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1.
Durability of resistance against fungal, bacterial and viral pathogens; present situation 总被引：8，自引：0，他引：8
Jan E. Parlevliet 《Euphytica》2002,124(2):147-156
In evolutionary sense no resistance lasts forever. The durability of a resistance can be seen as a quantitative trait; resistances
may range from not durable at all (ephemeral, or transient) to highly durable. Ephemeral resistance occurs against fungi and
bacteria with a narrow host range, specialists. It is characterised by a hypersensitive reaction (HR), major gene inheritance and many resistance genes, which often occur
in multiple allelic series and/or complex loci. These resistance genes (alleles) interact in a gene-for-gene way with a virulence
genes (alleles) in the pathogen to give an incompatible reaction. The pathogen neutralises the effect of the resistance gene
by a loss mutation in the corresponding avirulence allele. The incompatible reaction is not elicited any more and the pathogenicity
is restored. The pathogens can afford the loss of many avirulences without loss of fitness. Durable resistance against specialised
fungi and bacteria is often quantitative and based upon the additive effects of some to several genes, the resulting resistance
being of another nature than the hypersensitive reaction. This quantitative resistance is present to nearly all pathogens
at low to fair levels in most commercial cultivars. Durable resistance of a monogenic nature occurs too and is usually of
a non-HR type. Resistance against fungi and bacteria with a wide host range, generalists, is usually quantitative and durable. Resistances against viruses are often fairly durable, even if these are based on monogenic,
race-specific, HR resistances. The level of specialisation does not seem to be associated with the durability of resistance.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
2.
Summary Horizontal, uniform, race-non-specific or stable resistance can be discerned according to Van der Plank, from vertical, differential, race-specific or unstable resistance by a test in which a number of host genotypes (cultivars or clones) are tested against a number of pathogen genetypes traces of isolatest. If the total non-environmental variance in levels of resistance is due to main effects only differences between cultivars and differences between isolates) the resistance and the pathogen many (in the broad sense) are horizontal in nature. Vertical resistance and pathogenicity are characterized by the interaction between host and pathogen showing up as a variance compenent in this test due to interaction between cultivars and isolates.A host and pathogen model was made in which resistance and pathogenicity are governed by live polygenic loci. Within the host the resistance genes show additivity. Two models were investigated in model I resistance and pathogenicity genes operate in an additive way as envisaged by Van der Plank in his horizontal resistance. Model II is characterized by a gene-for-gene action between the polygenes of the host and those of the pathogen.The cultivar isolate test in model I showed only main effect variance. Surprisingly, the variance in model II was also largely due to main effects. The contribution of the interaction to the variance uppeared so small, that it would be difficult to discern it from a normal error variance.So-called horizontal resistance can therefore be explained by a polygenic resistance, where the individual genes are vertical and operating on a gene-for-gene basis with virulence genes in the pathogen. The data reported so far support the idea that model II rather than model I is the realistic one.The two models also revealed that populations with a polygenic resistance based on the gene-for-gene action have an increased level of resistance compared with the addition model, while its stability as far as mutability of the pathogen is concerned, is higher compared to those with an additive gene action. Mathematical studies of Mode too support the gene-for-gene concept.The operation of all resistance and virulence genes in a natural population is therefore seen as one integrated system. All genes for true resistance in the host population, whether they are major or minor genes are considered to interact in a gene-for-gene way with virulence genes either major or minor, in the pathogen population.The models revealed other important aspects. Populations with a polygenic resistance based on a gene-for-gene action have an increased level of resistance compared to populations following the addition model. The stability, as far as mutability of the pathogen is concerned, is higher in the interaction model than in the addition model.The effect of a resistance gene on the level of resistance of the population consists of its effect on a single plant times its gene frequency in the population. Due to the adaptive forces in both the host and the pathogen population and the gene-for-gene nature of the gene action an equilibrium develops that allows all resistance genes to remain effective although their corresponding virulence genes are present. The frequencies of the resistance and virulence genes are such that the effective frequencies of resistance genes tend to be negatively related to the magnitude of the gene effect. This explains why major genes often occur at low frequencies, while minor genes appear to be frequent. It is in this way that the host and the pathogen, both as extremely variable and vigorous populations, can co-exist.Horizontal and vertical resistance as meant by Van der Plank therefore do not represent different kinds of resistances, they represent merely polygenic and oligogenic resistances resp. In both situations the individual host genes interact specifically with virulence genes in the pathogen. Van der Plank's test for horizontal resistance appears to be a simple and sound way to test for polygenic inheritance of resistance.The practical considerations have been discussed. The agro-ecosystems should be made as diverse as possible. Multilines, polygenic resistance, tolerance, gene deployment and other measures should be employed, if possible in combination. 相似文献
3.
洛阳市番茄灰霉病菌对嘧霉胺的抗药性检测 总被引：2，自引：2，他引：0
为了明确洛阳市番茄灰霉病菌对苯胺基嘧啶类杀菌剂嘧霉胺的抗药性状况,2012—2013年从洛阳市不同保护地中采集番茄灰霉病病果或病叶,经单孢分离共获得番茄灰霉病菌54株。采用菌丝生长速率法测定了其对嘧霉胺的敏感性。结果显示,高抗菌株9株（16.67%）,中抗菌株19株（35.19%）,低抗菌株10株（18.52%）,敏感菌株16株（29.63%）。比较抗性水平不同菌株间的菌丝生长情况,发现菌丝生长速度和抗性水平无相关性。研究表明,洛阳市番茄灰霉病菌已对嘧霉胺产生不同水平的抗药性,且以中抗菌株为主,生产上应合理更换或轮换使用与嘧霉胺无交互抗性的药剂防治番茄灰霉病。 相似文献
4.
我国主要储粮害虫抗性调查研究 总被引：26，自引：4，他引：26
通过对全国范围内23个省、市和自治区的55个地区粮库中的主要储粮害虫进行取样，用FAO抗性测定方法对92个虫样进行磷化氢抗性测定，得出无抗性虫样占调查虫样总数的54．3％、低抗性虫样占9．8％、中等抗性虫样占7．6％、高抗性虫样占13．0％、极高抗性虫样占15．2％。在调查的几种主要储粮害虫中，高抗性虫样主要为锈赤扁谷盗、谷蠹和米象，其中锈赤扁谷盗的抗性普遍比较严重，谷蠹和米象通过与1995年抗性调查所取的样品进行比较，在最近的8年内米象的抗性倍数增加了10．7％、谷蠹增加了71．2％。磷化氢抗性较高的区域主要是我国西南、华中和华南地区。 相似文献
5.
解磷细菌对7种常见抗生素的抗性研究 总被引：1，自引：1，他引：0
摘要：测定8株供试菌株对氨苄青霉素,四环素,链霉素,卡那霉素,利福平,头孢霉素,氯霉素的不同浓度的抗性反应。结果发现抗氨苄青霉素的菌株有PSB3,PSB4,PSB13,PSB26,PSB58,PSB67,PSB77;抗链霉素的菌株PSB4,PSB13,PSB26,抗卡那霉素的菌株PSB4,PSB26,PSB67,PSB77;PSB4,PSB26,PSB77菌株对四环素具有较强的抗性;PSB4,PSB13,PSB15,PSB26,PSB67,PSB77菌株对氯霉素具有较强的抗性;PSB3,PSB4,PSB26,PSB58,PSB77菌株对利福平有抗性,PSB77菌株对头孢霉素有较强抗性。解磷细菌对抗生素的抗性实验结果,可用于研究今后8株解磷细菌在土壤中的定殖状态。 相似文献
6.
Resistance of 59 barley cultivars to three distinct isolates of Bipolaris sorokiniana, causing brown leaf spot was tested on seedlings and adult plants in a screen house and in a growth room, by determination of disease incidence, disease severity, and rate of lesion expansion. The disease reaction and severity at the seedling stage differed among cultivars. The cultivars MNS Brite, NDB 112, Kindred, Parkland, and Oderbrucke were moderately resistant to brown leaf spot, but the resistance was partial to all three isolates. None genotype with complete resistance was found. The cultivars CI 9539, Svanhals, and Chevron, considered as sources of resistance, were classified as moderately susceptible, and susceptible, respectively. Disease severity, disease reaction, and incidence of B. sorokiniana in grains also differed among the cultivars at the adult plant stage. Nevertheless, none of the genotypes was resistant to B. sorokiniana. The rate of lesion expansion differed among cultivars BR 2, MN 698, Kitchin, Svanhals, and NDB 112, with NDB 112 having the slowest expansion rate (0.194–0.205 mm2/day). 相似文献
7.
外源物质处理对辣椒幼苗抗冷性的影响 总被引：2，自引：1，他引：1
以辣椒幼苗为试验材料,分别喷施不同浓度亚精胺、壳聚糖、水杨酸、CaCl2、甜菜碱溶液,采用昼温/夜温为10℃/5℃低温胁迫5天后进行相对电导率、冷害指数、可溶性糖含量、脯氨酸含量、丙二醛(MDA)含量等指标的测定和分析,探讨外源物质对低温胁迫下辣椒幼苗的影响及作用效果。结果表明,适宜浓度的外源物质可以显著降低辣椒幼苗低温胁迫后的相对电导率、冷害指数和MDA的积累量,提高可溶性糖、脯氨酸等渗透调节物质的含量,对提高辣椒幼苗抗冷性有积极作用。亚精胺、壳聚糖、水杨酸、CaCl2、甜菜碱提高辣椒幼苗抗冷性的最佳诱导浓度分别为0.5 mmol/L、50 mg/L、2 mmol/L、10 mmol/L、10 mmol/L。 相似文献
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以3种豆科藤本植物（厚果鸡血藤、喙果鸡血藤、常春油麻藤）为试验材料,采取PEG6000溶液对其根系进行渗透处理,探讨3种藤本植物的抗旱特性,以期为3种藤本植物今后的相关研究及应用提供理论依据。结果表明：随着PEG6000的浓度增大,3种藤本植物叶片细胞膜透性、可溶性总糖含量、MDA含量呈现不同程度的增加,叶绿素含量呈现下降趋势。3种藤本植物抗旱性强弱为：常春油麻藤＞喙果鸡血藤＞厚果鸡血藤。 相似文献
10.
菲油果自然越冬条件下的生理指标变化的研究 总被引：1，自引：1，他引：0
为了探讨菲油果的抗寒特性,以引种的Coolidge和Mammoth 2个菲油果新品种成熟叶为试验材料,在自然越冬低温环境条件下,对不同低温条件下叶片电导率、可溶性糖、游离脯氨酸(Pro)、超氧化物歧化酶(SOD)、过氧化物酶(POD)、丙二醛(MDA)等几个生理指标的变化情况进行研究。结果表明：在一定的温度范围内,不同品种的菲油果叶片的电导率均随着温度的降低而增大;可溶性糖含量和游离脯氨酸(Pro)随着温度的降低而增加。自然越冬过程中不同品种的菲油果的游离脯氨酸(Pro)呈有规律的变化;细胞内的保护酶(SOD、POD)都表现为随着温度的降低,其活性增强。方差分析结果显示,不同品种的菲油果相对电导率、丙二醛(MDA)、游离脯氨酸(Pro)、过氧化物酶(POD)差异达到显著水平,不同温度间电导率、可溶性糖、丙二醛(MDA)、游离脯氨酸(Pro)、过氧化物酶(POD)、超氧化物歧化酶(SOD)差异达到极显著水平;不同品种间的超氧化物歧化酶(SOD)差异不显著。 相似文献
11.
种植密度对苦荞麦抗倒伏特性及产量的影响 总被引：5，自引：2，他引：3
为了明确苦荞麦抗倒伏特性和适宜的种植密度,提高产量,以‘西荞1号’苦荞麦为材料,研究了不同种植密度对苦荞麦抗倒伏特性及产量的影响。结果表明：种植密度大小显著影响茎秆和根系形态,随着种植密度的增大,田间透光率降低,株高和节间长度增加,主根长、一级侧根数和根体积减少,倒伏率增加,产量呈先升高后降低的变化趋势。相关分析发现,苦荞麦茎秆和根系的特征与植株的抗倒伏特性密切相关。株高和节间长度与茎秆强度呈显著的负相关关系,与倒伏率则呈显著的正相关关系。适宜的种植密度（9×105~12×105株/hm2）能够减少荞麦倒伏的发生,提高抗倒能力,增加群体产量,值得推广应用。 相似文献
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Components of resistance to the pea rust (Uromyces pisi) were studied at the histological level in seedlings of seven pea (Pisum spp.) accessions showing partial resistance under field conditions. Resistance was characterized macroscopically by an increased latent period and a decreased infection frequency in spite of a compatible interaction (high infection type). Histological investigations revealed little differences among accessions in spore germination and appressoria formation, differences being more evident once the stomata were penetrated by the infection structures. Resistance was mainly due to a restriction of haustorium formation with significant levels of early aborted colonies in accessions IFPI3260, PI347321 and PI347347. Furthermore, a reduction in the number of haustoria per colony, hyphal tips per colony and smaller colony size were found in all genotypes studied. Resistance was not associated with early‐ or late‐acting hypersensitivity in any of the genotypes studied. 相似文献
14.
小麦春化脱春化、抗寒处理后POD活性变化的研究 总被引：1，自引：0，他引：1
对6个不同的小麦品种分别进行春化、脱春化和低温处理后,通过测定其体内氧化物酶(POD)的变化,研究分析不同品种小麦抗寒性的变化。结果表明：在不同的处理条件下其POD活性都是先升高,达到峰值后又开始下降;而不同小麦品种在不同处理条件下上升出现峰值的时间不同;不同小麦品种酶活性的变化趋势也有着明显的差异：春化处理‘矮抗58’、‘百麦196’以及‘周麦22’均在春化处理第10天时POD出现了活性最强;而‘周麦18’、‘百农207’以及‘百农69’均在处理20天时POD出现活性最强;脱春化处理POD活性峰值均出现在20天。但是其活性提高程度比春化处理更为明显;而‘百麦196’与‘周麦18’都在处理10天时出现峰值,‘百农207’与‘矮抗58’在处理20天时出现峰值,而‘周麦22’呈下降趋势,‘百农69’在处理30天时出现峰值,效果不明显。说明POD保护酶与抗寒性关系密切,且多数品种经一定时间的春化其抗寒性明显提高。 相似文献
15.
Consequences of classical and biotechnological resistance breeding for food toxicology and allergenicity 总被引：1，自引：0，他引：1
The first food products derived from transgenic plants that are resistant to diseases, insects or viruses are now reaching the market and there is growing public concern about problems of allergenicity and toxicological changes in such transgenic food plants. We review the modifications being carried out or envisaged in molecular resistance breeding and specifically consider the allergenic and toxicological potential of the gene products used. Several protein families that contribute to the defence mechanisms of food plants have members which are allergens or putative allergens and some of these proteins are used in molecular approaches to increase resistance. These include α-amylase and trypsin inhibitors, lectins and pathogenesis-related proteins. An assessment procedure to avoid the transfer of such allergens is described. The source of the transgene is of great importance for the application of immunological assays. In addition to putative changes in the allergenic potential, the toxicological implications of classical and molecular resistance breeding are discussed. Several ‘self defence’ substances made by plants are highly toxic for mammals, including humans. Examples of molecular approaches that could be of toxicological concern are given. The source of the transgene is of no relevance in assessing the toxicological aspects of foods from transgenic plants. Food safety can also be severely influenced by invading pathogens and their metabolic products. This may result in a trade-off situation between ‘nature's pesticides’ produced by transgenic plants or varieties from traditional breeding programmes, synthetic pesticides and mycotoxins or other poisonous products of pests. 相似文献
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Summary Resistance to parasites can be distinguished into true resistance and pseudo or escape resistance. In the former resistance mechanisms operate after intimate contact between the host tissue and the parasite has been established. The resistance is expressed by a reduced growth of the parasite in or on the host tissue. Escape resistances operate before the parasite has made contact with the host tissue and is expressed by a reduced chance of such contacts. True resistance genes are assumed to act in a gene-for-gene way with virulence genes in the parasite. Genes governing escape resistances are supposed to function independently from genes in the parasite (no gene-for-gene action). It is deduced, that escape resistances and polygenic true resistances both are of a horizontal nature. Vertical resistance is to be found in the category of monogenic true resistances. 相似文献
18.
Quantitative resistance to downy mildew (Plasmopara halstedii) in sunflower (Helianthus annuus) 总被引：1，自引：1，他引：0
Downy mildew of sunflower, caused by the Oomycete, Plasmopara halstedii is at present controlled by major resistance genes. However, the pathogen has shown a considerable capacity for changes in
virulence and these resistance genes are overcome only a few years after they have been introduced into new sunflower varieties.
This paper presents research for quantitative, non-race-specific resistance independent of major genes. The reaction of cultivated
sunflower genotypes to field attack by downy mildew was studied over 4 years in several environments and in the presence of
the two most common races in France: 703 and 710. An experimental protocol with pre-emergence irrigation was developed, making
it possible to observe downy mildew reaction whatever the weather conditions. Significant levels of partial resistance were
observed in about 50 inbred sunflower lines among the 800 observed. These results suggest that it should be possible to select
for non-race-specific downy mildew resistance and to include it in modern varieties. However, since this non-specific resistance
is partial, it may be necessary to combine it with major gene resistance. Possible strategies are discussed to obtain durable
resistance to downy mildew. 相似文献
19.
马铃薯Y病毒siRNA介导抗病基因工程研究进展 总被引：1，自引：1，他引：0
马铃薯病毒病是危害马铃薯生产的重要因素,尤其马铃薯Y病毒(Potato virus Y,PVY)严重影响马铃薯产量和品质,为防治带来很大困难。近年来,通过基因工程技术培育抗病毒转基因植株为抵抗PVY侵染提供有效途径。简述了目前PVY病毒siRNA介导抗病基因工程的主要方法策略,包括PVY不同功能基因介导的病毒抗性差异、影响PVY抗病毒基因工程效率的主要因素以及PVY不同株系联合抗病基因工程研究概况,分析了这些方法存在问题及发展趋势,旨在为更好地控制PVY危害提供借鉴。 相似文献