Molecular characterization of Erwinia amylovora strains from different host plants through RFLP analysis and sequencing of hrpN and dspA/E genes     

S. Giorgi  M. Scortichini† 《Plant pathology》2005,54(6):789-798

A total of 73 Erwinia amylovora strains obtained from 13 Maloideae host species and from Rubus spp., and isolated from different geographic areas, were assessed using RFLP and DNA sequencing analysis of the 3' hrp N gene and/or of a fragment of 1341 bp of the dsp A/E region. An Erwinia pyrifoliae strain, used as outgroup, was checked in the same way. For the three strains isolated from Rubus spp. and for one strain from Amelanchier sp., RFLP analysis of the hrp N gene using the Rsa I enzyme yielded a PCR product 60 bp smaller than that of all the other strains. Sequence analysis of the gene revealed this was due to the absence of a 60 bp fragment in the noncoding region downstream of the gene. The strain PD 2915, isolated from Amelanchier sp. grown in Canada, showed five same-sense substitutions and one missense substitution at position 868 of the hrp N gene, converting aspartic acid into asparagine. Also, restriction analysis of a fragment of 613 bp of the dsp A/E region with Cfo I revealed an RFLP pattern suitable for differentiating the E. amylovora strains isolated from Rubus spp. and Amelanchier sp. from all the others. In the dsp A/E coding region, the four strains showed 13–14 missense point mutations, in some cases yielding drastic amino acid substitutions. In addition, partial sequencing of the dsp A/E region of PD 2915 from Amelanchier sp. indicated a higher similarity to E. amylovora strains isolated from Rubus spp. than towards strains from other Maloideae hosts. The E. pyrifoliae strain showed 23 single nucleotide substitutions along the hrp N gene and 88% of nucleotide identity with E. amylovora strains in the portion of dsp A/E region. Artificial inoculations on immature pear fruits and young shoots of Maloideae and Ruboideae showed a restricted pathogenicity for the strains from Rubus and Amelanchier , with the latter inciting blight symptoms only on Amelanchier .  相似文献   

<Emphasis Type="Italic">Dittrichia viscosa</Emphasis> and<Emphasis Type="Italic">Rubus ulmifolius</Emphasis> as reservoirs of aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae) and the role of certain Coccinellid species     

Nickolas?G.?KavallieratosEmail author  George?J.?Stathas  Christos?G.?Athanassiou  George?Th.?Papadoulis 《Phytoparasitica》2002,30(3):231-242

The role of the self-sown shrubsDittrichia viscosa (L.) W. Greuter andRubus ulmifolius Schott as reservoirs of aphid parasitoids was investigated. In the field studies conducted,D. viscosa grew adjacent to crops of durum wheat and barley andR. ulmifolius grew adjacent to cotton. The relative abundance of the parasitoids of(a) Capitophorus inulae (Passerini) onD. viscosa, (b) Rhopalosiphum padi (Linnaeus) on durum wheat and barley,(c) Aphis ruborum (Börner) onR. ulmifolius, and(d) Aphis gossypii Glover on cotton in various parts of Greece, was assessed during the years 1996–2000. In 2000, the fluctuation of parasitization of the above four aphid species was recorded and the action of the aphidophagous predators of the family Coccinellidae was studied. It was observed thatAphidius matricariae Haliday predominated onC. inulae andR. padi in all sampling cases. In contrast,Lysiphlebus fabarum (Marshall) was the dominant species parasitizingA. ruborum onR. ulmifolius andA. gossypii on cotton in Thessaly (central Greece) and Macedonia (northern Greece), whereasLysiphlebus confusus Tremblay et Eady andBinodoxys acalephae (Marshall) were the dominant parasitoid species in Thrace (northern Greece).Coccinella septempunctata Linnaeus was the most abundant coccinellid species on durum wheat, whereasAdonia variegata (Goeze) predominated on cotton. However, coccinellid individuals were scarce on bothD. viscosa andR. ulmifolius. The present study indicated that these two shrubs can be regarded as useful reservoirs of aphid parasitoids.  相似文献   

粉枝莓的组织培养与植株再生   总被引：1，自引：0，他引：1  

罗建 《林业科技》2003,28(1):46-48

利用粉枝莓的茎段和幼嫩叶片作为外植体，研究了不同激素水平对诱导产生愈伤组织、芽和根及完成植株再生的影响。试验结果表明：MS 6-BA0.5 NAA0.2培养基对诱导愈伤组织和芽的分化效果最佳，1/2MS IBA0.3对促进生根效果较好，在两步移栽法中，移栽存活率分别为94％和98％。  相似文献   

粉枝莓的组织培养与植株再生研究   总被引：2，自引：0，他引：2  

罗建 《四川林勘设计》2003,(1):1-4

利用粉枝莓的茎段和幼嫩叶片作为外植体，研究了不同激素水平对诱导产生愈伤组织，芽和根，完成植株再生的影响。试验结果表明：MS 6-BA0.5 NAA0.2培养基对诱导愈伤组织和芽的分化效果最佳。1/2MS IBA0.3对促进生根效果较好，在两步移栽法中，移栽存活率分别为94%和98%。  相似文献   

树莓主要农艺性状与小区有效产量的相关和通径分析     

苏泽春  和加卫  李兆光  杨燕林  杨正松  和秀云 《江西农业学报》2014,(12)

以8份树莓品种为试验材料,对农艺性状和小区有效产量进行相关性分析、回归分析和通径分析。结果表明,各农艺性状与单株产量的相关程度依次为:平均果重>侧根数>多年基生枝长度>侧根粗>主根粗>结果枝数>多年基生枝粗度>平均每枝结果数>平均单株基生枝数>平均单株产量;多元回归方程为:y=1.29+1.63x3-1.02x4-2.35x6-2.63x7+2.31x8+2.15x10。通径分析表明:侧根数、平均果重和平均单株产量对小区有效产量有直接的正向作用,主根粗、多年基生枝长度和平均单株基生枝数对小区有效产量的直接的负向作用。主根粗、多年基生枝长度和平均单株基生枝数可以通过协调其它性状对小区有效产量发挥作用。  相似文献   

Further evidence on the effects of gene H,which confers cane hairyness,on resistance to raspberry diseases     

D. L. Jennings 《Euphytica》1982,31(3):953-956

Summary Gene H determines cane hairyness in raspberries and was reported to facilitate escape from infection by Botrytis cinerea and Didymella applanata. However, experiments with mycelial inoculations of wounded canes showed that it conferred a form of resistance which was evident for a long period after the establishment of infections by these pathogens. The gene also contributed to the resistance of fruit to B. cinerea and of canes to Leptosphaeria coniothyrium. Alternative hypotheses to explain these observations are discussed: two based upon its possible genetic linkage with a gene or genes for resistance and one based upon its possible pleiotropic effects.  相似文献   

Resistance to cane spot (Elsinoë veneta) in the red raspberry and its relationship to resistance to yellow rust (Phragmidium rubi-idaei)     

D. L. Jennings  G. R. McGregor 《Euphytica》1988,37(2):173-180

Summary Varying degrees of resistance to cane spot were recorded among red raspberries in two cultivar trials and in 15 segregating families. The inheritance of resistance was studied, and the effect of gene H which determines the presence of cane hairs was assessed in eight of the families. The 0 to 5 scale used to record disease incidence was found to approximate to a logarithmic scale for the range of 0 to 93 cane spots per cane. Gene H and h phenotypes averaged scores of 3.05 and 2.42 respectively, but other genes independent of these had more influence on resistance. The latter genes appeared to be largely dominant. The possibility is discussed that one of them was a major gene with a large effect, but the evidence was equivocal in the absence of discontinuity in the expression of resistance. Resistance to yellow rust was studied in five of the families and was highly correlated with resistance to cane spot. Gene H had more influence on this disease, the mean counts of telia per unit leaf area for H and h segregates being 17.1 and 4.1 respectively.  相似文献   

渗透胁迫对树莓离体叶片可溶性物质及相对含水量的影响   总被引：1，自引：0，他引：1  

王霞  董玉芝  王梅  盛芳  马桂丽 《新疆农业大学学报》2002,25(2):14-17

树莓(Rubus idaeus L．)离体叶片在聚乙二醇(PEG)渗透胁迫条件下，相对含水量降低，可溶性糖含量先增加而后降低，脯氨酸含量持续增加，增加程度品种问存在差异。-2．0MPa和-2．2MPa两个处理的4个品种的树莓，相对含水量都有所下降，并且随着处理时问的延长，叶片相对含水量下降越剧烈，降低程度种间存在差异。同品种树莓用-2．2MPa渗透液处理时可溶性糖含量稍高于-2．0MPa处理的，而-2．2MPa渗透液处理的脯氨酸含量大大高于-2．0MPa处理的。  相似文献   

Spotted wing drosophila infestation of California strawberries and raspberries: economic analysis of potential revenue losses and control costs     

Goodhue RE  Bolda M  Farnsworth D  Williams JC  Zalom FG 《Pest management science》2011,67(11):1396-1402

BACKGROUND: Economic costs of spotted wing drosophila (SWD) include yield and associated revenue losses, labor and material costs for monitoring and management and revenue losses due to the closure of export markets should fruit from SWD‐infested regions be banned by trading partners. This analysis focuses on two types of loss in the California raspberry and strawberry industries: yield losses in the absence of management, and insecticide material costs on a per treatment basis. It computes the cost of a specific management program for raspberries in California's Central Coast region. RESULTS: Insecticide material and application costs per treatment and the cost of the management program are small relative to the yield losses in the absence of management that are observed by growers, researchers and others in initial infestations. CONCLUSION: It is difficult to evaluate precisely the share of pest management program costs due to SWD because insecticides are sometimes used to manage multiple pests, and because labor‐intensive field sanitation efforts to control SWD are recommended practices already. Given these considerations, this analysis finds that the benefits to SWD management well outweigh the costs examined here. Evaluating the efficacy of managing SWD is essential in assessing the risks that SWD poses and the benefits of pest management programs. Copyright © 2011 Society of Chemical Industry  相似文献   

豫南山区野生悬钩子资源开发利用研究     

张琰  朱庆松 《河南林业科技》2003,23(4):13-14

豫南山区丰富的野生悬钩子植物资源,具有较高的利用价值,通过良种选择,资源培育,综合开发利用,为野生资源的合理开发提供了重要的途径。  相似文献