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151.
利用经初选确定的5种具有较好保鲜能力的配方,采用离体叶段滤纸保存法、离体叶段琼脂保存法和试管苗保存法对小麦白粉病菌纯化菌系保存效果进行了研究.结果表明,对小麦幼苗第一叶叶段保鲜效果最好的配方是沈保6号,当使用40~60μg/mL最适浓度时,第25天叶段绿色仍可达到90%以上.保存菌种的最适环境条件研究结果表明,在4℃冰箱中,以离体叶片沈保6号琼脂保存和离体叶沈保6号浸润滤纸保存效果最佳,在第40天叶片绿色仍分别达到78.0%和68.0%,孢子萌发率可达26.7%和26.8%. 相似文献
152.
153.
Seiji TSUGE Ayako FURUTANI Rie FUKUNAKA Yasuyuki KUBO Osamu HORINO 《Journal of General Plant Pathology》2001,67(1):51-57
Xanthomonas oryzae pv. oryzae (X. o. pv. oryzae) T7174 is virulent on rice cultivar IR24 and avirulent on IR-BB2. From recent reports, some virulence and avirulence factors
of plant pathogenic bacteria are transferred to plant cells through the hrp-dependent type III secretion system. In this study, we investigated the involvement of hrp genes in the compatible and the incompatible interactions between rice and X. o. pv. oryzae after co-inoculation with hrpXo mutants derived from T7174 and virulent strains. Growth of the mutants, named 74ΔHrpXo and 76ΔHrpXo, was repressed in IR24 when the mutants were applied alone. However, growth of the mutants was complemented by co-inoculation
with virulent strains. Growth of bioluminescent hrpXo mutant 76ΔHrpXo in IR24 and its growth in IR-BB2 after co-inoculation with T7133, which is virulent on both cultivars, was equally complemented,
as detected by bioluminescence from the mutant. On the other hand, only partial complementation of growth of T7174L76, which
is a bioluminescent and pathogenic derivative of T7174, by T7133 was observed in IR-BB2. Thus, growth of the hrpXo mutant of X. o. pv. oryzae was complemented by virulent strains in both susceptible and resistant rice leaves with the parental strain.
Received 21 July 2000/ Accepted in revised form 26 October 2000 相似文献
154.
B. Samils U. Lagercrantz M. Lascoux U. Gullberg 《European journal of plant pathology / European Foundation for Plant Pathology》2001,107(4):399-409
Amplified fragment length polymorphism (AFLP) was used to study the genetic structure of populations of the willow leaf rust, Melampsora epitea, in Swedish willow plantations. In total, 197 isolates collected from Salix viminalis clones in three locations in Sweden were analysed. AFLP profiles based on 83 markers were used to compute genetic distances between pairs of individuals. High levels of gene and genotypic diversity were detected in all populations, with 96% of the AFLP loci being polymorphic and with normalized Shannon's diversity indices ranging from 0.977 to 1.0. Analysis of molecular variance (AMOVA) showed small significant differences among locations, although most of the molecular variability was found within locations (97.5%). Five isolates from one willow clone in one location differed markedly from the common pattern. When these five exceptional isolates were excluded, no significant differences among willow clones were found with AMOVA. Sexual reproduction and spore migration appear to be important factors for the population genetic structure of this pathogen. 相似文献
155.
156.
157.
作者应用生物间遗传学的观点和方法,对河北省的小麦品种与叶锈菌的相互作用进行了分析。供试的叶锈菌是来自河北省的177个标样,供试的28个小麦品种包括河北省的主要生产品种、区试品种(系)抗源和新鉴别寄主。用毒力频率法分析品种与叶锈菌群体的关系,有6个品种即鉴61、保麦2号、翼植88-5163、石86-2848、唐86-4043和百农3217表现较抗病。根据这6个品种对叶锈菌群体的反应、列出33种不同的毒性公式,在此基础上,根据若干品种对叶锈菌群体同时表现抵抗或感染计算抗性组合,为品种合理布局选择最佳组合,在小种鉴定方面,用新鉴别寄主对177个菌株的反应鉴定出频率在3.4%以上的小种8个,其中以V1,9-16和V1,9-12,14-16的频率较高,分别为13.6%和10.7%,也是近两年来北方冬麦区常出现的小种类型。在小种鉴定的基础上,根据28个品种与6个优势小种互作所出现的浸染型来推导品种和叶锈菌的基因型,共推导出7个抗性基因分散在不同的品种中。 相似文献
158.
苹果砧木M26离体叶片愈伤组织发生及分类研究 总被引:1,自引:0,他引:1
对苹果砧木M26 离体叶片愈伤组织的发生研究表明,取继代后30 ~35 d 的试管苗顶部1~4 叶位的叶片,沿与主脉垂直方向横切后,以叶背面朝上方式置于愈伤组织诱导培养基上,经观察在叶片近柄端切口处愈伤组织发生较早,产生量较多。最适的愈伤组织诱导培养基为:MS+2 ,4 - D0 .2 ~2 .0 mg·l- 1 +IAA0 .2 ~2.0 mg·l- 1 + BA0 .5 ~1.0 mg·l- 1 + 蔗糖3 % + 琼脂0.6% 。将诱导产生的愈伤组织按外部形态、细胞特点及生理生化指标等分为三类,其中表面干燥致密、细胞内含物丰富、淀粉、蛋白质及干物质含量均较高的Ⅲ类愈伤组织的芽再生频率最高,可达83 .33 % ,是能利用的愈伤组织类型。 相似文献
159.
I. Vloutoglou B.D.L. Fitt J.A. Lucas 《European journal of plant pathology / European Foundation for Plant Pathology》1999,105(6):585-595
Controlled environment studies were conducted to determine the effects of inoculum density, temperature, leaf wetness and light regime on the infection of linseed by Alternaria linicola. The % cotyledons and leaves with symptoms, and the disease severity (% leaf area with symptoms) increased linearly when the inoculum density increased from 1×103 to 1×105 conidiaml–1. The first symptoms appeared on cotyledons and leaves 4 and 6 days after inoculation, respectively. Eight hours of leaf wetness were sufficient to initiate the disease at 25°C but not at 15°C, when 10-h periods of leaf wetness were required. % leaf area with symptoms was lower at 15°C than that at 25°C irrespective of the leaf wetness periods tested. Interruption of a continuous leaf wetness period by a 12-h dry period, occurring at any time between 1 and 18h after inoculation, decreased the % cotyledons with symptoms and the disease severity, with the greatest reductions (60% and 100%, respectively) being observed when the dry period began 6h after inoculation. A. linicola conidia were able to exploit successive 12-h periods of leaf wetness cumulatively to infect linseed plants. Disease incidence and severity were positively correlated with the dark period following inoculation, but they were negatively related to the length of the initial light period. Our findings suggest that infection of linseed by A. linicola and further development of symptoms can occur under unfavourable environmental conditions. 相似文献
160.
植物叶面结露时间长短及露量与农作物病虫害,特别是真菌病害的发生有密切的关系。为监测叶露情况我们设计制作了叶露仪。该仪器适合在植物病虫害发生规律的科学研究和大田作物病害预测预报工作中使用。 相似文献