共查询到20条相似文献，搜索用时 15 毫秒
1.
Species‐ and population‐specific differences in fungicide resistance and aggressiveness within Botrytis makes basic data on genetic diversity important for understanding disease caused by this fungus. Genetic diversity of Botrytis was surveyed between 2008 and 2012 from grapes from five New Zealand wine‐growing regions. A total of 1226 isolates were gathered from symptomless flower buds at the start of the growing season and 1331 isolates from diseased fruit at harvest. Two species were found, B. cinerea and B. pseudocinerea. Botrytis pseudocinerea was common in both Auckland vineyards sampled, and infrequent elsewhere. However, even in Auckland, it was rarely isolated from diseased fruit. The presence of the Boty and Flipper transposons was assessed. Isolates with all four transposon states (Boty only, Flipper only, both Boty and Flipper, no transposons) were found for both species. Both vineyards in the Auckland region had high numbers of Flipper‐only isolates at flowering; both vineyards from the Waipara region had high numbers of Boty‐only isolates at flowering. Most isolates from diseased fruit at harvest contained both transposons. These observations suggest that B. pseudocinerea, and isolates with one or both of the transposons missing, may be less aggressive than B. cinerea, or than isolates with both transposons present. Two clades were resolved within B. pseudocinerea, only one of which has been reported from European vineyards. Phylogenetic diversity within B. cinerea in New Zealand was similar to that known from Europe, including isolates that appear to match Botrytis ‘Group S’. The taxonomic implications of this genetic diversity are discussed. 相似文献
2.
Late blight caused by Phytophthora infestans is one of the most devastating diseases of the potato crop. Resistance breeding and current fungicides are unable to control the rapidly evolving P. infestans and new control strategies are urgently needed. This study examined mechanisms of dl ‐β‐aminobutyric acid (BABA)‐induced resistance (IR) in the potato–P. infestans system. Leaves from two cultivars that differ in their degree of resistance, Bintje and Ovatio, were analysed after foliar treatment with BABA. Rapid activation of various defence responses and a significant reduction in P. infestans growth were observed in leaves treated with BABA. In the more resistant cultivar, Ovatio, the activation was both faster and stronger than in Bintje. Microscopic analysis of leaves treated with BABA revealed induction of small hypersensitive response (HR)‐like lesions surrounded by callose, as well as production of hydrogen peroxide (H2O2). Molecular and chemical analyses revealed soluble phenols such as arbutin and chlorogenic acid and activation of PR‐1. These results show a direct activation of defence responses in potato, rather than priming as reported for other plant species. They also show that the efficiency of BABA‐IR differs between cultivars, which highlights the importance of taking all aspects into consideration when establishing new methods for disease management. 相似文献
3.
A preinoculative soil drench application of 0·5 mm β‐aminobutyric acid (BABA) significantly inhibited colonization of oilseed rape (Brassica napus, susceptible cultivar Falcon) by Verticillium longisporum and also prevented plant stunting caused by the pathogen. To better understand the defence responses induced by BABA, the presence of occlusions in the plant hypocotyl, levels of salicylic acid (SA) and hydrogen peroxide (H2O2), phenylalanine ammonia lyase (PAL) activity and expression of PR‐1 and PDF1.2 genes were examined. Transverse sections through the hypocotyl region of BABA‐treated plants showed clear vessels surrounded by phenol‐storing cells, in contrast to numerous obstructed vessels in water‐treated plants, in response to the pathogen. A significant increase in SA levels was observed in the hypocotyls of both water‐ and BABA‐treated plants in response to the pathogen; however, SA levels were unrelated to disease resistance. The level of H2O2 decreased in both treatments in response to the pathogen. A significant increase in PAL activity was observed in hypocotyl tissues of BABA‐treated plants. The expression patterns of PR‐1 and PDF1.2 were similar in the two treatments in response to the pathogen, indicating no involvement of these genes in resistance. The results indicate a similar organ specificity of the plant hypocotyl for chemically induced internal resistance as for genotype‐related resistance, two phenomena which, however, are based on contrasting cytological responses in the vascular tissues. Nonetheless, evidence is provided that the activity of the phenylpropanoid pathway plays a crucial role in both types of resistance. 相似文献
4.
5.
6.
7.
N. Okon Levy Y. Meller Harel Z. M. Haile Y. Elad E. Rav‐David E. Jurkevitch J. Katan 《Plant pathology》2015,64(2):365-374
The effect of soil solarization and Trichoderma harzianum on induced resistance to grey mould (Botrytis cinerea) and powdery mildew (Podosphaera xanthii) was studied. Plants were grown in soils pretreated by solarization, T. harzianum T39 amendment or both, and then their leaves were inoculated with the pathogens. There was a significant reduction in grey mould in cucumber, strawberry, bean and tomato, and of powdery mildew in cucumber, with a stronger reduction when treatments were combined. Bacillus, pseudomonad and actinobacterial communities in the strawberry rhizosphere were affected by the treatments, as revealed by denaturing gradient gel electrophoresis fingerprinting. In tomato, treatments affected the expression of salicylic acid (SA)‐, ethylene (ET)‐ and jasmonic acid (JA)‐responsive genes. With both soil treatments, genes related to SA and ET – PR1a, GluB, CHI9 and Erf1 – were downregulated whereas the JA marker PI2 was upregulated. Following soil treatments and B. cinerea infection, SA‐, ET‐, and JA‐related genes were globally upregulated, except for the LOX genes which were downregulated. Upregulation of the PR genes PR1a, GluB and CHI9 in plants grown in solarized soil revealed a priming effect of this treatment on these genes' expression. The present study demonstrates the capacity of solarization and T. harzianum to systemically induce resistance to foliar diseases in various plants. This may be due to either a direct effect on the plant or an indirect one, via stimulation of beneficial microorganisms in the rhizosphere. 相似文献
8.
9.
In Arabidopsis, abscisic acid (ABA) application can induce resistance by priming for callose deposition; this resistance is impaired in ABA-deficient and -insensitive mutants. In tomato, ABA-deficiency causes resistance to Botrytis cinerea. Here, we show that callose deposition after B. cinerea inoculation is weaker in the ABA-deficient sitiens tomato mutant compared to the wild type (WT). Inhibition of callose synthesis did not affect resistance in sitiens, but caused additional susceptibility in WT. These findings indicate that callose deposition is not part of sitiens defence responses that are effective in blocking B. cinerea and suggest that callose deposition only contributes to WT basal resistance. Furthermore, also in tomato callose formation is at least in part ABA-dependent. However, it seems that in contrast to Arabidopsis, basal ABA levels in tomato are sufficiently high to prime for callose deposition. 相似文献
10.
F. P. Olivieri M. C. Lobato E. González Altamiranda G. R. Daleo M. Huarte M. G. Guevara A. B. Andreu 《European journal of plant pathology / European Foundation for Plant Pathology》2009,123(1):47-56
Since most plants possess resistance mechanisms which can be induced upon pre-treatment with a variety of chemical compounds,
the use of β-aminobutyric acid (BABA) as a defence inducer without reported toxic effect on the environment was studied. The
aim of this work was to analyse the effectiveness of BABA to induce resistance against Phytophthora infestans and Fusarium solani in potato cultivars differing in their level of resistance to late blight. The behaviour of some components of biochemical
mechanisms by which BABA increases resistance against P. infestans, as well as the effect of BABA on the activity of a potential pathogenic factor of F. solani, were studied. Plants with four applications of BABA throughout the crop cycle produced tubers more resistant to P. infestans and F. solani than non-treated plants. In addition, tuber slices from treated plants, inoculated with P. infestans, showed an increase in phenol and phytoalexin content. The aspartyl protease StAP1 accumulation was also higher in tubers obtained from treated plants and inoculated with P. infestans. This result was observed only in the more resistant potato cv. Pampeana, early after infection. In the potato–F. solani interaction, infected tubers coming from BABA-treated plants showed minor fungal proteolytic activity than infected, non-treated
ones. For potato cvs Pampeana and Bintje, the BABA treatment improved the yield of harvested tubers. The number of tubers
per plant and total weight of harvested tubers was greater for those obtained from treated plants with two early or four applications
of BABA. The results show that the BABA treatment increases the resistance of potatoes but the degree of increase depends
on the original level of resistance present in each cultivar. 相似文献
11.
Magnesium oxide nanoparticles induce systemic resistance in tomato against bacterial wilt disease 
下载免费PDF全文
下载免费PDF全文 Bacterial wilt is a serious problem affecting many important food crops. Recent studies have indicated that treatment with biotic or abiotic stress factors may increase the resistance of plants to bacterial infection. This study investigated the effects of magnesium oxide nanoparticles (MgO NP) on disease resistance in tomato plants against Ralstonia solanacearum, as well as its antibacterial activity. The roots of tomato seedlings were inoculated with R. solanacearum and then immediately treated with MgO NP; the treated plants showed very little inhibition of bacterial wilt. In contrast, when roots were drenched with a MgO NP suspension prior to inoculation with the pathogen, the incidence of disease was significantly reduced. Rapid generation of reactive oxygen species such as O2?˙ radicals was observed in tomato roots treated with MgO NP. Further O2?˙ was rapidly generated when tomato plant extracts or polyphenols were added to the MgO NP suspension, suggesting that the generation of O2?˙ in tomato roots might be due to a reaction between MgO NP and polyphenols present in the roots. Salicylic acid‐inducible PR1, jasmonic acid‐inducible LoxA, ethylene‐inducible Osm, and systemic resistance‐related GluA were up‐regulated in both the roots and hypocotyls of tomato plants after treatment of the plant roots with MgO NP. Histochemical analyses showed that β‐1,3‐glucanase and tyloses accumulated in the xylem and apoplast of pith tissues of the hypocotyls after MgO NP treatment. These results indicate that MgO NP induces systemic resistance in tomato plants against R. solanacearum. 相似文献
12.
BACKGROUND: Bombus terrestris L. bumblebees are widely used as commercial pollinators, but they might also be of help in the battle against economically important crop diseases. This alternative control strategy is referred to as pollinator‐and‐vector technology. The present study was designed to investigate the capacity of B. terrestris to fulfil this role in greenhouse strawberry flowers, which were manually inoculated with a major plant pathogen, the grey mould Botrytis cinerea Pers.: Fr. A model microbiological control agent (MCA) product Prestop‐Mix was loaded in a newly developed two‐way bumblebee dispenser, and, in addition, the use of the diluent Maizena‐Plus (corn starch) was tested. RESULTS: Importantly, loading of the MCA caused no adverse effects on bumblebee workers, with no loss of survival or impairment of flight activity of the workers during the 4 week flowering period. Secondly, vectoring of Prestop‐Mix by bumblebees resulted in a higher crop production, as 71% of the flowers developed into healthy red strawberries at picking (preharvest yield) as compared with 54% in the controls. In addition, these strawberries were better protected, as 79% of the picked berries remained free of B. cinerea after a 2 day incubation (post‐harvest yield), while this percentage was only 43% in the control. Overall, the total yield (preharvest × post‐harvest) was 2–2.5 times higher than the total yield in the controls (24%) in plants exposed to bumblebees vectoring Prestop‐Mix. Thirdly, the addition of the diluent Maizena‐Plus to Prestop‐Mix at 1:1 (w/w) resulted in a similar yield to that of Prestop‐Mix used alone, and in no negative effects on the bumblebees, flowers and berries. CONCLUSIONS: This greenhouse study provides strong evidence that B. terrestris bumblebees can vector a MCA to reduce B. cinerea incidence in greenhouse strawberries, resulting in higher yields. Similar yields obtained in the treatments with Prestop‐Mix and Prestop‐Mix + Maizena‐Plus suggest an equally efficient dissemination of the biocontrol agent into the flowers with only half the initial concentration of Prestop‐Mix, which illustrates the importance of the diluent. Copyright © 2011 Society of Chemical Industry 相似文献
13.
14.
M. O. Leyva B. Vicedo I. Finiti V. Flors G. Del Amo M. D. Real P. García‐Agustín C. González‐Bosch 《Plant pathology》2008,57(6):1038-1046
The antifungal activity of hexanoic acid on the phytopathogen Botrytis cinerea was studied. This chemical inhibited both spore germination and mycelial growth in vitro in a concentration‐ and pH‐dependent manner, and stopped spore germination at a very early stage, preventing germ‐tube development. The minimum fungicidal concentration (MFC) for in vitro spore germination was 16 mm . Hexanoic acid also inhibited in vitro mycelial growth of germinated spores at an MFC of 12 mm . Studies performed to characterize the mechanisms underlying the antimicrobial effect of hexanoic acid showed that it alters fungal membrane permeability. In addition, hexanoic acid treatment increased the levels of spermine, spermidine, putrescine and cadaverine in B. cinerea mycelia. Spray application of hexanoic acid at fungicidal concentrations on 4‐week‐old tomato plants prior to fungal inoculation reduced necrosis diameter by approximately 60%. Application of the same hexanoic acid concentrations on previously infected plants reduced further necrosis expansion by around 30%. The results suggest that this chemical acts as a preventive and curative fungicide. Interestingly, treatments with hexanoic acid at concentrations below the MFC in hydroponic solution prior to fungal inoculation significantly reduced necrosis area. These results suggest an inducer effect of plant responses for hexanoic acid treatments at these concentrations. Hexanoic acid is a good candidate for safe antifungal treatments for the control of B. cinerea, which is responsible for many economic losses on fruits, vegetables and flowers. 相似文献
15.
T. Phukan K. Kabyashree N. Singh G. Jha R. V. Sonti S. Genin S. Kumar Ray 《Plant pathology》2017,66(5):835-841
Ralstonia solanacearum is a phytopathogenic bacterium that colonizes the xylem vessels of host plants leading to a lethal wilt disease. Although several studies have investigated the virulence of R. solanacearum on adult host plants, infection studies of this pathogen on the seedling stages of hosts are less common. In a preliminary observation, inoculation of R. solanacearum F1C1 on 6‐ to 7‐day‐old tomato seedlings by a simple leaf‐clip strategy resulted in a lethal pathogenic condition in seedlings that eventually killed these seedlings within a week post‐inoculation. This prompted testing of the effect of this inoculation technique in seedlings from different cultivars of tomato and similar results were obtained. Colonization and spread of the bacteria throughout the infected seedlings was demonstrated using gus‐tagged R. solanacearum F1C1. The same method of inoculating tomato seedlings was used with R. solanacearum GMI1000 and independent mutants of R. solanacearum GMI1000, deficient in the virulence genes hrpB, hrpG, phcA and gspD. Wildtype R. solanacearum GMI1000 was found to be virulent on tomato seedlings, whereas the mutants were found to be non‐virulent. This leaf‐clip technique, for inoculation of tomato seedlings, has the potential to be a valuable approach, saving time, space, labour and costs. 相似文献
16.
17.
Importance of timing and repetition of stubble cultivation for post‐harvest control of Elymus repens 下载免费PDF全文
下载免费PDF全文 Without herbicides, the control of Elymus repens relies on intensive tillage, often in the form of repeated post‐harvest stubble cultivations followed by ploughing. This is costly and time‐consuming and also increases the risk of nitrogen leaching. Our aim was to quantify the controlling effect on E. repens of single and repeated cultivation and differing time of cultivation in relation to spring cereal harvest. A 2‐year experiment was conducted at two sites in the south and east of Sweden in 2011–2012 and 2012–2013. We compared no, single and repeated tine cultivation followed by mouldboard ploughing; the single cultivation was performed directly after harvest or 20 days after harvest; when repeated, the first cultivation was performed immediately or 5 days after harvest, followed by a second cultivation 20 days after harvest. Tine cultivation in combination with mouldboard ploughing resulted in 50–70% lower rhizome biomass, and increased average subsequent cereal yields by 0–130% compared with ploughing alone. Large E. repens populations appeared to be more efficiently reduced by tine cultivation than smaller populations. A single tine cultivation 20 days after harvest tended to result in a higher E. repens shoot density and more rhizome biomass in the subsequent year than tine cultivation directly after harvest. Additional cultivation 20 days after harvest did not improve control of E. repens or the subsequent cereal grain yield, compared with a single cultivation conducted directly after harvest. In conclusion, preventing the growth of E. repens during the early part of the post‐harvest autumn period was more important than starving rhizomes with repeated cultivations. 相似文献
18.
Development of a Pseudomonas syringae–Eutrema salsugineum pathosystem to investigate disease resistance in a stress tolerant extremophile model plant 下载免费PDF全文
下载免费PDF全文 To improve the ability to understand how plants respond to multiple and/or concurrent stresses, disease resistance was investigated in Eutrema salsugineum, an extremophile model plant that is highly tolerant of abiotic stress. Compared to Arabidopsis (Col‐0), both Yukon and Shandong Eutrema accessions exhibit increased resistance to Pseudomonas syringae pv. tomato DC3000 (Pst) and pv. maculicola (Psm), with Shandong Eutrema exhibiting greater resistance to Pst than Yukon Eutrema. RT‐PCR of the EsPR1 (Pathogenesis‐related 1) defence marker gene confirmed RNA‐Seq data that healthy Shandong Eutrema constitutively expresses EsPR1. The data suggests that Shandong Eutrema exists in a highly primed state of defence preparedness, as it displays heightened resistance compared to defence‐primed natural accessions of Arabidopsis (Can‐0, Bur‐0). Pathogen‐triggered PR1 expression was delayed in Yukon Eutrema; however, these plants were resistant to Pst suggesting that Yukon Eutrema employs a PR1‐independent mechanism to resist Pst. This study demonstrates that Eutrema is an excellent model to investigate biotic stress tolerance. The Eutrema–P. syringae pathosystem will facilitate future studies to understand how this extremophile tolerates both abiotic and biotic stress, and will allow exploration of the interplay of these responses to inform efforts to improve stress tolerance in crops. 相似文献
19.
V Kati L Scarabel D Thiery‐Lanfranchi V Kioleoglou S Liberopoulou C Dlye 《Weed Research》2019,59(5):367-376
The issue of cross‐ or multiple resistance to acetolactate synthase (ALS) inhibitors and the auxinic herbicide 2,4‐D was investigated in Papaver rhoeas L., a common and troublesome weed in winter cereals, in a broad‐scale study across four European countries. A combination of herbicide sensitivity bioassays and molecular assays targeting mutations involved in resistance was conducted on 27 populations of P. rhoeas originating from Greece (9), Italy (5), France (10) and Spain (3). Plants resistant to the field rate of 2,4‐D were observed in 25 of the 27 populations assayed, in frequencies ranging from 5% to 85%. Plants resistant to ALS‐inhibiting herbicides (sulfonylureas) were present in 24 of the 27 populations, in frequencies ranging from 4% to 100%. Plants resistant to 2,4‐D co‐occurred with plants resistant to sulfonylureas in 23 populations. In four of these, the probability of presence of plants with cross‐ or multiple resistance to 2,4‐D and sulfonylureas was higher than 0.5. ALS genotyping of plants from the field populations or of their progenies, identified ALS alleles carrying a mutation at codon Pro197 or Trp574 in 2,4‐D‐sensitive and in 2,4‐D‐resistant plants. The latter case confirmed multiple resistance to 2,4‐D and ALS inhibitors at the level of individual plants in all four countries investigated. This study is the first to identify individual plants with multiple resistance in P. rhoeas, an attribute rarely assessed in other weed species, but one with significant implications in designing chemical control strategies. 相似文献
20.
Assessing host specialization of Botrytis cinerea on lettuce and tomato by genotypic and phenotypic characterization 下载免费PDF全文
下载免费PDF全文 This study tested the hypothesis that Botyrtis cinerea shows host specialization on tomato and lettuce, using phenotypic and genotypic tools. Strains were isolated from tomato and lettuce grown together in the same greenhouse. Forty‐four lettuce strains and 42 tomato strains were investigated for their genetic diversity and their aggressiveness. Both gene diversity and allelic richness were significantly higher in lettuce strains than in tomato strains (P = 0·01). Cluster analysis revealed a clear division of the strains under study into two clusters. However, this structure did not separate the strains according to their host of origin. Tomato strains were significantly more aggressive than lettuce strains when inoculated on tomatoes (P = 0·001), but no significant differences in aggressiveness were observed when the strains were inoculated on lettuce (P = 0·17) or on apple (P = 0·87). The results suggest an absence of clear host specialization of B. cinerea on tomato and lettuce. 相似文献