体序列进行虚拟RFLP分析,结果与进化树获得的结果一致。 相似文献
17.
18.
When the influence of host species, inoculum density, temperature, leaf wetness duration, and leaf position on the incidence
of gentian brown leaf spot caused by Mycochaetophora gentianae, was examined, the fungus severely infected all seven Gentiana triflora cultivars, but failed to infect two cultivars of G. scabra and an interspecific hybrid cultivar. Inoculum density correlated closely with disease incidence, and a minimum of 102 conidia/mL was enough to cause infection. In an analysis of variance, temperature and leaf wetness duration had a significant
effect upon disease incidence, which increased with higher temperature (15–25°C) and longer duration of leaf wetness (36–72 h).
No disease developed at temperatures lower than 10°C or when leaf wetness lasted <24 h. At 48-h leaf wetness, disease incidence
was 0, 28, 77, and 85% at 10, 15, 20, and 25°C, respectively. Middle and lower leaves on the plant were more susceptible than
upper leaves. In microscopic observations of inoculated leaves, >50% of conidia germinated at temperatures >15°C after 24-h
leaf wetness. More appressoria formed at higher temperatures (15–25°C) with extended duration of leaf wetness (24–72 h). At
48-h leaf wetness, appressorium formation was 0, 8, 26, and 73% at 10, 15, 20, and 25°C, respectively. These results suggest
that temperature and leaf wetness duration were important factors for infection of gentian leaves. 相似文献
19.
20.
Grey leaf spot of maize, (Zea maydis L.) (Cercospora zeae-maydis) Tehon and Daniels, is one of the most destructive leaf diseases of maize. The distribution and severity of grey leaf spot has increased over the past 10 to 15 years. The United States and South Africa are main areas where research on the disease has been concentrated. The research results have provided valuable and significant insight into pathogen epidemiology and allowed an integrated management system to be developed. However, management options are a result of the agricultural system under which maize is produced. The pathogen survives only on maize, so crop rotation and stubble management are major factors in disease management, but resistant hybrids offer the best option for economic control. Many other factors, such as soil fertility, plant density, irrigation and chemical control, can significantly influence a grey leaf spot epidemic, although a single management practice will not control the pathogen effectively. 相似文献