小麦条锈病罹病叶片核酸水解酶活力的变化     

张慧  商鸿生  李振岐 《西北农林科技大学学报(自然科学版)》1995,23(2):24-27

小麦初生叶接种条锈菌后，亲和反应寄主叶片ＲＮａｓｅ活性，分别在潜育期和产孢期呈双峰型增长；不亲和反应叶片ＲＮａｓｅ活性在侵染初期高于健康对照，但低于亲和性反应，其后随着病程发展，近免疫反应叶片ＲＮａｓｅ活性与对照相同，而中度抗病反应叶片也呈双峰增长，峰高及峰延续时间不同于亲和性反应。条锈菌侵染对ＤＮａｓｅ活性影响较小，亲和反应叶片仅在产孢阶段ＤＮａｓｅ活性有所增强，中度抗病反应叶片在显症时活性增强。  相似文献   

小麦/小麦秆锈菌亲和性互作的组织病理学及超微结构研究   总被引：2，自引：0，他引：2  

徐建强  曹远银  侯颖  李会娜 《沈阳农业大学学报》2005,36(5):536-540

利用化学显微技术和生物电镜技术，系统地研究了小麦秆锈菌在感病寄主上发育过程的组织学及超微结构特征。结果表明：小麦秆锈菌的发育过程可分为几个明显的阶段：孢子萌发和芽管形成，附着胞的形成和气孔下囊的分化，初生侵染菌丝和次生侵染菌丝的形成和生长，吸器母细胞和吸器的形成，夏孢子床和夏孢子堆的产生。小麦秆锈菌菌丝沿着细胞壁生长和蔓延．菌丝顶端细胞原生质稠密，代谢旺盛；吸器母细胞形成在细胞壁周围，吸器产生在细胞里面，呈指状，吸器外同和细胞膜区域有吸器外问质的存在。小麦秆锈菌发育早期，小麦细胞一直保持正常；而在发育后期，小麦细胞发生了质壁分离，叶绿体片层受到破坏。  相似文献   

Derivation and testing of a model to predict selection for fungicide resistance     

P. H. F. Hobbelen  N. D. Paveley  B. A. Fraaije  J. A. Lucas  F. van den Bosch 《Plant pathology》2011,60(2):304-313

A mathematical model was derived to predict selection for fungicide resistance in foliar pathogens of cereal crops. The model was tested against independent data from four field experiments quantifying selection for the G143A mutation conferring resistance to a quinone outside inhibitor (QoI) fungicide in powdery mildew (Blumeria graminis f.sp. hordei) on spring barley (Hordeum vulgare). Fungicide treatments with azoxystrobin differed in the total applied dose and spray number. For each treatment, we calculated the observed selection ratio as the ratio of the frequency of the resistant strain after the last and before the first spray. The model accurately predicted the variation in observed selection ratios with total applied fungicide dose and number of sprays for three of the four experiments. Underprediction of selection ratios in one experiment was attributed to the particularly late epidemic onset in that experiment. When the equation representing epidemic development was modified to account for the late epidemic, predicted and observed selection ratios at that site were in close agreement. On a scatter plot of observed selection ratios on predicted selection ratios, for all four experiments, the 1:1 line explained 89–92% of the variance in the mean of observed selection ratios. To our knowledge, this is the first fungicide resistance model for plant pathogens to be rigorously tested against field data. The model can be used with some degree of confidence, to identify anti‐resistance treatment strategies which are likely to be effective and would justify the resources required for experimental testing.  相似文献   

Two class III chitin synthases specifically localized in appressoria and haustoria of Puccinia graminis f. sp. tritici     

Katja Broeker  Sabine Fehser  Klaus B. Tenberge  Bruno M. Moerschbacher 《Physiological and Molecular Plant Pathology》2011,76(1):27-33

Rust fungi like Puccinia graminis f. sp. tritici are known to change their cell wall properties upon entering the plant tissue. Immunohistochemistry revealed the cellular localization of two class III chitin synthase isoforms in rust mycelia developing on and in the host plant. Isoform IIIa is restricted to fungal infection structures growing on the surface of the plant, such as germ tubes and, predominantly, appressoria. Isoform IIIb is found exclusively in haustoria developed inside the plant. Thus, the rust fungus uses at least two chitin synthase isoforms with specialized functions in the differentiation of infection structures during the biotrophic plant-pathogen-interaction.  相似文献   

小麦秆锈菌新型小种Ug99的研究进展     

王曦  陈万权  刘太国  向文胜 《中国植保导刊》2011,31(5)

Ug99(TTKS)为1999年在乌干达首次发现的秆锈菌新小种,对小麦抗秆锈病基因Sr31具有强毒力.此小种致病性极强,传播迅速,给全球小麦生产带来威胁.在肯尼亚用Ug99对我国118个小麦生产品种和材料进行抗病性鉴定结果表明,高感品种占98.3%.该小种一旦传入我国,将对小麦生产造成严重损失.笔者对国内外关于小麦抗Ug99遗传研究、抗病基因分子标记研究现状及我国应对措施进行了概述.  相似文献   

普通小麦-柔软滨麦草易位系M97抗条锈基因的遗传分析和分子作图   总被引：1，自引：1，他引：0  

徐皖彬  尹军良  马东方  唐明双  杨悦  井金学 《植物保护学报》2012,39(1):24-30

为了明确M97抗条锈性遗传规律,在苗期用7个小麦条锈菌系对M97与感病品种铭贤169的杂交后代F1、F2、F3和BC1代进行抗条锈性遗传分析,并对M97抗Sun11-4的抗条锈基因进行SSR分子标记。M97对Sun11-4和Sun11-11的抗病性均由1对显性基因控制,对CY29、CY30、CY33的抗病性由1显1隐2对基因共同控制,对CY31的抗病性由2对显性基因独立或重叠作用控制。以接种Sun11-4的F2代分离群体构建作图群体,筛选到Xwmc222、Xwmc147、Xbarc229和Xwmc339等4个与抗病基因连锁的SSR标记,其遗传距离分别为3.4、4.8、7.6和12.1 cM。将该抗病基因定位于小麦1DS染色体,且该基因不同于已知的抗条锈基因,暂命名为YrM97。用YrM97两侧遗传距离最近的2个标记Xwmc222和Xwmc147对42个黄淮麦区主栽小麦品种进行分子检测,仅有9.5%的品种具有与YrM97相同的标记位点。  相似文献   

向日葵品种对锈病抗性的组织学和超微结构研究     

景岚  王丽芳  康俊  韩青梅  康振生 《中国油料作物学报》2013,35(3)

为了进一步了解向日葵与向日葵锈病病菌的互作关系及品种的抗性机制,采用电子显微镜技术对向日葵品种对锈病抗性的组织学和超微结构进行研究.在电镜下观察发现,向日葵锈病菌侵染向日葵后,在感病品种和抗病品种上发育的组织学和超微结构特征有明显差异.病菌在感病品种细胞间隙分布有大量的胞间菌丝,寄主细胞发生质壁分离;叶绿体变形,叶绿体的片层结构排列零乱,直至叶绿体解体.在抗病品种上表现为菌丝生长受抑,没有观察到吸器的产生,寄主细胞的早期坏死与锈菌的发育受阻密切相关.品种的抗病性可能与饥饿阻止真菌生长有关.  相似文献   

小麦条锈菌夏孢子保存时间及存活力评价     

乔佳兴  马丽杰  孔新宇  王军娟  胡小平 《麦类作物学报》2013,33(5):1043-1047

为在RNA水平上快速检测小麦条锈菌夏孢子的存活力和致病性,选取-20℃下保存1年和10年的菌株,检测小麦条锈菌夏孢子RNA产量和完整性,并通过室内人工接种实验鉴定其致病性。结果表明,RNA产量高于600 ng·mg^-1的夏孢子具有致病性,低于600 ng·mg^-1的夏孢子均已丧失致病性;RNA完整性好的菌株,其存活力高,潜育期和致病性与新鲜夏孢子基本一致,RNA完整性差的菌株存活力低,潜育期延长,致病性弱;RNA严重降解的菌株存活率极低或失活,完全丧失致病性。因此,通过检测小麦条锈菌夏孢子RNA的产量和完整性可以评估其存活力和致病性。  相似文献   

Novel complementary genes for adult plant leaf rust resistance in a wheat stock carrying the 1BL-1RS translocation   总被引：2，自引：0，他引：2  

R. N. Sawhney  J. B. Sharma 《Plant Breeding》1999,118(3):269-271

The wheat-rye translocation (IBL-IRS) that carries the tightly linked genes Lr26/Sr31/Yr9, has been widely exploited in the development of wheat cultivars worldwide. This resistance, however, has become ineffective owing to the evolution of new pathotypes of Puccinia recondita that neutralize the resistance of Lr26. Inheritance studies on ‘Federation4′/‘Kavkaz’ revealed complementary genes derived separately from ‘Federation’ and ‘Kavkaz’ for adult plant resistance. This previously undescribed source of resistance appears to be widely effective and could therefore be used to broaden the genetic base for resistance in India. Its effectiveness in other geographical areas is unknown.  相似文献   

Resistance to powdery mildew in a doubled haploid barley population and its association with marker loci   总被引：2，自引：0，他引：2  

I. Falak  D.E. Falk  N.A. Tinker  D.E. Mather 《Euphytica》1999,107(3):185-192

The genetic basis of resistance to powdery mildew (Erysiphe graminis DC. f.sp. hordei Marchal) was analyzed using doubled haploid barley (Hordeum vulgare L.) lines from the cross Harrington/TR306. Based on infection types observed after inoculation with defined single-conidium isolates, the lines were classified into four groups. The observed phenotypic ratio fit a two-locus model. The two putative loci were mapped relative to molecular markers. One coincided with the previously mapped dMlg locus on chromosome 4. Based on the observed infection types, Harrington carries the Mlg resistance allele, and TR306 carries a second locus on chromosome 7 (5H); this was tentatively designated Ml(TR). It is the first reported race-specific powdery mildew resistance gene located on that chromosome. These two loci were also detected by simple interval mapping of disease severity data from naturally infected field plots. Composite interval mapping with the first two resistance loci as co-factors detected an additional locus on chromosome 6, with a minor effect on resistance. Finally, superimposing the race-specific classification onto the field data provided evidence for a minor-effect locus on chromosome 7 (5H). The Mlg locus had the largest effect, the Ml(TR) locus had an intermediate effect and the other two loci had very small effects. This study demonstrates the effectiveness of an integrated approach to identifying and mapping resistance loci using classification data from inoculated experiments and quantitative data from field experiments. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献