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2007-2009年,在甘肃天水对不同生态条件及海拔高度的小麦白粉病菌进行了闭囊壳形成率观察、模拟病圃试验及越夏调查,结果表明: 小麦白粉病菌有性时期最早在扬花期开始出现,不同抗性类型品种、不同生态条件下出现的迟早和形成量的多少有较大差异。小麦白粉病菌主要以分生孢子在天水市不同海拔高度的自生麦苗上越夏,是当地秋苗发病的初侵染源。二阴山区高海拔地区病叶率高于川道及低海拔地区。闭囊壳在正常年份只侵染自生麦苗,在整个侵染循环中仅起着间接作用。 相似文献
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北京地区小麦白粉菌闭囊壳越夏的研究 总被引：3，自引：0，他引：3
由于世界各地气候条件、地理环境的不同,小麦白粉菌闭囊壳的越夏情况差异很大。在夏季干燥无雨炎热的地区,闭囊壳能顺利越夏,成为小麦白粉病在秋苗上的初侵染源;在夏季多雨潮湿的地区,闭囊壳则不能越夏,关键在于是否导致自生麦苗发病,北京地区小麦白粉菌闭囊壳的越夏行为尚未见报道,作者进行了这方面的研究。 相似文献
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北京地区小麦白粉病初侵染源的研究 总被引：2，自引：0，他引：2
各种自然条件下闭囊壳越夏试验结果表明:土壤中,地面和麦茬上,麦垛顶层和底层,室外自然条件下的闭囊壳在秋苗出土前相继变成空壳;室内自然条件下,种子中以及麦垛中层的闭囊壳在越夏季节期间,子囊原生质体结构发生畸变,失去形成子囊孢子的能力。上述各种环境中的闭囊壳先后于7月中旬至9月上旬失去生活力和传病能力,均不能越夏后成为小麦白粉病的初侵染源。在小麦播种时用做过上述各种处理的闭囊壳进行隔离接种试验,试验结果进一步证实了越夏试验结论的正确性。在房山区白粉病发生严重的张坊及十渡一带山区,通过对自生麦苗和小麦秋苗感染白粉病情况的野外调查发现:海拔140m以上山区自生麦苗上的分生孢子是北京地区小麦白粉病在秋苗上的主要侵染源之一。 相似文献
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2015—2017年,选择平凉市崆峒区不同生态条件的白庙乡贾洼村、寨河乡闫湾村、香莲乡香莲村、草峰镇盘龙村半屲、草峰镇陈洼村、四十路铺镇及大寨乡白土村等地7个调查点,对小麦白粉病病菌进行了越夏期有性世代作用调查。结果表明,小麦白粉病病菌主要以分生孢子在自生麦苗上越夏,是当地秋苗发病的初侵染源。南部山地病叶率高于泾河川道区和北部塬区。小麦白粉病病菌有性时期最早在草峰镇盘龙村半屲的小麦抽穗期开始出现,不同生态条件下出现的迟早有差异。闭囊壳在正常年份只侵染自生麦苗,在整个侵染循环中仅起着间接作用。 相似文献
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1979—1985年在四川省阿坝州越夏区进行条锈病发生规律调查。该地区海拔2900米以上的晚熟小麦约2.5万亩,条锈病持续发生至9月下旬,为自生麦苗和部分早播秋苗提供菌源。自生麦苗的发病面积近3万亩,其中休闲地约2.5万亩,主要分布在松潘、黑水2400—2900米地区,自生麦苗较多,发病较重;荞麦复种地约4000亩,主要分布在黑水、茂汶和汶川等地1700—2500米地带,自生麦苗较少,发病较轻。自生麦苗提供菌源的关键时期是9月上旬至10月下旬。秋苗发病面积约3.7万亩,主要分布在松潘、黑水2700—2950米地带,自9月中旬至12月下旬不断发生流行,而以8月中旬至9月中旬播种的秋苗发病较重,菌源较多,这在越夏菌源传播中起着很重要的作用。条锈菌在阿坝州又可越冬,构成周年侵染循环,常年流行,这不仅严重危害当地小麦生产,而且向广大冬麦区秋苗提供大量菌源。因此,综合治理阿坝州越夏区至关重要。 相似文献
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东北春麦区小麦白粉菌的侵染循环 总被引：9，自引：1，他引：9
小麦白粉菌(Blumeria graminis DC.Speer)可以在我国东北的南部冬麦区以菌丝垫形态潜伏在小麦苗基部叶片和叶鞘上越冬,以混在干燥保存的小麦种子中的闭囊壳越夏。自生麦苗和白粉病的野生寄主在侵染循环中不起作用。小麦白粉菌的毒力频率(Vf)分析表明,公主岭、沈阳、海城、大连和烟台的小麦白粉菌同属于一个群体。东北春麦区小麦白粉病初发日期和高空天气图分析表明,东北春麦区小麦白粉病的初侵染菌源来自胶东半岛冬麦区。在一定的天气系统控制下,小麦白粉菌的分生孢子随夏初的偏南气流,在700毫巴高度层向北传播,进入东北春麦区。随降雨沉降,并侵染小麦植株。 相似文献
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1.小麦白粉病的流行区有三种类型:(1)以分生孢子继代越夏为主要型式的终年流行区;(2)以闭囊壳休眠越夏、子囊孢子主要侵染秋苗的秋苗带菌越冬流行区;(3)以闭囊壳越夏、越冬,子囊孢子在春季侵染的春季侵染流行区。2.白粉病的发病程度,主要决定于春季的流行速度,影响流行速度的因素是:(1)大面积种植感病品种、品种抗性的退化和病菌新生理小种的出现,是病害大流行的基础;(2)气候是影响年度间病情轻重的主导因素。10℃以上天气出现早,21℃以上高温出现迟,则发病期长、病情重。过程性降雨有利病菌孢子的繁殖与侵入。病情与气候的关系有:多雨限制 相似文献
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研究表明,粉锈宁拌种,适期播种和翻耕灭茬是控制阿坝州越夏区秋季小麦条锈菌源的有效措施。拌种处理早播冬麦约占播种面积的20—30％,便可压低整个越夏区秋苗菌源数量,控制翌年条锈病流行。粉锈宁拌种防治秋苗条锈病效果达99％,推迟暴发期5—7天,最终控制效果为68%,比不拌种对照区增产10.9％,亩增小麦24公斤,经济效益为1∶11。同时拌种还可兼治小麦白秆病、黑穗病和白粉病等当地重要病害。适期播种可显著减少秋苗发病。翻耕两次可有效地消灭自生麦苗及其菌源。文中对通过压低越夏区秋季菌源,保护冬麦区秋苗作用的问题进行了讨论。 相似文献
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Charles V. Eadsforth 《Pest management science》1986,17(3):311-325
Reverse-phase high performance liquid chromatography (h.p.l.c.), using a C18 analytical column, has been applied to the determination of partition coefficients for a range of agrochemicals and industrial chemicals. Using a correlation plot of the logarithm of the capacity factor (k) with the logarithm of the n-octanol/water partition coefficient (Pow), partition coefficients were predicted with a 95% tolerance interval of ± log 0.80 of the literature ‘shake flask’ value for compounds of random structure over the log Pow range 0–6. Individual regression lines were fitted for compounds of comparable size and functional grouping, which reduced any bias and thereby enabled more accurate predictions to be made. The reverse-phase h.p.l.c. method has a number of advantages over the traditional ‘shake-flask’ method. Quantitative methods are not required or do not have to be developed and only the determination of the retention time is necessary. Quick and precise determinations of retention times are facilitated by h.p.l.c. and further improvement can be obtained by automation of solvent mixing, solute injection and data processing. H.p.l.c. was used to generate partition coefficient data for highly hydrophobic materials and, because of its resolving power, data for mixtures and solvent fractions. Dual detection, using u.v. and r.i. in series, was necessary for some compounds, particularly unknown mixtures and impure compounds. Calculations of log Pow based on the fragment-addition method using the structural data file, MACCS, was of considerable value in confirming experimentally derived values. In certain cases, calculated log Pow values were considered more trustworthy than experimental values. 相似文献
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醉蝶白粉病的发生规律与防治 总被引：4，自引：0，他引：4
研究明确醉蝶白粉病菌以闭囊壳、分生孢子和菌丝在病残体上或土壤中越冬。醉蝶开花至盛花期为发生高峰期 ,高温干燥的气候条件发病严重。发生程度与土壤肥力、田间种植密度等关系密切。加强管理 ,清洁田园和30%特富灵、6%乐必耕、75%百菌清、25%粉锈宁可湿性粉剂等在定植后、开花前后喷药 ,每隔10d1次 ,连续5～6次 ,可基本控制该病发生。 相似文献
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ABSTRACT A natural epidemic of Fusarium wilt on coca (Erythroxylum coca) in Peru prompted the suggestion of possibly using the pathogen Fusarium oxysporum f. sp. erythroxyli as a mycoherbicide against this narcotic plant. During field trials conducted in Kauai, HI, to test the pathogenicity of the coca wilt pathogen, ants were observed removing formulations from test plots. While removal of formulations by ants was considered detrimental with respect to conducting field tests, ant removal was considered potentially beneficial in disseminating the mycoherbicide. Thus, research was initiated to assess the ability of formulation additives to alter the preference of ants for the formulated mycoherbicide. In Hawaii, preference of indigenous ants for removing formulations was tested using three different food bases (rice, rice plus canola oil, and wheat flour [gluten]). Similar tests were conducted at Beltsville, MD, using F. oxysporum f. sp. melonis, in which the formulation based on wheat flour was replaced by a formulation based on canola meal. Formulations based on wheat were preferred by ants in both locations; up to 90% of the wheat plus rice flour granules (C-6) and the wheat gluten plus kaolin granules (pesta) were removed within 24 h, while only 20% of those containing rice without oils were taken. However, when either canola, sunflower (Maryland only), or olive oil was added to the rice formulation, up to 90% of the granules were taken. The formulation based on canola meal was less attractive to ants, as only 65% of the granules were removed within a period of 24 h. Ants showed no preference with respect to presence or absence of fungal biomass. To alter the attractiveness of the C-6 formulation to ants, C-6 was amended with three natural products. Canna and tansy leaves were added to C-6 at a ratio of 1:5 (wt/wt), while chili powder was added at 1:25 or 1:2.5 (wt/wt). Canna, tansy, and the higher rate of chili powder significantly reduced the number of C-6 granules removed by ants. Canna and tansy leaves affected neither germination nor sporulation of the mycoherbicide, while the high concentration of chili powder reduced viability of propagules in the formulation. More F. oxysporum f. sp. erythroxyli-type colonies were recovered from inside ant nests (9 cm depth) than from nest surfaces, indicating that ants may distribute the mycoherbicide in the soil profile. Ants passively carried propagules of F. oxysporum f. sp. erythroxyli outside their bodies, as well as either very closely adhering to the outside or within their bodies. 相似文献
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The pathogenic type (form and race) of Fusarium oxysporum, which generates wilt symptoms on tomato, was rapidly identified with a polymerase chain reaction (PCR)-based technique.
We compared the partial nucleotide sequences of endo polygalacturonase (pg1) and exo polygalacturonase (pgx4) genes from isolates of F. oxysporum ff. sp. lycopersici (FOL) and radicis-lycopersici (FORL) from Japan and designed specific primer sets (uni, sp13, sp23, and sprl) based on the nucleotide differences that appeared
among the pathogenic types. PCR with the uni primer set amplified a 670∼672-bp fragment from all isolates of FOL and FORL. With the sp13 primer set, an amplicon of 445 bp was obtained only from isolates of FOL race 1 and 3. With the sp23 primer set, a 518-bp fragment was obtained from isolates of FOL race 2 and 3. The sprl primer set yielded a 947-bp fragment from isolates of FORL, but not from FOL. A combination of amplifications with these primer sets effectively differentiated the pathogenic types of F. oxysporum in tomato. 相似文献
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Attempts were made to produce somatic hybrids between isolates of Puccinia striiformis f. sp. tritici and f. sp. hordei. A mixed infection was produced on a common susceptible barley host, Fong Tien, using white-spored isolates of P. striiformis f. sp. tritici and yellow-spored isolates off. sp. hordei. Selection was made for non-parental spore colour on selective wheat and barley hosts, and variants thus isolated were analysed for virulence markers, and for isozyme and double-stranded RNA (dsRNA) markers, all of which clearly differentiated the parental isolates. Two white-spored (non-parental) isolates were found on the selective barley host which otherwise resembled the parental f. sp. hordei isolate in virulence, isozyme and dsRNA markers. The most likely explanation of the origin of these isolates is mutation to white spore colour in the f. sp. hordei isolate. 相似文献