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1.
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2.
In a collection of 735 Botrytis isolates sampled from Australian wine grape-growing regions, a single isolate from clade I and group I (based on Bc-hch RFLP analysis) was found. As many Botrytis species are known to live sympatrically, it was hypothesized that this isolate might be a new Botrytis species. After phenotypic and molecular assays supported this hypothesis, the species was designated B. medusae. Phylogenetic analyses using the nuclear genes G3PDH, HSP60, RPB2, NEP1 and NEP2 consistently placed B. medusae in an early-diverging clade I Botrytis spp. lineage. Botrytis medusae produced white aerial mycelium, grew faster at 30 °C and produced long-branched conidiophore extensions, compared with B. cinerea and B. pseudocinerea. Botrytis medusae was only able to infect wounded grape leaves and was significantly less virulent on wounded leaves and berries than B. cinerea. Botrytis medusae also lacked villiform appendages on the conidial surface and long conidiophores, which are defining features of B. sinoviticola and B. californica, respectively. Identification and characterization of new cryptic Botrytis species living in sympatry on grapevines could potentially provide information to assist disease management strategies for B. cinerea.  相似文献   

3.
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   

4.
An unknown disease abruptly appeared on hydroponic cultures of common ice plant (Mesembryanthemum crystallinum) in the greenhouse, causing catastrophic damage. Although the symptoms of the plant were unlike typical Botrytis lesions on leaves and stems of other plants, fungi isolated from the necrotic lesions on the plant were similar to genus Botrytis in terms of conidial shape, colony color and nature. A representative isolate, Ice-2, caused similar symptoms on the host plants after inoculation with conidia, and the same fungus was isolated from the lesions. The conidia and conidiophores of Ice-2 were morphologically similar to those of B. cinerea but not to those of B. allii, B. fabae or B. squamosa. The tested Botrytis fungi grew at temperatures between 5 and 30°C. Ice-2 grew faster than the others at the lower end of the temperature range. Ice-2 was also more virulent than B. cinerea (Bay-1) in artificial inoculations, especially on common ice plant leaves. The glyceraldehyde-3-phosphate dehydrogenase gene (G3PDH) sequence of Ice-2 was determined and compared with those from four Botrytis species. The gene sequence of Ice-2 appeared to be identical to that of B. cinerea. In leaf tests on common ice plant and kidney bean, the diseases caused by Ice-2 and Bay-1 were controlled equally well by the primary Botrytis fungicides. Based on the results of the present studies, Ice-2 is thought to be Botrytis cinerea Person: Fries.  相似文献   

5.
Grey mould is reported in the vineyards of Castilla y León, Spain, every year. However, the natural populations of the pathogen have yet to be properly characterized. Vineyards from six wine-producing areas were surveyed in 2002 and 2007, sampling from bunches of grapes with and without symptoms. A total of 283 Botrytis field isolates were selected for physiological and genetic analyses. Botrytis cinerea isolates predominated in the population, although isolates belonging to Botrytis pseudocinerea and Botrytis prunorum were also identified. These two species are recorded for the first time in Spain in this work. In addition, two isolates closely related to Botrytis californica were identified. Physiologically, the B. cinerea population is very diverse, displaying a normal distribution of aggressiveness values in Vitis vinifera leaves, suggesting a quantitative nature for this trait. Several isolates unable to cause infection were identified, most of them belonging to a mycelial morphotype. Population genetic analysis revealed that genotypic diversity is high and that multiple infections of the same bunch of grapes by different genotypes occur frequently. The high genotypic diversity observed, an even distribution of both mating types and the linkage disequilibrium values detected support a mixed mode of reproduction with low levels of clonality. The wine-producing area in which each isolate was collected imposed a low degree of population differentiation, an effect that does not depend solely on the geographic distances but rather on the management practices used by growers and wine producer associations.  相似文献   

6.
This study tested the hypothesis that aggressive, localized infections and asymptomatic systemic infections were caused by distinct specialized groups of Botrytis cinerea, using microsatellite genotypes at nine loci of 243 isolates of B. cinerea obtained from four hosts (strawberry (Fragaria×ananassa), blackberry (Rubus fruticosus agg.), dandelion, (Taraxacum officinale agg.) and primrose (Primula vulgaris)) in three regions in southern England (in the vicinities of Brighton, Reading and Bath). The populations were extremely variable, with up to 20 alleles per locus and high genic diversity. Each host in each region had a population of B. cinerea with distinctive genetic features, and there were also consistent host and regional distinctions. The B. cinerea population from strawberry was distinguished from that on other hosts, including blackberry, most notably by a common 154‐bp amplicon at locus 5 (present in 35 of 77 samples) that was rare in isolates from other hosts (9/166), and by the rarity (3/77) of a 112‐bp allele at locus 7 that was common (58/166) in isolates from other hosts. There was significant linkage disequilibrium overall within the B. cinerea populations on blackberry and strawberry, but with quite different patterns of association among isolates from the two hosts. No evidence was found for differentiation between populations of B. cinerea from systemically infected hosts and those from locally infected fruits.  相似文献   

7.
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   

8.
An analysis of allelic diversity at nine microsatellite loci provided an insight into the population structure of Botrytis cinerea from four fields (sampled in 2003 and 2004) that represented important regional locations for chickpea production in Bangladesh. Although three populations were limited by sample size after clone‐correction, a total of 51 alleles were amplified among 146 B. cinerea isolates from Bangladesh, which revealed a high amount of within‐population and overall genetic diversity (HS = 0·48 and HT = 0·54, respectively). The percentage of maximal genotypic diversity (G) ranged between populations (G = 23–40), with a total of 69 haplotypes detected (G = 25). Bayesian cluster analysis depicted two major clusters distributed among the four Bangladesh populations, indicating population admixture from two origins that have spread throughout these regions. Genotype flow between regions was detected and indicated the spread of clonal lineages, consistent with relatively low differentiation among the four populations (mean GST = 0·1, P < 0·05). These results highlighted the potential threat of host resistance breakdown as a result of considerable genetic diversity, genotype flow and the evolutionary potential of B. cinerea.  相似文献   

9.
Biological control of Botrytis spp. by the fungal antagonist Ulocladium atrum is based on their interaction in plant tissue. U. atrum is effective against B. cinerea in commercial cyclamen crops but not effective against B. elliptica in lily crops. Based on the necrotrophic nature of the Botrytis spp. and the saprophytic nature of U. atrum it is hypothesised, and experimentally confirmed, that the interaction between Botrytis spp. and U. atrum, resulting in a biocontrol effect, only takes place in necrotic plant tissue. The role of necrotic tissue in the epidemiology of B. cinerea in cyclamen and B. elliptica in lily was found to be different. Removal of symptomless senescing leaves resulted in a significant reduction of the area under the disease severity progress curve (AUDPC) for B. cinerea in cyclamen but had no effect on the disease severity in lily. U. atrum applications significantly reduced B. cinerea AUDPC values in cyclamen but were less efficient than the removal of senescing leaves. In lily, disease severity was not affected by applications of U. atrum. It is concluded that necrotic cyclamen tissue, not killed by B. cinerea, plays an important role in the onset of disease. Colonisation of this tissue by U. atrum prevents saprophytic colonisation of those leaves by B. cinerea. In contrast, conidia of B. elliptica directly infect healthy lily leaf tissue. U. atrum applications aimed at blocking the infection pathway from a saprophytic base are therefore not effective against B. elliptica. Control options based on competitive interactions in and around B. elliptica lesions resulted in a reduced production of conidia by B. elliptica but proved ineffective against disease development. The potential of U. atrum as a biocontrol agent against Botrytis spp. and possibly against other necrotrophs appears to be determined by the competitive saprophytic ability of the antagonist in mutual substrates of pathogen and antagonist and by the role of these substrates in disease epidemiology.  相似文献   

10.
Between 2003 and 2005, 337 isolates of Botrytis cinerea collected from greenhouse vegetables were characterized for resistance to fungicides. A low level of chlorothalonil resistance was detected and in these resistant isolates there was cross-resistance to captan and thiram. To the best of our knowledge, this is the first report of chlorothalonil resistance in B. cinerea from vegetables in China. The sub-population of B. cinerea highly resistant to benzimidazoles developed quickly during the years 2003 to 2005. Rapid spread of double resistance to benzimidazoles and diethofencarb was also observed. Resistance to dicarboximides was of low-level character and no highly resistant isolates were detected. In contrast, emergence of resistance to pyrimethanil, the only anilinopyrimidine fungicide used in China at present, was detected in 2003 just 3 years after pyrimethanil introduction. Pyrimethanil-resistant isolates demonstrated fitness comparable with that of wild sensitive isolates. These results suggest that pyrimethanil has a high risk of leading to resistance development in B. cinerea in greenhouse vegetables.  相似文献   

11.
Experiments are presented which show that Botrytis cinerea, the cause of grey mould disease, is often present in symptomless lettuce plants as a systemic, endophytic, infection which may arise from seed. The fungus was isolated on selective media from surface-sterilised sections of roots, stem pieces and leaf discs from symptomless plants grown in a conventional glasshouse and in a spore-free air-flow provided by an isolation propagator. The presence of B. cinerea was confirmed by immuno-labelling the tissues with the Botrytis-specific monoclonal antibody BC-12.CA4. As plants grew, infection spread from the roots to stems and leaves. Surface-sterilisation of seeds reduced the number of infected symptomless plants. Artificial infection of seedlings with dry conidia increased the rate of infection in some experiments. Selected isolates were genetically finger-printed using microsatellite loci. This confirmed systemic spread of the inoculating isolates but showed that other isolates were also present and that single plants hosted multiple isolates. This shows that B. cinerea commonly grows in lettuce plants as an endophyte, as has already been shown for Primula. If true for other hosts, the endophytic phase may be as important a component of the species population as the aggressive necrotrophic phase.  相似文献   

12.
The objective of this work was to estimate the risk of a decrease in the efficacy of biocontrol as a result of selection pressure exerted by biocontrol agents on Botrytis cinerea, focusing on pyrrolnitrin, an antibiotic identified in diverse biocontrol agents having an effect on B. cinerea. To evaluate a possible decrease in sensitivity to pyrrolnitrin, 10 successive generations of five isolates of B. cinerea were produced in vitro in the presence of a sublethal dose (10 μg L?1) of the antibiotic. For one isolate, a significant reduction in the sensitivity to pyrrolnitrin at the fifth generation was observed with a resistance factor of c. 11. The production of 10 additional generations for four of these isolates, with increasing doses of pyrrolnitrin (100–4000 μg L?1), resulted in the development of variants of B. cinerea with high levels of resistance to the antibiotic (RF > 1000) and a reduced sensitivity in vitro to a pyrrolnitrin‐producing bacterium. Reverse adaptation of resistant variants after 10 additional generations in the absence of selection pressure was not observed, suggesting stability of the resistance. Comparison of the pyrrolnitrin‐resistant generations and their sensitive parental isolates for mycelial growth, sporulation and aggressiveness on plant tissues revealed that the high level of resistance to pyrrolnitrin resulted in a high fitness cost. Mycelial growth was reduced between 1·7 to 3·6 times and sporulation reduced 3·8 to 6·6 times that of sensitive parental isolates. Similarly, aggressiveness was 7 to 10 and 3 to 10 times lower for resistant isolates on tomato and apple, respectively. This study provides evidence that a fungal plant pathogen is able to gradually build up resistance to an antibiotic produced by a biocontrol agent.  相似文献   

13.
Control of grey mould, caused by Botrytis spp., is a major challenge in open field strawberry production. Botrytis was isolated from plant parts collected from 19 perennial strawberry fields with suspected fungicide resistance in the Agder region of Norway in 2016. Resistance to boscalid, pyraclostrobin and fenhexamid was high and found in 89.1%, 86.0% and 65.4% of conidia samples, respectively. Multiple fungicide resistance was common; 69.6% of conidia samples exhibited resistance to three or more fungicides. Botrytis group S and B. cinerea sensu stricto isolates were obtained from 19 and 16 fields, respectively. The sdhB, cytb, erg27 and mrr1 genes of a selection of isolates were examined for the presence of mutations known to confer fungicide resistance to boscalid, pyraclostrobin, fenhexamid and pyrimethanil plus fludioxonil, respectively. Allele-specific PCR assays were developed for efficient detection of resistance-conferring mutations in cytb. Among B. cinerea isolates, 84.7%, 86.3% and 61.3% had resistance-conferring mutations in sdhB, cytb and erg27, respectively. A triplet deletion in mrr1, resulting in ΔL497, commonly associated with the multidrug resistance phenotype MDR1h, was detected in 29.2% of Botrytis group S isolates. High frequencies of resistance to several fungicides were also detected in Botrytis from both imported and domestically produced strawberry transplants. Fungicide resistance frequencies were not different among fields grouped by level of grey mould problem assessed by growers, indicating factors other than fungicide resistance contributed to control failure, a fact that has important implications for future management of grey mould.  相似文献   

14.
Botrytis cinerea causes grey mould, a disease common on many economically important crops. Although much attention is paid to the airborne inoculum of this fungus, as it sporulates abundantly in favourable conditions, knowledge on the abundance and genetic characteristics of soilborne inoculum could help improve control strategies. In this study, the soilborne inoculum of B. cinerea was quantified in two greenhouses at different times before and after the cultivation of four successive lettuce crops. Between 0 and 1177 colony‐forming units (CFU) of B. cinerea per gram of soil were recorded. There was no significant correlation between abundance of soilborne inoculum and subsequent disease incidence on lettuce (P = 0·11). Sixty‐five isolates collected from diseased plants and 66 isolates collected from the soil were investigated for their genetic diversity. The soil strains showed lower genetic diversity than the lettuce strains when considering the unbiased gene diversity within the nine microsatellite loci, the mean number of alleles per locus and the haplotypic diversity. The genetic differentiation between lettuce and soil strains decreased over three successive lettuce crops. At the same time, the genetic structure of the two groups of strains tended to become similar. These results are consistent with the hypothesis of a flow of inoculum between the lettuce crop and the soil, and vice versa. The study shows that grey mould management should pay more attention to the inoculum of B. cinerea present in the soil.  相似文献   

15.
We investigated if rates of propagation and migration were related with the level of virulence in the pinewood nematode Bursaphelenchus xylophilus using 17 offspring lines from the F2 crosses between virulent and avirulent isolates. Virulence was tested by inoculating seedlings of Pinus thunbergii with the nematodes. The proportion of dead seedlings ranged from 13.3% to 77.8%, 20 weeks after inoculation. Migration rate of the nematodes was estimated by measuring their migration distance per unit time in an artificial substrate that imitated pathways in pine trees. Migration rate varied from 0.85 to 3.53 mm min−1. Propagation rate was determined based on population growth on the fungus Botrytis cinerea, and it ranged between 103.88 and 104.99 per 12 days. Statistical analyses revealed that virulence was not correlated with migration rate, but was negatively correlated with propagation rate on Botrytis cinerea, suggesting that the nematodes paid some cost for virulence. Also, there was no relationship between rates of migration and propagation. Cluster analysis showed that the biological parameters varied between crossbred lines, with no kinship bias, suggesting the absence of sex-linked inheritance in virulence and rates of propagation and migration.  相似文献   

16.
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   

17.
Microbial isolates from living petals, petal residues and leaf residues of rose, and from laboratory collections, were evaluated for control ofBotrytis cinerea in rose. In leaf residues artificially infested withB. cinerea, isolates of the filamentous fungiGliocladium roseum, FR136 (unidentified) andTrichoderma inhamatum reduced sporulation of the pathogen by >90%, other filamentous fungi were 25–90% effective, and those of yeasts and bacteria were <50% effective. In artificially inoculated petal residues, no microbe reduced sporulation ofB. cinerea by >75%, but isolates ofCladosporium oxysporum and four yeasts were 51–75% effective, and three filamentous fungi, eight yeasts andBacillus subtilis isolates were 26–50% effective. Isolates ofT. inhamatum, C. oxysporum andG. roseum performed best againstB. cinerea among isolates evaluated in leaf residues naturally infested with the pathogen and indigenous microorganisms. Totals of ten isolates of filamentous fungi (includingC. oxysporum andC. cladosporioides), two of yeasts and five ofBacillus subtilis completely prevented lesion production byB. cinerea in detached petals, and a further six isolates of filamentous fungi (includingG. roseum) and six yeasts were 90–99% effective. Isolates ofC. oxysporum, C. cladosporioides andB. subtilis, the most effective microorganisms againstB. cinerea in flower buds, reduced number of lesions in the range of 42–65% compared with 59–89% for à standard fungicide (vinclozolin). It is suggested that application of leading antagonists Jo living rose leaves and flowers should optimize control of inoculum production byB. cinerea when the tissues die. Optimal biocontrol of lesion production in flower buds requires a better understanding of the microenvironment of petals.  相似文献   

18.
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19.
Seventeen field isolates of Botrytis cinerea were compared by determining their radial growth on synthetic media containing various amounts of 21 antifungal compounds. Twelve of these compounds were fungicides that are recommended for the control of Botrytis infections. There were marked differences between the isolates in their sensitivity to the compounds. Individual isolates displayed high levels of resistance to some of the fungicides, including benomyl, carbendazim, iprodione, thiabendazole, thiophanate-methyl, vinclozolin and zineb. The most potent growth inhibitors were benomyl and carbendazim (ED95 values for most isolates <0.1 μg fungicide ml?1 media), dichlofluanid, iprodione, nystatin, thiabendazole, thiophanatemethyl and vinclozolin (ED95 values for most isolates < 1.0 μg ml?1), and captan, chlorothalonil, dicloran and thiram (ED95 values for most isolates < 6.0 μg ml?1). Zineb was much less potent than the other recommended anti-Botrytis fungicides; it was no more effective than carboxin, dinocap and mancozeb (ED95 values for most isolates > 25 μg ml?1).  相似文献   

20.
Tomato and strawberry are the most important protected crops in Lebanon and are seriously affected by grey mould disease, caused by Botrytis cinerea. In the present study, the fungicide sensitivity assays revealed medium to high frequencies of B. cinerea isolates resistant to benzimidazoles, dicarboximides, and anilinopyrimidines on tomato and strawberry. Fludioxonil- and boscalid-resistant mutants were uncommonly found at generally low frequency on both crops. Resistance to fenhexamid was detected in only one site on tomato but in most sites on strawberry with high frequencies, and the occurrence of resistance to QoI fungicides was ascertained on both crops. The majority of the tested isolates (>90%) exhibited multiple fungicide resistance, and isolates resistant to the seven antibotrydial fungicide classes were detected on strawberry in three locations. A high level of resistance was shown by B. cinerea mutants resistant to boscalid, fenhexamid, and QoI fungicides, while two levels of moderate and high resistance to anilinopyrimidines were identified. Genetic analysis revealed point mutations in the target genes commonly associated with resistance in B. cinerea isolates, with all mutants resistant to dicarboximides, fenhexamid, boscalid, and QoI fungicides carrying single-nucleotide polymorphims in BcOS1 (I365S/N, Q369P, and N373S), Erg27 (F412V/I), SdhB (H272R/Y), and cytb (G143A) genes, respectively. The general incorrect use of fungicides has caused the development and spread of fungicide resistance as a widespread phenomenon on protected tomato and strawberry in Lebanon. The implementation of appropriate antiresistance strategies is highly recommended.  相似文献   

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