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1.
Dvora Swartzberg Beny Kirshner Dalia Rav-David Yigal Elad David Granot 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(3):289-297
Botrytis cinerea is a non-specific, necrotrophic pathogen that attacks many plant species, including Arabidopsis and tomato. Since senescing leaves are particularly susceptible to infection by B. cinerea, we hypothesized that the fungus might induce senescence as part of its mode of action and that delaying leaf senescence
might reduce the severity of B. cinerea infections. To examine these hypotheses, we followed the expression of Arabidopsis SAG12, a senescence-specific gene, upon infection with B. cinerea. Expression of SAG12 is induced by B. cinerea infection, indicating that B. cinerea induces senescence. The promoter of SAG12, as well as that of a second Arabidopsis senescence-associated gene, SAG13, whose expression is not specific to senescence, were previously analyzed in tomato plants and were found to be expressed
in a similar manner in the two species. These promoters were previously used in tomato plants to drive the expression of isopentenyl
transferase (IPT) from Agrobacterium to suppress leaf senescence (Swartzberg et al. in Plant Biology 8:579–586, 2006). In this study, we examined the expression
of these promoters following infection of tomato plants with B. cinerea. Both promoters exhibit high expression levels upon B. cinerea infection of non-senescing leaves of tomato plants, supporting our conclusion that B. cinerea induces senescence as part of its mode of action. In contrast to B. cinerea, Trichoderma harzianum T39, a saprophytic fungus that is used as a biocontrol agent against B. cinerea, induces expression of SAG13 only. Expression of IPT, under the control of the SAG12 and SAG13 promoters in response to infection with B. cinerea resulted in suppression of B. cinerea-induced disease symptoms, substantiating our prediction that delaying leaf senescence might reduce susceptibility to B. cinerea.
Contribution from the Agriculture Research Organization, The Volcani Center, Bet Dagan, Israel, No. 127/2006 series. 相似文献
2.
M. Staats P. van Baarlen J. A. L. van Kan 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(3):219-235
The objective of this study was to assess the genetic diversity and to infer the mode of reproduction of Botrytis
elliptica and B. tulipae in the Netherlands. First, three molecular typing methods were compared for their ability to differentiate isolates of B. tulipae, B. elliptica, and B. cinerea. The methods compared were multilocus sequencing, restriction analysis of the ribosomal intergenic spacer (IGS) region, and
amplified fragment length polymorphism (AFLP) analysis. AFLP fingerprinting provided the most efficient method to differentiate
isolates within each Botrytis species and therefore this method was used for population analyses of B. elliptica and B. tulipae. Isolates of both species were sampled during successive growing seasons in experimental field plots in Lisse and other locations
in the Netherlands. Among 174 B. elliptica isolates, 105 genotypes could be discriminated and 87 genotypes were found only once, reflecting high genotypic variation.
Clonal genotypes were found only within growing seasons and in one location. Linkage disequilibrium analyses indicated that
between 9.4% and 19.3% of the loci in clone-corrected samples were linked. The multilocus association index provided no evidence
for random mating. We conclude that sexual recombination occurs in the B. elliptica population. Among the 170 B. tulipae isolates, 25 genotypes could be discriminated and four genotypes were found only once, reflecting a low genotypic variation.
Clonal genotypes were frequently found in different growing seasons and different locations. Linkage disequilibrium analyses
indicated that between 25.2% and 48.6% of the loci in clone-corrected samples were linked. We conclude that the B. tulipae population is mainly clonal with some recombination. 相似文献
3.
Duraisamy Saravanakumar Davide Spadaro Angelo Garibaldi M. Lodovica Gullino 《European journal of plant pathology / European Foundation for Plant Pathology》2009,123(2):183-193
Two antagonistic yeast strains Metschnikowia pulcherrima MACH1 and Rhodotorula sp. PW34 were tested for their efficacy against Botrytis cinerea in vitro and in vivo on apples. Metschnikowia pulcherrima strain MACH1 showed higher inhibition of B. cinerea compared to the strain PW34 in vitro on potato dextrose broth. Further, yeast strain MACH1 showed higher efficacy in reducing
grey mould on apples compared to PW34 and the untreated control. In addition, partially purified extracellular proteins from
strain MACH1 showed an inhibition to B. cinerea in vitro. The antagonistic yeast strains were tested for their efficacy to produce chitinases in different liquid media,
including apple juice, amended with or without cell wall preparations (CWP) of B. cinerea. The study showed a higher production of chitinases from M. pulcherrima strain MACH1 when compared to PW34. Interestingly, the strain MACH1 secreted higher chitinases in the presence of cell wall
fractions of B. cinerea. For this reason, the chitinase gene of strain MACH1 was amplified using PCR reactions and the nucleotide sequence data showed
high homology to chitinases of other yeast strains. The results of the current study show that M. pulcherrima strain MACH1 has the ability to secrete chitinases in different liquid media including apple juice, and the enzyme could
be involved in the post-harvest biological control of B. cinerea. 相似文献
4.
Mutants of Botrytis cinerea and Ustilago maydis highly resistant to fludioxonil were isolated at a high frequency, after nitrosoguanidine or UV mutagenesis, respectively,
and selection on media containing fludioxonil. Tests on the response of mutant strains to high osmotic pressure resulted in
the identification of two fludioxonil-resistant phenotypes (FLDosm/s and FLDosm/r), regarding the sensitivity to high osmolarity. Approximately 95% of fludioxonil-resistant mutants were found to be more
sensitive to high osmotic pressure than the wild-type parent strains. Genetic analysis of phenylpyrrole-resistance in the
phytopathogenic basidiomycete U. maydis, showed that fludioxonil-resistance was coded by three unlinked chromosomal loci (U/fld-1, U/fld-2 and U/fld-3), from which only the U/fld-1 mutation coded an osmotic sensitivity similar to that of the wild-types. Cross-resistance studies with fungicides from
other chemical groups showed that the mutations for resistance to phenylpyrroles affect the sensitivity of mutant strains
to the aromatic hydrocarbon and dicarboximide fungicides, but not to the benzimidazoles, anilinopyrimidines, phenylpyridinamines,
hydroxyanilides or the sterol biosynthesis inhibiting fungicides. A study of fitness parameters in the wild-type and fludioxonil-resistant
mutants of B. cinerea, showed that all osmotic sensitive (B/FLDosm/s) isolates had significant reductions in the characteristics determining saprophytic fitness such as mycelial growth, sporulation,
conidial germination and sclerotial production. Contrary to that, with the exception of mycelial growth, the fitness parameters
were unaffected or only slightly affected in most of the osmotic resistant (B/FLDosm/r) isolates. Tests on cucumber seedlings showed that the osmotic-sensitive strains were significantly less pathogenic compared
with the wild-type and B/FLDosm/r strains of B. cinerea. Preventative applications of the commercial products Saphire 50 WP (fludioxonil) and Rovral 50 WP (iprodione) were effective
against lesion development on cotyledons by the wild-type and the mutant strains of B. cinerea that were resistant to the anilinopyrimidine cyprodinil (B/CPL-27) and to the hydroxyanilide fenhexamid (B/FNH-21), but ineffective,
even at high concentrations, against disease caused by the fludioxonil-resistant isolates (B/FLD) and a mutant strain resistant
to the dicarboximide iprodione (B/IPR-1). Experiments on the stability of the fludioxonil-resistant phenotype showed a reduction
of resistance, mainly in osmotic-sensitive isolates, when the mutants were grown on inhibitor-free medium. A rapid recovery
of the high resistance was observed after mutants were returned to the selection medium. Studies on the competitive ability
of mutant isolates against the wild-type parent strain of B. cinerea, by applications of a mixed conidial population, showed that, in vitro, all mutants were less competitive than the wild-type strain. However, the competitive ability of osmotic-resistant mutants
was higher than the osmotic-sensitive ones. Furthermore, competition tests, in planta, showed a significant reduction of the frequency of both phenylpyrrole-resistant phenotypes, with a respective increase in
the population of the wild-type strain of the pathogen. 相似文献
5.
为明确植物病原真菌禾谷镰刀菌Fusarium graminearum全生活史的转录组特征和基因表达模式,采用生物信息学技术对其生活史不同阶段15个时期或组织的链特异性RNA-seq数据进行分析。结果表明,共有8 106个基因在所有时期均有表达,为禾谷镰刀菌生活史核心基因,占总基因数的47.2%;有性生殖和侵染过程中表达的基因数相对较多,其中有性生殖后期表达的基因数最多,达15 221个;无性产孢和侵染小麦穗过程中基因表达水平整体较高,而分生孢子中基因表达水平最低。在燕麦培养基上禾谷镰刀菌气生菌丝的基因表达模式与侵染过程中的基因表达模式较为相似,而与营养生长菌丝的基因表达模式差异较大。该菌次生代谢物合成特征酶基因和分泌蛋白基因的表达模式均分成3类,即分别在侵染、营养生长和有性生殖过程上调表达,暗示其在生活史不同阶段的特异性功能。 相似文献
6.
Partial stem and leaf resistance against the fungal pathogen <Emphasis Type="Italic">Botrytis cinerea</Emphasis> in wild relatives of tomato 总被引：3，自引：0，他引：3
Arjen ten Have Ralph van Berloo Pim Lindhout Jan A. L. van Kan 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(2):153-166
Tomato (Solanum lycopersicum) is one of many greenhouse crops that can be infected by the necrotrophic ascomycete Botrytis cinerea. Commercial cultivation of tomato is hampered by the lack of resistance. Quantitative resistance has been reported in wild
tomato relatives, mostly based on leaf assays. We aimed to identify wild tomato relatives with resistance to B. cinerea based on quantitative assays both on leaves and stem segments, monitoring infection frequency and disease expansion rate
as parameters. A quantitative tomato stem segment assay was developed. This stem assay and a previously described leaf assay
were used to screen a collection of 22 Solanum accessions. Significant differences in disease parameters were observed among accessions. Resistance to B. cinerea was observed in a number of wild Solanum species, including accessions of S. chilense, S. habrochaites and S. neorickii, both in the leaf assay and the stem segment assay. A number of resistant and susceptible accessions were evaluated as adult
plants under greenhouse conditions. The data obtained in greenhouse assays confirmed the leaf and stem disease data. The expression
of several defence-related genes was studied in a subset of accessions. There was no apparent correlation between the expression
levels of the genes tested and the quantitative resistance level to B. cinerea.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
7.
8.
Francesco Faretra Stefania Pollastro Francisco Sansiviero 《Pest management science》1992,35(2):171-174
‘Aliette’, a formulation of the fungicide fosetyl-aluminium, is moderately active in vitro against the ascomycete Botryotinia fuckeliana (Botrytis cinerea). In contrast, fosetyl-aluminium and related chemicals, such as phosphonic acid and sodium phosphonate, have low efficacy, although it is enhanced by media with low phosphate content. This indicates that the effectiveness of ‘Aliette’ against B. fuckeliana is not due to fosetyl-aluminium but to adjuvants included in the formulation. The genetic basis of differences in sensitivity to ‘Aliette’ was investigated in field and laboratory isolates of B. fuckeliana. Genetic analysis showed that reduced sensitivity to ‘Aliette’ always co-segregated with resistance to benzimidazole fungicides in meiotic progeny of sexual crosses. This indicates that differences in sensitivity to ‘Aliette’ in B. fuckeliana are due to the major gene Mbcl of resistance to benzimidazole fungicides and active adjuvant(s) present in ‘Aliette’ are linked to benzimidazoles by cross-resistance. 相似文献
9.
玉米大斑病菌两性交配型菌株的出现频率及其育性分析 总被引：1，自引：1，他引：0
玉米大斑病菌属于异宗配合真菌,在自然界中存在A、a交配型菌株和Aa两性交配型菌株,为明确两性菌株的出现频率及其对有性生殖的影响,采用有性态诱导和交配型PCR鉴定的方法,对2011—2014年采集的野生菌株及室内诱导产生的有性杂交后代F1、F2代进行交配型组成鉴定,通过检测两性菌株子囊壳和子囊孢子的发育情况明确其有性生殖能力,结合RT-PCR技术对有性生殖过程中MAT1和MAT2基因的表达情况进行分析。结果表明,野生菌株和有性杂交后代中均存在两性交配型菌株,且出现频率相当,介于2.09%和6.25%之间;Aa两性菌株的育性与杂交时对应菌株的交配型组成相关,两性菌株与A交配型菌株或a交配型菌株杂交均可育,能产生成熟的子囊壳和子囊孢子,但其自交时败育,只产生子囊壳,不产生子囊孢子。两性菌株Aa自交和两性菌株Aa与A交配型或与a交配型菌株杂交时,Aa菌株中MAT1和MAT2基因表达量无明显差异,推测MAT基因在有性生殖产生子囊壳的过程中发挥了重要作用。 相似文献
10.
María M. Reynoso Sofía N. Chulze Kurt A. Zeller Adriana M. Torres John F. Leslie 《European journal of plant pathology / European Foundation for Plant Pathology》2009,123(2):207-215
Fusarium verticillioides (sexual stage Gibberella moniliformis) is a common fungal pathogen of maize worldwide that also produces fumonisin mycotoxins. Populations of this fungus can be
diverse with respect to neutral and selectable genetic markers. We used vegetative compatibility groups (VCGs) and amplified
fragment length polymorphisms (AFLPs) to evaluate the genetic structure of three F. verticillioides populations from commercial maize fields in Argentina. Based on work with similar populations from outside South America,
we expected individuals within the populations to be genetically diverse, that genotypic variation would be distributed in
a manner consistent with random mating, and that populations from different locations would be genetically indistinguishable
from one another. We analysed 62 AFLP loci for 133 fungal isolates. All three populations were genotypically diverse but genetically
similar and potentially part of a larger, randomly mating population, with significant genetic exchange occurring between
the three subpopulations. There was no evidence for linkage disequilibrium at P = 0.05. The low values of G
ST
, the lack of frequent private alleles, and the lack of a systemic pattern of linkage disequilibrium all suggest that sexual
reproduction is sufficiently common in F. verticillioides and that the dispersal of strains is sufficiently efficient for the population of F. verticillioides in the main maize growing region to be a single randomly mating population with no detectable genetic subdivision. Thus differences
in disease and/or toxin production observed in this region are best attributed to differences other than the genetic composition
of the population. 相似文献
11.
Genetic structure and fungicide sensitivity of Botrytis cinerea populations isolated from grapevine in northern Italy 
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下载免费PDF全文 P. Campia G. Venturini P. Moreno‐Sanz P. Casati S. L. Toffolatti 《Plant pathology》2017,66(6):890-899
Grey mould, caused by Botrytis cinerea, is a disease severely affecting grape production in northern Italy. However, little information is available on the variability of B. cinerea populations associated with grapevine. The mode of reproduction, sensitivity to fungicides, and for the first time in Italy, the genetic structure of B. cinerea populations isolated from grapevine in a northern Italian region are reported. Botrytis cinerea isolates (317) were completely genotyped for six microsatellite loci and characterized for the presence of the transposable elements Boty and Flipper, for the mating type and for resistance to cyprodinil, fludioxonil, boscalid and fenhexamid. All the isolates were found to belong to B. cinerea Group II, indicating the absence of B. pseudocinerea in the investigated areas. The populations possess a high genotypic diversity, different frequencies of transposable elements and a mixed mode of reproduction. At a regional level, B. cinerea populations belong to a large and interconnected pathogen population that includes the major grape‐growing districts. The populations were generally sensitive to fungicides, with a low proportion (8%) of isolates resistant to cyprodinil, fludioxonil and boscalid. A small genetic distance was found between B. cinerea populations. However, the populations geographically isolated from the others by a mountain range showed a small but statistically significant genetic differentiation and a different pattern of fungicide resistance. The results show that northern Italian B. cinerea populations possess a high evolutionary potential and adaptive capacity. 相似文献
12.
Pedro Boff Pieter Kastelein Joop de Kraker Matthijs Gerlagh Jürgen Köhl 《European journal of plant pathology / European Foundation for Plant Pathology》2001,107(6):615-624
The epidemiology of Botrytis cinerea was studied in five annual strawberry crops using waiting-bed transplants, a system widely adopted in the Netherlands. On dead leaves of transplants the incidence of B. cinerea varied from 26.7% to 52.6%, but the leaf area with potential sporulation was low (3.5–15.6%). During each crop cycle, the availability of necrotic leaf substrate for spore production of B. cinerea was generally low and varied between seasons and with the quality of transplants. B. cinerea sporulated on a maximum of 15.5 cm2 of leaf area per plant, measured as potential sporulation. The aerial concentration of B. cinerea conidia in untreated plots did not differ from the concentration in plots where all dead leaves had been removed, nor from the concentration at 25–50 m distance from the strawberry plots. B. cinerea incidence on flowers ranged from 5% to 96%, but no correlation was found with the potential spore production on necrotic leaves. Grey mould at harvest varied from 1.4% to 11.3% and was correlated with the average precipitation during the harvesting period but not with B. cinerea incidence on flowers. Post-harvest grey mould ranged from 2.1% to 32.6% and was correlated with petal colonisation by B. cinerea. The results suggest that in the annual cropping system with waiting-bed transplants, necrotic leaves are not a significant source of B. cinerea inoculum, unlike in other strawberry production systems. Therefore, control measures of grey mould in this annual system should focus on protection of flowers and young developing fruits, and not on the reduction of inoculum production on leaf debris. 相似文献
13.
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
14.
Population structure of the rice sheath blight pathogen <Emphasis Type="Italic">Rhizoctonia solani</Emphasis> AG-1 IA from India 总被引：1，自引：0，他引：1
The population structure of Rhizoctonia solani AG-1 IA causing rice sheath blight from India was evaluated for 96 isolates using seven RFLP loci. Nineteen of the isolates did not hybridise to R. solani AG-1 IA RFLP probes and rDNA analyses subsequently confirmed that they were either Ceratobasidium oryzae-sativae isolates or another Rhizoctonia sp. The population structure of the remaining 77 R. solani AG-1 IA Indian isolates was similar to that of a previously characterized Texas population. Clonal dispersal of R. solani AG-1 IA in India was moderate within fields and no clones were shared among field populations. Low levels of population subdivision and small genetic distances among populations were consistent with high levels of gene flow. Frequent sexual reproduction was indicated by the fact that most populations were in Hardy–Weinberg equilibrium (HWE). The two loci (R68 and R111) that deviated significantly from HWE showed an excess of heterozygosity. Although Texas and Indian populations were geographically very distant, they exhibited only moderate population subdivision, with an FST value of 0.193. 相似文献
15.
Laura Cortada F. Javier Sorribas César Ornat Maria Fé Andrés Soledad Verdejo-Lucas 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(2):337-343
The response of four Mi-resistance gene tomato rootstocks to seven populations of Meloidogyne was determined in pot tests conducted in a glasshouse. Rootstocks PG76 (Solanum lycopersicum × Solanum sp.) and Brigeor (S. lycopersicum × S. habrochaites) and resistant cv. Monika (S. lycopersicum) were assessed against one population of M. arenaria, three of M. incognita, and three of M. javanica. Rootstocks Beaufort and Maxifort were assessed against one population of M. arenaria, two of M. incognita and two of M. javanica. Rootstock PG76 was highly resistant (reproduction index <10%) to all the populations, whereas rootstock Brigeor and cv.
Monika were highly to moderate resistant. Rootstocks Beaufort and Maxifort showed reduced resistance or inability to suppress
nematode reproduction, and their responses varied according to the population tested. Beaufort and Maxifort were susceptible
to the two populations of M. javanica as Maxifort was to one of M. incognita. The reproduction index of the nematode was higher (P < 0.05) on Maxifort than Beaufort for all root-knot nematode populations. 相似文献
16.
17.
Genetic population structure and fungicide resistance of Botrytis cinerea in pear orchards in the Western Cape of South Africa 下载免费PDF全文
下载免费PDF全文 Botrytis cinerea isolates from pear blossoms (Pyrus communis) in South Africa were collected from four orchards in two production areas in the Western Cape. The cryptic species status based on vegetative‐incompatibility alleles of the Bc‐hch gene indicated that all the isolates belonged to B. cinerea. A microsatellite analysis of B. cinerea populations was performed to assess the genetic population structure. Total gene diversity (H) was high, with a mean of 0.69 across all populations. Some genotype flow was evident between orchards as indicated by the spread of microsatellite multilocus genotypes, in agreement with the moderate, but significant population differentiation among orchards (mean φPT = 0.118, P = 0.001). Index of association analyses (IA and r?d) suggest that the populations reproduce mostly asexually, even though mating type distribution did not differ significantly from a 1:1 ratio, suggesting frequency‐dependent selection. Isolates resistant to benomyl were evident in one orchard only. This orchard was also significantly differentiated from all other populations, suggesting infrequent localized selection for benomyl resistance. Overall, the findings of this study highlight the dangers of a mixed reproduction system, and stress the importance of regularly monitoring fungicide resistance levels towards developing more efficient management practices. 相似文献
18.
Cytological characteristics of microconidia of <Emphasis Type="Italic">Magnaporthe oryzae</Emphasis>
Izumi Chuma Takeshi Shinogi Naoki Hosogi Ken-ichi Ikeda Hitoshi Nakayashiki Pyoyun Park Yukio Tosa 《Journal of General Plant Pathology》2009,75(5):353-358
The inner cellular structure of microconidia of Magnaporthe oryzae was examined using fluorescent probes and electron microscopic techniques. The volume of the nucleus relative to the cell
was significantly larger in microconidia than in macroconidia or vegetative hyphae, similar to observations for spermatia
of other fungi. Selective fluorescent staining revealed that cytosolic RNA was less abundant in microconidia than in macroconidia
and germ tubes, suggesting that general metabolic activity in microconidia is low. Consistently, GFP expression driven by
the TrpC promoter was highly active during the formation of phialides and microconidia but gradually decreased as the microconidia
matured. Such data suggest that microconidia are in a quiescent or dormant state. 相似文献
19.
Yigal Cohen Avia E. Rubin 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(4):577-592
The oomycete Pseudoperonospora cubensis is a leaf pathogen causing severe damage to members of the Cucurbitaceae, especially cucumber and melon. It propagates clonally by sporangia. Oospores of P. cubensis were previously observed in nature but their formation in the laboratory was never reported nor their germination or infection.
Here we report on the sexual reproduction of P. cubensis under controlled conditions in the laboratory. When field isolates were inoculated singly onto detached leaves of cucurbits
in growth chambers no oospores were produced. However, when pairs of selected isolates were mixed and inoculated onto detached
leaves, oospores were formed in the mesophyll within 6–11 days, suggesting that P. cubensis is heterothallic, having two opposite mating types, A1 and A2. Isolates belonging to pathotype 3 were all A1 whereas isolates
belonging to the new pathotype 6 were either A1 or A2. Oospores were spherical, ~40 μm in diameter, hyaline to red-brown in
color. Oospores were produced regularly, in large numbers, in Cucumis sativum and Cucumis melo, very seldom and in very small numbers in Cucurbita pepo, Cucurbita maxima and Citrullus lanatus, and not in Cucurbita moschata. Oospores were formed at 12.5–21°C but not at 25°C. Under moisture-saturated atmosphere oospores were also produced in leaves
of intact plants. Oospores inoculated onto detached leaves in growth chambers produced F1 downy mildew lesions at 6–21 days
after inoculation, many in Cucumis sativum, Cucumis melo and Cucurbita moschata, very few in Cucurbita pepo or Citrullus lanatus, and none in Cucurbita maxima. This report shows that P. cubensis is heterothallic, having A1 and A2 mating types which can cross and enable sexual reproduction in cucurbits. A preliminary
report on part of the results has been published earlier. 相似文献
20.
BHT对苹果采后灰霉病的防效及防御酶活性和丙二醛含量的影响 总被引：1，自引：1，他引：0
为探究2,6-二叔丁基-4-甲基苯酚(2,6-di-tert-butyl-4-methylphenol,BHT)对苹果采后灰霉病的防效和防病机制,采用平板法和刺伤接种法测定了BHT对灰霉病菌Botrytis cinerea的抑制作用及果实内防御酶活性和丙二醛含量的影响。结果表明,0.1 mmol/L BHT对苹果灰霉病的防效最佳,处理苹果后间隔48～96 h接种灰霉病菌,其防效可达68.59%～73.55%,其次为0.2、1.0 mmol/L BHT处理,但防效均低于52.94%。0.1 mmol/L BHT处理对灰霉病菌菌丝生长和分生孢子萌发无显著抑制作用,但可显著增强果实内超氧化物歧化酶、过氧化物酶和过氧化氢酶的活性以及总抗氧化能力,其峰值是对照的1.82～5.28倍,且均显著高于单独接种灰霉病菌的处理。此外,单独接种灰霉病菌的苹果果实内丙二醛含量快速升高,最大增幅达251.49%,而BHT处理后丙二醛含量变幅较小,最大增幅仅为83.95%。表明BHT可通过增强苹果果实内防御酶活性水平和总抗氧化能力来降低丙二醛的积累,从而提高果实对灰霉病的抗性。 相似文献