共查询到20条相似文献,搜索用时 31 毫秒
1.
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
2.
Maryline Magnin-Robert Patricia Trotel-Aziz Daniel Quantinet Sylvie Biagianti Aziz Aziz 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(1):43-57
In this study, the biocontrol ability of seven grapevine-associated bacteria, previously reported as efficient against Botrytis cinerea under in vitro conditions, was evaluated in two vineyard orchards with the susceptible cv. Chardonnay during four consecutive
years (2002–2005). It was shown that the severity of disease on grapevine leaves and berries was reduced to different levels,
depending on the bacterial strain and inoculation method. Drenching the plant soil with these bacteria revealed a systemic
resistance to B. cinerea, even without renewal of treatment. Accordingly, this resistance was associated with a stimulation of some plant defense
responses such as chitinase and β-1,3-glucanase activities in both leaves and berries. In leaves, chitinase activity increased
before veraison (end-July) while β-1,3-glucanase reached its maximum activity at ripening (September). Reverse patterns were
observed in berries, with β-1,3-glucanase peaking at full veraison (end-August) and chitinase at a later development stage.
Highest activities were observed with Acinetobacter lwoffii PTA-113 and Pseudomonas fluorescens PTA-CT2 in leaves, and with A. lwoffii PTA-113 and Pantoea agglomerans PTA-AF1 in berries. These results have demonstrated an induced protection of grapevine against B. cinerea by selected bacteria under field conditions, and suggest that induced resistance could be related to a stimulation of plant
defense reactions in a successive manner. 相似文献
3.
Waseem Raza Xingming Yang Hongsheng Wu Yang Wang Yangchun Xu Qirong Shen 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(3):471-483
A bacterial strain was isolated from the rhizosphere of healthy watermelon plants in a heavily wilt-diseased field. This isolate
was tentatively identified as Paenibacillus polymyxa (SQR-21) based on biochemical tests and partial 16S rRNA sequence similarity. The purified antifungal compounds were members
of the fusaricidin group of cyclic depsipeptides having molecular masses of 883, 897, 947, and 961 Da with an unusual 15-guanidino-3-hydroxypentadecanoic
acid moiety, bound to a free amino group. The strain SQR-21 was not able to produce antifungal volatile compounds but was
able to produce cellulase, mannase, pectinase, protease, β-1,3-glucanase and lipase enzymes. However, the strain did not show
any chitinase activity. Biocontrol potential of this strain was evaluated against Fusarium oxysporum cause of Fusarium wilt disease of watermelon in a greenhouse experiment. This strain combined with organic fertiliser decreased
the disease incidence by 70% and increased the dry plant weight by 113% over the control. 相似文献
4.
Dale R. Walters Linda Paterson Cecile Sablou David J. Walsh 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(1):73-82
It has been suggested that if plants in the field are already induced, their ability to further enhance induced resistance
might be compromised. This was examined in barley by inoculating the first two leaves with Rhynchosporium secalis prior to treatment of leaves three and four with an elicitor combination, followed by inoculation with R. secalis. The elicitor combination used consisted of acibenzolar-S-methyl, β-aminobutyric acid, and cis-jasmone, which was shown previously to provide higher levels of disease control in barley than any of the components used
individually. The elicitor combination reduced infection by R. secalis, and led to an up-regulation of PR1-b, a marker gene for systemic acquired resistance, and increased activities of the defence-related enzymes cinnamyl alcohol
dehydrogenase (CAD), peroxidase (POX), and β-1,3-glucanase. It also led to down-regulation of LOX2, a gene involved in biosynthesis of jasmonic acid. In plants where the first two leaves were inoculated with R. secalis prior to treatment of leaves three and four with elicitor, these increased defence responses did not occur, and control of
R. secalis infection on leaves three and four was also reduced. These results suggest that, at least in young barley plants, prior infection
with R. secalis compromises their ability to respond effectively to elicitors. The results might help to explain the relatively poor performance
of induced resistance in the field, particularly in cereals, compared to plants grown under controlled conditions. 相似文献
5.
Mathiyazhagan Kavino Sankarasubramanian Harish Neelakandan Kumar Duraisamy Saravanakumar Ramasamy Samiyappan 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(4):353-362
Pseudomonas fluorescens strains CHA0 and Pf1 were investigated for their biocontrol efficacy against Banana bunchy top virus (BBTV) in banana (Musa spp.) alone and in combination with chitin under glasshouse and field conditions. Bioformulation of P. fluorescens strain CHA0 with chitin was effective in reducing the banana bunchy top disease (BBTD) incidence in banana under glasshouse
and field conditions. In addition to disease control, the bioformulation increased the economic yield significantly compared
to the untreated control. Increased accumulation of oxidative enzymes, peroxidase (PO), polyphenol oxidase (PPO), phenylalanine
ammonia lyase (PAL), pathogenesis-related (PR) proteins, chitinase, β-1,3-glucanase and phenolics were observed in CHA0 bioformulation
amended with chitin-treated plants challenged with BBTV under glasshouse conditions. Indirect ELISA indicated the reduction
in viral antigen concentration in P. fluorescens strain CHA0 with chitin-treated banana plants corresponding to reduced disease ratings. The present study revealed that induction
of defence enzymes by P. fluorescens with chitin amendment reduced the BBTD incidence and increased bunch yield in banana. 相似文献
6.
Nobutaka SOMEYA Masami NAKAJIMA Tadaaki HIBI Isamu YAMAGUCHI Katsumi AKUTSU 《Journal of General Plant Pathology》2002,68(2):177-182
An antagonistic bacterium, Serratia marcescens strain B2, controlled rice blast after being sprayed onto rice phylloplane, as did the bacterial suspension when poured into
rhizosphere soil of rice plants. Three days after root treatment, rice blast conidia were sprayed onto rice foliage. A week
after pathogen inoculation, rice blast was suppressed and lesions caused by the pathogen decreased in size. Brown deposits
were observed around sites of pathogen infection after root treatment. Induced resistance was not associated with an increase
in the activitiy of peroxidase, phenylalanine ammonia lyase, tyrosine ammonia lyase, β-1,3-glucanase, β-1,4-glycosidase, N-acetylhexosaminidase or chitinase. However, lipoxygenase levels were elevated after the root treatment with strain B2 following
inoculation with the pathogen. Strain B2 was not detected in rice foliage after root treatment. These data suggest that strain
B2 induced resistance against rice blast caused by Pyricularia oryzae.
Received 1 November 2001/ Accepted in revised form 25 January 2002 相似文献
7.
Black rot, caused by Xanthomonas campestris pv. campestris, (Xcc), is one of the most serious diseases of crucifers world-wide. Forty-nine genotypes were evaluated for resistance under field
conditions in Tanzania after artificial inoculation with Xcc race 1. Open pollinated white cabbage cultivars were generally susceptible, while Portuguese and pointed cabbages exhibited
partial resistance. Some F1 white cabbage cultivars were highly susceptible, whereas others exhibited a high level of partial
resistance. The most promising of the hybrid cultivars were T-689 F1, Gianty F1, No. 9690 F1, N 66 F1, and SWR-02 F1. Breeding
line Badger I-16 exhibited the highest level of resistance of all genotypes. The genotypes accounted for 72.9–75.5% of the
variation of the disease severity when assessed on the leaves, and 71.4% of the variation when assessed as internal black
rot in heads at harvest. High correlations (equal to or above 0.7) were found between disease severities assessed on leaves
three times during the growing season and also with the amount of internal black rot in heads. Leaf loss also was correlated
with disease severity. The high genetic determination of the trait and the high correlations between disease assessments indicate
that selection for resistance to black rot will be efficient when field screenings are carried out. Evaluation of genotypes
for disease severity on leaves during the growing season combined with evaluations of head resistance in the most promising
genotypes may be a simple method to select resistant cultivars. 相似文献
8.
Khalid Pervaiz Akhtar Muhmmad Yussouf Saleem Muhammad Asghar Mushtaq Ahmad Nighat Sarwar 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(4):435-450
Sixty-nine tomato genotypes representing nine Solanum species were evaluated for resistance to Cucumber mosaic virus (CMV) subgroup IA and its aphid vector Myzus persicae. Resistance was assessed by visual scoring of symptoms in the field under natural conditions, and in the greenhouse by artificial
inoculations through aphid M. persicae and mechanical transmissions in the year 2007 and 2009. Considerable variation in responses was observed among the evaluation
methods used. Field evaluations were found liable to errors as different levels were observed for the same genotypes in the
different years, however mechanical inoculation was found to be the most useful in identifying CMV subgroup IA resistance,
in contrast aphid transmission was most useful in identifying insect transmission resistance. All genotypes observed as highly
resistant to CMV subgroup IA in the field or through vector transmission became systemically infected through mechanical inoculations.
Using mechanical inoculation, six genotypes (TMS-1 of S. lycopersicum, LA1963 and L06049 of S. chilense, LA1353, L06145 and L06223 of S. habrochaites) were found resistant and another six (L06188 and L06238 of S. neorickii, L06219 of S. habrochaites, L05763, L05776 and L06240 of S. pennellii) were found tolerant showing mild symptoms with severity index (SI) ranging 1-2 and with delayed disease development after
a latent period (LP) of 18–30 days. However, these genotypes were found to be resistant to highly resistant in the field and
through inoculation by M. persicae; and they also supported low population levels of M. persicae except TMS-1. Another nine genotypes (LA2184 of S. pimpinellifolium L., LA2727 of S. neorickii, LA0111, L06221, L06127 and L06231 of S. peruvianum L., LA1306, L06057 and L06208 of S. chmielewskii) showing a susceptible response after mechanical inoculation were highly resistant, resistant and tolerant after M. persicae transmission. The resistant genotypes, identified in the present study can be exploited in the breeding programmes aimed
at developing tomato varieties resistant to CMV subgroup IA and broadening the genetic base of CMV-resistant germplasm. The
differences observed between mechanical and aphid transmission suggests that one should consider both evaluation methods for
tomato germplasm screening against CMV subgroup IA. 相似文献
9.
Erika Valéria Saliba Albuquerque Poliene Martins Costa Ana Cristina Meneses Mendes Gomes Marcilene Santos Antonio Alves Pereira Michel Nicole Diana Fernandez Maria Fatima Grossi-de-Sa 《European journal of plant pathology / European Foundation for Plant Pathology》2010,127(3):365-373
Root-knot nematodes (RKN) are obligate parasite species of the genus Meloidogyne that cause great losses in Arabica coffee (Coffea arabica L.) plantations. Identification of resistant genotypes would facilitate the improvement of coffee varieties aiming at an
environmental friendly and costless nematode control. In this work, the C. arabica genotype ‘UFV 408-28’ was found to be resistant to the most destructive RKN species M. incognita. Pathogenicity assays indicated that the highly aggressive populations of M. incognita races 1, 2 and 3 were not able to successfully reproduce on ‘UFV 408-28’ roots and displayed a low gall index (GI = 2). An
average reduction of 87% reduction of the M. incognita population was observed on ‘UFV 408-28’ when compared to the susceptible cultivar ‘IAC 15’. By contrast, ‘UFV 408-28’ was
susceptible to the related species M. exigua and M. paranaensis (GI = 5 and 4, respectively). Histological observations performed on sections of UFV408-28 roots infected with M. incognita race 1 showed that nematode infection could be blocked right after penetration or during migration and establishment stages,
at 6 days, 7 days and 8 days after infection (DAI). Fluorescence and bright field microscopy observations showed that root
cells surrounding the nematodes exhibited HR-like features such as accumulation of phenolic compounds and a necrotic cell
aspect. In the susceptible ‘IAC 15’ roots, 6 DAI, feeding sites contained giant cells with a dense cytoplasm. Necrotic cells
were never observed throughout the entire infection cycle. The HR-like phenotype observed in the ‘UFV 408-28’—M. incognita interaction suggests that the coffee resistance may be mediated by a R-gene based immunity system and may therefore provide new insights for understanding the molecular basis of RKN resistance
in perennial crops. 相似文献
10.
11.
R. Lebecka 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(2):345-348
Solanum nigrum, black nightshade, is a wild non-tuber bearing hexaploid species with a high level of resistance to Phytophthora infestans (Colon et al. 1993), the causal agent of potato late blight, the most devastating disease in potato production. However, the genetic mode of
resistance in S. nigrum is still poorly understood. In the present study, two S. nigrum accessions, 984750019 (N19) and #13, resistant (R) and susceptible (S), respectively, to three different isolates of P. infestans, were sexually crossed. The various kinds of progeny including F1, F2, F3, and backcross populations (BC1; F1 × S), as well as two populations produced by self-pollinating the R parent and S parent, were each screened for susceptibility
to P. infestans isolate MP 324 using detached leaf assays. Fifty seedling plant individuals of the F1 progeny were each resistant to this
specific isolate, similarly to the seedling plants resulting from self-pollination of the resistant R parent. Thirty seedling
plants obtained from self-pollination of the S parent were susceptible. Among a total of 180 F2 plants, the segregation ratio
between resistant and susceptible plants was approximately 3: 1. Among the 66 seedling plants of the BC1 progeny originating from crossing an F1 plant with the susceptible S parent, there were 26 susceptible and 40 resistant plants
to P. infestans. The segregation patterns obtained indicated monogenic dominant inheritance of resistance to P. infestans isolate MP 324 in S. nigrum acc. 984750019. This gene, conferring resistance to P. infestans, may be useful for the transformation of potato cultivars susceptible to late blight. 相似文献
12.
The effect of two chemical elicitors (acibenzolar-S-methyl benzo-[1,2,3]- thiadiazole-7-carboxylic acid S-methyl ester [Boost
500SC]) and salicylic acid in inducing resistance in tea plants against blister blight disease caused by Exobasidium vexans Massee, was studied. Treatments with elicitors resulted in reduced severity of blister blight disease in nursery plants on
challenge with the pathogen. There was a significant increase in the activities of defense enzymes like phenylalanine ammonia
lyase, peroxidase and β-1,3-glucanase on elicitor treatments in tea leaves challenged with the pathogen than on unchallenged
leaves. Acibenzolar-S-methyl (ASM) at 0.14% registered the lowest disease severity (25.2%), whereas treatments with salicylic
acid were inferior. Under field conditions, the application of ASM at 0.14% resulted in disease protection of 25%. When ASM
was applied in alternate rounds with a standard fungicide, the disease protection improved to 46.8%. The importance of incorporating
ASM as a component in integrated disease management and also its importance in organic tea cultivation is discussed. 相似文献
13.
Y. L. Wu G. J. Yi X. X. Peng 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(3):409-415
In order to accelerate breeding and selection for disease resistance to Fusarium wilt, it is important to develop bioassays
which can differentiate between resistant and susceptible cultivars efficiently. Currently, the most commonly used early bioassay
for screening Musa genotypes against Fusarium oxysporum f. sp. cubense (Foc) is a pot system, followed by a hydroponic system. This paper investigated the utility of in vitro inoculation of rooted banana plantlets grown on modified medium as a reliable and rapid bioassay for resistance to Foc. Using a scale of 0 to 6 for disease severity measurement, the mean final disease severities of cultivars expressing different
levels of disease reaction were significantly different (P ≤ 0.05). Twenty-four days after inoculation with Foc tropical race 4 at 106 conidia ml−1, the plantlets of two susceptible cultivars had higher final disease severities than that of four resistant cultivars. Compared
with ‘Guangfen No.1’, ‘Brazil Xiangjiao’ is highly susceptible to tropical race 4 and its mean final disease severity was
the highest (5.27). The plantlets of moderately resistant cultivar ‘Formosana’ had a mean final disease severity (3.53) lower
than that of ‘Guangfen No.1’ (4.33) but higher than that of resistant cultivars: ‘Nongke No.1’, GCTCV-119, and ‘Dongguan Dajiao’
(1.87, 1.73, and1.53, respectively). Promising resistant clones acquired through non-conventional breeding techniques such
as in vitro selection, genetic transformation, and protoplast fusion could be screened by the in vitro bioassay directly. Since there is no acclimatization stage for plantlets used in the bioassay, it helps to improve banana
breeding efficiency. 相似文献
14.
B. Wang C. L. Brubaker P. H. Thrall J. J. Burdon 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(4):541-551
Temporal variation in Fusarium oxysporum f. sp. vasinfectum (Fov) populations was determined by comparing the genetic diversity of pathogen isolates recovered from three consecutive cotton
crops (2002, 2004 and 2006) in the Boggabilla area of New South Wales, Australia. A total of 288 isolates were collected,
among which 25 distinct AFLP genotypes were identified. These genotypes were classified into two main groups corresponding
to known vegetative compatibility groups (VCG)—01111 and 01112. The Fov populations were dominated by four genotypes (I-A, I-B, II-A, II-B) that accounted for 87.5% of the isolates. Significant
temporal variation was observed in both sampled fields with 6.8% and 10.7% of total genetic variation being attributed to
differences among collections in different years. Genetic diversity based on Nei’s gene diversity and the Shannon-Wiener index
increased over time. Significant changes in the frequency of the dominant Fov genotypes were observed in one field, where genotype I-A declined from 84.8% to 40.0% over the study period (2002–2006),
while genotype I-B increased from 7.6% to 35.4%. Strong inter-genotype competition was detected in glasshouse bioassays with
93.4% of symptomatic plants sampled from dual inoculation trials being infected by single genotypes. Competition was differentially
mediated by cotton cultivars as the competitive ability of pathogen genotype I-B was enhanced on the resistant cultivar Sicot
189 relative to the susceptible cultivar Siokra 1–4. This suggests that host-mediated inter-genotype competition may play
an important role in temporal variation in Fov populations in the field. 相似文献
15.
Anita Haegi Simona De Felice Michele Scotton Laura Luongo Alessandra Belisario 《European journal of plant pathology / European Foundation for Plant Pathology》2017,147(4):787-801
Bread wheat (BW) and durum wheat (DW) are both strongly affected by Septoria tritici blotch caused by the hemibiotrophic fungus Zymoseptoria tritici. However, only the BW-Z. tritici pathosystem has been well studied so far. Here, we compared compatible interactions between Z. tritici and both BW and DW species at the cytological, biochemical and molecular levels. Fungal infection process investigations showed close spore germination and leaf penetration features in both interactions, although differences in the patterns of these events were observed. During the necrotrophic phase, disease severity and sporulation levels were associated in both interactions with increases of the two cell-wall degrading enzyme activities endo-β-1,4-xylanase and endo-β-1,3-glucanase as well as protease. An analysis of plant defense responses during the first five days post inoculation revealed inductions of GLUC, Chi4, POX and PAL and a repression of LOX gene expressions in both wheat species, although differences in kinetics and levels of induction or repression were observed. In addition, peroxidase, catalase, glucanase, phenylalanine ammonia-lyase and lipoxygenase activities were induced in both wheat species, while only weak accumulations of hydrogen peroxide and polyphenols were detected at the fungal penetration sites. Our study revealed overall a similarity in Z. tritici infection process and triggered wheat defense pathways on both pathosystems. 相似文献
16.
Harsh Garg Linda M. Kohn M. Andrew Hua Li Krishnapillai Sivasithamparam M. J. Barbetti 《European journal of plant pathology / European Foundation for Plant Pathology》2010,126(3):305-315
Sclerotinia stem rot caused by Sclerotinia sclerotiorum is a serious threat to oilseed production in Australia. Eight isolates of S. sclerotiorum were collected from Mount Barker and Walkway regions of Western Australia in 2004. Comparisons of colony characteristics
on potato dextrose agar (PDA) as well as pathogenicity studies of these isolates were conducted on selected genotypes of Brassica napus and B. juncea. Three darkly-pigmented isolates (WW-1, WW-2 and WW-4) were identified and this is the first report of the occurrence of
such isolates in Australia. There was, however, no correlation between pigmentation or colony diameter on PDA with the pathogenicity
of different isolates of this pathogen as measured by diameter of cotyledon lesion on the host genotypes. Significant differences
were observed between different isolates (P ≤ 0.001) in two separate experiments in relation to pathogenicity. Differences were also observed between the different Brassica genotypes (P ≤ 0.001) in their responses to different isolates of S. sclerotiorum and there was also a significant host × pathogen interaction (P ≤ 0.001) in both experiments. Responses between the two experiments were significantly correlated in relation to diameter
of cotyledon lesions caused by selected isolates (r = 0.79; P < 0.001, n = 48). Responses of some genotypes (e.g., cv. Charlton) were relatively consistent irrespective of the isolates of the pathogen
tested, whereas highly variable responses were observed in some other genotypes (e.g., Zhongyou-ang No. 4, Purler) against
the same isolates. Results indicate that, ideally, more than one S. sclerotiorum isolate should be included in any screening programme to identify host resistance. Unique genotypes which show relatively
consistent resistant reactions (e.g., cv. Charlton) across different isolates are the best for commercial exploitation of
this resistance in oilseed Brassica breeding programmes. 相似文献
17.
Plants have developed mechanisms to resist secondary infection upon inoculation with a necrotizing pathogen, chemical treatment
as well as treatment with some non-pathogenic microorganisms such as rhizosphere bacteria. This phenomenon has been variously
described as induced systemic resistance (ISR) or systemic acquired resistance. In the present study, the chemical benzo(1,2,3)thiadiazole-7-carbothioic
acid-S-methyl ester (BTH, acibenzolar-S-methyl), and the rhizobacteriaPseudomonas aeruginosa KMPCH andP. fluorescens WCS417 were tested for their ability to induce resistance toColletotrichum lindemuthianum in susceptible and moderately resistant bean plants (Phaseolus vulgaris L.). BTH induced local and systemic resistance when bean leaves were immersed in 10−3 to 10−7 M BTH 3 days before the challenge inoculation. At a high concentration (10−3 M), BTH induced resistance of the same order as resistance induced by the pathogenC. lindemuthianum, although at this high concentration BTH appeared to be phytotoxic. Soil and seed treatment with 1 mg kg−1 BTH protected beans against anthracnose. BTH-mediated induced resistance was effective in susceptible and moderately resistant
plants.P. aeruginosa KMPCH induced resistance in bean againstC. lindemuthianum only in a moderately resistant interaction. KMPCH-567, a salicylic acid mutant of KMPCH, failed to induce resistance, indicating
that salicylic acid is important for KMPCH to induce resistance in the bean—C. lindemuthianum system.P.fluorescens WCS417 could induce resistance toC. lindemuthianum in a susceptible and in moderately resistant interactions.
http://www.phytoparasitica.org posting Jan. 16, 2002. 相似文献
18.
H. D. Mbouobda Fotso P. F. Djocgoue N. D. Omokolo I. El Hadrami T. Boudjeko 《Phytoparasitica》2010,38(1):71-79
The root rot disease caused by Pythium myriotylum is responsible for about 70% of cocoyam production loss in Cameroon. The potential of benzo-(1,2,3)-thiadiazole-7-carbothioic
S-methyl ester (BTH) to trigger resistance in cocoyam (Xanthosoma sagittifolium) plants against P. myriotylum was investigated. Under controlled conditions, BTH was an efficient elicitor of some defense reactions in cocoyam. Application
of 0.2 mg ml−1 of BTH on leaves 7 days before inoculation of roots with P. myriotylum enhanced the activities of peroxidase (Pox) and polyphenoloxidase (PPO) as well as the total phenolic content. This resistance
was noted as a decrease in disease incidence and severity in BTH-treated plants. This increase in Pox activities was correlated
with two new isoforms in a white (sensitive) cultivar inoculated after stimulation. In a yellow (resistant) cultivar, stimulation
was characterized by the appearance of one isoform. Qualitative analysis of phenolic compounds by HPLC showed an increase
of hydroxycinnamic and flavonoid derivatives after inoculation. We also observed the appearance of a new caffeoylshikimic
acid derivative after stimulation followed by inoculation of both cultivars. The findings indicated that the pattern of induction
is different and depends on the variety. 相似文献
19.
M. I. Tajul Takayuki Motoyama Akikazu Hatanaka M. Sariah Hiroyuki Osada 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(1):91-100
Four green-odour compounds—trans-2-hexenal, cis-3-hexenol, n-hexanal, and cis-3-hexenal—were applied (0.85 μg ml−1 as vapour) to rice plants in laboratory conditions to observe their biological activity against the phytopathogenic fungus
Maganporthe oryzae, which causes rice blast disease worldwide. Two compounds, trans-2-hexenal and cis-3-hexenal, showed remarkable disease suppression efficacy (99.7% and 100% suppression, respectively), while n-hexanal had moderate (86.5%) and cis-3-hexenol had weak (20.8%) disease-suppressing effects. Pre-application and post-application of trans-2-hexenal or cis-3-hexenal had slight effects on blast incidence, suggesting that these compounds had direct effects to suppress M. oryzae infection. In fact, trans-2-hexenal and cis-3-hexenal exhibited a growth suppression effect on M. oryzae. Interestingly, these two compounds inhibited appressorium formation at lower concentrations than the growth suppression.
Studies on the hypersensitive response (HR)-like reaction and plant β-1,3-glucanase activity in rice plant confirmed that
induced resistance was not the major factor involved in the disease suppression mechanism. Results of this study conclusively
showed that trans-2-hexenal and cis-3-hexenal possess potent inhibitory activities against the growth and the appressorium formation of M. oryzae and could be used as antifungal agents to significantly reduce M. oryzae infections in rice. 相似文献
20.
The study was carried out to assess the reaction of different rice genotypes in response to brown planthopper (BPH)Nilaparvata lugens (Stål.) attack and the possible use of these genotypes in BPH management. The resistant genotypes PTB 33, ADT 45 and ASD 7 and the moderately resistant genotypes CO 43 and KAU 1661 recorded the lowest nymphal preference, fecundity, feeding rate, survival, growth index, population buildup and plant dry weight loss per mg of insect dry weight produced, and more unhatched eggs, longer nymphal development period, days to wilt and higher Functional Plant Loss Index compared with the susceptible genotype TN1. In resistant and moderately resistant genotypes, a greater accumulation of defense enzymes such as peroxidase and polyphenol oxidase in response toN. lugens infestation was recorded one day after infestation, and more pathogenesis-related protein and chitinase activity was noted 3 days after infestation. The activity was sustained for more than a week after infestation compared with the susceptible genotype TN1. 相似文献