Botrytis cinerea and its Resistance to Dicarboximide Fungicides1

In all vineyards in the Pfalz area (FRG) where the dicarboximide fungicides have been applied, resistant isolates can nowadays be found. These do not differ from the sensitive ones in uptake of the active ingredient of the dicarboximides or in the number of nuclei in spores or hyphal cells. The percentage of resistant strains decreases in the population when there is a long gap between applications of the fungicides. As a possible explanation, we have observed tendencies to resensitization in all resistant isolates. The degree of resensitization varies according to isolate.     

Effects of certain herbicides on the fate of sporangiospores of Mucor piriformis and conidia of Botrytis cinerea and Penicillium expansum

The effects of several herbicides used in pome fruit orchards on the germination of spores and growth of mycelia of Botrytis cinerea, Mucor piriformis and Penicillium expansum in vitro and the survival of propagules of these fungi in soil were studied. Diuron in agar at 4–128 μg ml^?1 reduced germination of spores of B. cinerea and M. piriformis, and 2,4-D and paraquat at 32 μg ml^?1 similarly affected B. cinerea and P. expansum. Several herbicides at 128 μg ml^?1 in agar reduced growth of B. cinerea and M. piriformis but were ineffective against P. expansum. Propagule survival levels of the three fungi generally were lower in both autoclaved and non-autoclaved soil amended with herbicides than in non-amended soil. This effect was greatest in non-autoclaved soil, suggesting involvement of microbial antagonists. The most effective herbicides for reduction of fungal propagules in soil were 2,4-D, diuron, and paraquat.     

Chemical Control of Botrytis cinerea on Grapes in New York (USA)1

Control of gray mold in New York vineyards is difficult to achieve at the present time. Benomyl-resistant strains of Botrytis cinerea have been isolated from vineyards in all grape-growing regions of New York State. Because of this resistance and lack of governmental registration of new fungicides, growers must choose among only moderately effective fungicides such as captan, folpet, dicloran and copper. Current research indicates that either vinclozolin or iprodione at 850 g/ha to 1100 g/ha applied twice, beginning at about 5 % sugar content and two weeks later, will provide excellent control of gray mold on ripening berries, whereas sprays applied at 5 % or 90 % bloom and at berry touch are not effective. An application of gibberellic acid (GA3) (10 or 25 (µg/ml) on Aurore (S.5279) at 10–15 cm shoot growth reduced the severity of gray mold on clusters of ripe fruit, but not the incidence of it. A single application of triadimefon at 30 mg/1 sprayed on Vignoles (Ravat 51), when fruit clusters averaged 17 % surface area infected with Uncinula necator and 2.6 % sugar content, retarded the development of powdery mildew and subsequent berry splitting, and ultimately reduced the severity of gray mold by 50 % at harvest, 6 weeks later.     

Antifungal Activity of 2-Deoxy-D-Glucose on Botrytis cinerea, Penicillium expansum, and Rhizopus stolonifer: Ultrastructural and Cytochemical Aspects

ABSTRACT The effect of 2-deoxy-D-glucose on major postharvest pathogens was investigated at the ultrastructural and cytochemical level. Hyphae of Botrytis cinerea, Penicillium expansum,, and Rhizopus stolonifer grown in the absence of 2-deoxy-D-glucose were normal and showed no apparent cytological alterations. In the presence of 2-deoxy-D-glucose, however, these fungi exhibited severe cellular injuries ranging from cell wall disruption to cytoplasm disintegration. Although 2-deoxy-D-glucose caused cytoplasmic degeneration in the three fungi tested, cell wall alterations were exhibited only by B. cinerea and R. stolonifer. In the latter, the retraction of degenerated cytoplasm was often accompanied by the deposition of amorphous material in paramural spaces. Cytochemical study of fungal cell wall components showed that 2-deoxy-D-glucose caused a marked increase of chitin- and beta-1,3-glucan-labeling in R. stolonifer and B. cinerea, indicating an interference of 2-deoxy-D-glucose with fungal wall biosynthesis. The observed cellular alterations indicate that 2-deoxy-D-glucose may also have affected other metabolic processes.     

Relations entre le desséchement de la rafle et Botrytis cinerea sur raisins1

Le dessèchement de la rafle d' origine physiologique et la pourriture pédonculaire due au champignon Botrytis cinerea sont encore trés souvent confondus par les praticiens et techniciens. De ce fait, les differences et analogies dans les symptomes sont discutees. Le dessèchement de la rafle est surtout caractérisé par la date d' apparition des atteintes, dans les 15 jours qui suivent la mi-véraison, et par la présence de nécroses bien localisées, sèches, a contours limites. De nombreux facteurs sont communs. Mais, contrairement à l' opinion encore très répandue, le dessèchement de la rafle ne favorise pas l' installation de B. cinerea. Certaines techniques, telles que l' effeuillage, le traitement a la gibbérelline, l' enlèvement de baies, réduisent les deux maladies. On constate alors un enrichissement en calcium et magnésium de la rafle qui s'accompagne d' un développement des faisceaux libéro-ligneux dans le cas de la gibbérelline. L' importance économique de la pourriture pédonculaire est plus grande; les pertes peuvent s'elever jusqu'a 50–60 % de la récolte contre moins de 25 % par le dessèchement de la rafle. Le traitement des grappes à la véraison, avec un mélange d' un sei magnésien et d' un fongicide de la famille des imides cycliques, est efficace.     

Biological evidence for a 1:1 Ca2+:glyphosate association in deposit residuals on the leaf surface of barley

It has long been known that calcium ion antagonizes glyphosate, but it was not clear whether the stoichiometry of their interaction is 1:1 or 1:2. Two independent methods were used to determine which stoichiometry was the most probable. First, dose–response curves of barley ( Hordeum vulgare L.) plants treated with glyphosate were determined in the presence of 0, 1.25, 2.5, 5 and 10 mM CaCl₂. The doses of 'free' glyphosate (=not inactivated by calcium ion) were computed using the assumptions of 1:1 and 1:2 stoechiometries. The response curves were redrawn as a function of 'free' glyphosate. Analysis showed that the 1:2 hypothesis could be rejected, whereas the 1:1 hypothesis was highly probable. Second, kinetics of glyphosate penetration into barley leaves were determined in the presence of 0, 2.5 and 10 mM CaCl₂. The concentrations of 'free' glyphosate were computed as above. The kinetics of glyphosate penetration at these concentrations were established and were compared to the kinetics of glyphosate penetration in the presence of CaCl₂. Again, the 1:2 hypothesis was rejected, whereas the 1:1 hypothesis was more probable. These results strongly suggest that the stoichiometry of the Ca²⁺:glyphosate association is 1:1 in deposit residuals on the leaf surface.     

Observations sur les effets de Botrytis cinerea au cours de travaux de sélection de la vigne1

Des observations faites au cours des travaux de sélection sur des descendances issues de semis ont permis de mettre en évidence des liaisons positives entre l'intensité de la pourriture et chacun des critères: « puissance >> des souches et degré alcoolique probable du moút. Ces observations qui étaient recueillies sous forme de notations ont été analysées en recourant au coefficient de corrélation de Spearman. La liaison constatée entre le degré alcoolique et l'intensité de la pourriture n'est pas d'une interprétation facile.     

The Use of a Radioimmunosorbent Assay for Botrytis cinerea1

A radioimmunosorbent assay was developed for Botrytis cinerea which can be used to detect as little as 100 ng of Botrytis mycelium (dry weight). Of 22 fungi tested in the assay, all significant reaction was restricted to members of the Sclerotiniaceae. No reaction was obtained with representative isolates of Aspergillus, Alternaria or Peiticillium. Other Botrytis species gave the most reaction relative to B. cinerea. and related genera such as Monilinia and Sclerotinia yielded small reactions. The assay can be used to detect fi. cinerea infection of grape berries when as little as 0.1 % of homogenate from infected fruit is mixed with homogenate from sound fruit to simulate a minor infection. The assay of free run juice from various lots of grapes was highly correlated with visual assessments of infection in the field. Pursuant to various theories concerning bloom time infection, the assay was used to analyse the B. cinerea content of immature berry tips and floral debris; however, no evidence of such colonization was obtained.     

Induction of Resistance to Penicillium digitatum in Grapefruit by the Yeast Biocontrol Agent Candida oleophila

ABSTRACT The yeast Candida oleophila, the base of the commercial product Aspire, is recommended for the control of postharvest decay in citrus and pome fruit. Its modes of action include nutrient competition, site exclusion, and direct mycoparasitism. In the present study, we showed that application of Candida oleophila to surface wounds or to intact 'Marsh Seedless' grapefruit elicited systemic resistance against Penicillium digitatum, the main postharvest pathogen of citrus fruit. The induction of pathogen resistance in fruit was already pronounced 24 h after elicitation; it was distance, concentration, and time dependent and restricted to the peel tissue closely surrounding the yeast application site. The induction of pathogen resistance required viable yeast cells at concentrations of 10(8) to 10(9) cells ml(-1). Nonviable autoclaved or boiled yeast cells or lower yeast concentrations were ineffective in enhancing fruit disease resistance. Application of Candida oleophila cell suspensions to grapefruit peel tissue increased ethylene biosynthesis, phenylalanine ammonia lyase activity, and phytoalexin accumulation, and increased chitinase and beta-1,3-endoglucanase protein levels, indicated by western immunoblotting analysis. Scanning electron microscope observations revealed that spore germination and germ tube growth of Penicillium digitatum were markedly inhibited in wounds made near the yeast-treated sites. Overall, this study provides evidence that induced resistance against postharvest decay of citrus fruit should be considered an important component of the multiple modes of action of the yeast Candida oleophila.     

Pectolytic and Cellulolytic Enzymes of Dicarboximide-sensitive and Resistant Strains of Botrytis cinerea1

Starting in 1979 the pathogenicity of dicarboximide-resistant and sensitive strains of Botrytis cinerea was regularly examined in greenhouse tests using grape plants. In these tests the proportion of resistant strains with low or nearly no pathogenicity was always higher than that of sensitive strains. This led to comparative studies on the enzyme activities of sensitive and resistant field isolates. Pectolytic and cellulolytic enzymes were chosen because of their importance in the infection process of B. cinerea. The results of these studies indicated that no correlation could be found between the activity of these enzymes and the pathogenicity of the tested isolates, and that resistant strains tended to have higher enzyme activities than sensitive ones. Comparison of the enzyme activities of laboratory-adapted isolates and the original sensitive ones gave similar results. Since enzyme activities do not seem to play an important role in explaining the general observations on the slow increase and spread of resistant strains in vineyards, other factors must be considered, such as the stability of the dicarboximide resistance, which apparently is very low.     

La protection du vignoble contre Botrytis cinerea en Italie du Nord et du Centre. Situation actuelle et perspectives d'avenir1

Les infections dues à Botrytis cinerea entraînent des pertes variables, mais souvent considérables. La diversité de la conformation orographique et la variabilityé climatique de chaque zone viticole qui en découle, d'une part, et la diversité des cépages, d'autre part, rendent difficile la mise en place d'un service central d'avertissement. La préférence est par conséquent donnée à la méthode de protection qui repose sur trois traitements appliques en fonction des stades phénologiques. Les viticulteurs les plus avertis sont cependant en mesure de combiner cette méthode rigide avec celle plus logique qui se base sur l'évolution des données météorologiques. Pour les cépages les plus sensibles et de haute qualityé, le programme de traitement contre B. cinerea est réalisé a l'aide de la vinchlozoline, qui permet d'obtenir des indices de protection de l'ordre de 80–90 %. Après six ans d'application des imides cycliques sur les mêmes vignobles expérimentaux, on n'a pas observé l'apparition de souches de B. cinerea résistantes à ces fongicides. Une expérimentation en cours est destinée à réduire le potentiel de l'inoculum hivernant, et examine les possibilityés de stopper une épidémie. Elle porte, de plus, sur l'emploi de mélanges de produits et sur l'alternance de ceux-ci. Des perspectives intéressantes s'ouvrent par l'emploi d'antagonistes microbiens et par l'amélioration génétique.     

Movement of fluometuron, simazine, 36Cl− and 144Ce3+ in soil under field conditions: qualitative aspects

The distributions of two herbicides and two radioactive ions in field plots at two sites were determined at periods up to 187 days following surface applications in the spring. The results demonstrated the variability characteristic of field situations. At one site some fluometuron moved a short distance down the profile but after 187 days most remained above 6 cm whereas at the other site there was essentially no movement below 3 cm. At both sites simazine was almost entirely confined to the top 3 cm. The adsorption characteristics of the two compounds are similar so the greater mobility of fluometuron is probably a consequence of its greater solubility, Measurements of ³⁶Cl^? indicated a significant movement of water through the 30 cm depth studied. ¹⁴⁴Ce³⁺ used as a tracer of soil particles was of similar mobility to simazine. In general the movement of chloride and the two herbicides can be interpreted in terms of the concept of mobile and immobile fractions of soil water in which a proportion of the mobile water does not reach equilibrium with solutes in the bulk of the soil. Soil structural effects may therefore be more important than adsorption in controlling the movement of solutes and redistribution in association with soil particles can be significant. A parallel laboratory experiment showed that the results from a standard leaching column procedure did not necessarily indicate field performance.     

Use of Mixture or Alternation of Fungicides with the Aim of Reducing the Risk of Appearance of Strains of Botrytis cinerea Resistant to Dicarboximides1

Results are reported for four experimental trials carried out against Botrytis cinerea on wine grapes in Piedmont (Northern Italy) during 1979 and 1980, using fungicides with different mechanisms of action, alternately or in mixture. Good effectiveness was obtained not only with the exclusive use of dicarboximide fungicides but also with alternated spray programmes, for example using benomyl or captafol or dichlofluanid for the first two sprays and the dicarboximides only for the last two sprays. It was possible to reduce the number of sprays with the dicarboximides to only one (at beginning of ripening), by, for example, alternating dichlofluanid, vinclozolin and benomyl. Good results were also obtained using half-rate mixtures of fungicides with different mechanisms of action, for example benomyl or dichlofluanid mixed with one of the dicarboximides. In this way the selection pressure exercised by the dicarboximides is decreased. Moreover, the cost of treatments is reduced owing to the lower price of benomyl, dichlofluanid and captafol and because these fungicides are effective not only against B. cinerea but also against powdery mildew (benomyl) or downy mildew (dichlofluanid and captafol).     

不同浓度铁离子对黄芩抗氧化酶活性等生理特性的影响

对不同浓度铁离子处理下黄芩抗氧化酶活性等生理特性进行了研究,结果表明:M4处理(Fe2+浓度为6.95 mg/kg)下黄芩的株高最高,其叶绿素含量、SOD酶活性、POD活性、可溶性蛋白质含量均显著高于其他处理,而其丙二醛含量却显著低于其他处理。研究结果提示,Fe2+浓度为6.95 mg/kg可有效增强黄芩细胞活性,促进黄芩生长,是黄芩生长的最佳铁离子浓度。     

Développement des souches de Botrytis cinerea résistantes aux dicarboximides dans les vignes de la Suisse alémanique1

Pour tester la résistance aux dicarboximides (imides cycliques) des souches prélevées en plein champ, les spores sont appliquees sur des disques d'agar placés à l'envers sur des milieux nutritifs contenant les différentes concentrations du fongicide. L'évaluation est faite 4 à 5 jours après le début de l'essai afin d'exclure les souches susceptibles de s'adapter après quelques jours de contact à la matiere active en laboratoire. En 1979, on a isolé pour la première fois, à partir de prélèvements de plein champ, des souches tolérantes à l ou 3 ppm de matière active. Une augmentation du nombre de souches résistantes a été constatèe en 1980. La croissance du mycélium et la germination des spores sont inhibées à peu prés de la meme manière. Les souches résistantes ne montrent pas de diminution de vigueur de Finfection sur pommes. L'efficacité de la lutte anti-botrytis n'est pas encore diminuee dans les parcelles qui ont un grand pourcentage de souches résistantes.     

镉对紫花苜蓿种子萌发等生理特性的影响

以阿尔冈金(Algonquin)和新疆大叶(M.sativa L.cv.xinjiangdaye)种子为试验材料,研究了0～5mg/L浓度的Cd2 处理对其种子生理特性的影响.结果表明:低浓度和高浓度的Cd2 对二者种子的发芽势和发芽率均有抑制作用,而中同浓度却有促进作用,呈现"下降-回升-下降"的现象;发芽指数和活力指数.均随着Cd2 浓度的增大而下降;与对照相比,随Cd2 处理浓度的增大,阿尔冈金和新疆大叶的下胚轴、根长、苗长、地上部分鲜重、地下部分鲜重都随之降低,但新疆大叶降低的幅度更大一些;随着Cd2 处理浓度的升高,阿尔冈金和新疆大叶的脯氨酸、电解质泄漏率、丙二醛(MDA)含量都随之增大;但在同浓度的Cd2 处理下:幼苗叶片中的脯氨酸含量:新疆大叶＞阿尔冈金;电解质泄漏率:新疆大叶＜阿尔冈金;丙二醛(MDA):新疆大叶＜阿尔冈金.试验表明,优良牧草紫花苜蓿的两个品种中,阿尔冈金对Cd2 胁迫的耐受能力要强于新疆大叶.     

Synthesis of 2-amino-6-oxocyclohexenylsulfonamides and their activity against Botrytis cinerea

BACKGROUND: With the objective of exploring the fungicidal activity of 2‐oxocyclohexylsulfonamides (2), a series of novel 2‐amino‐6‐oxocyclohexenylsulfonamides (6 to 23) were synthesised, and their fungicidal activities against Botrytis cinerea Pers. were evaluated in vitro and in vivo. RESULTS: The compounds were characterised by IR, ¹H NMR and elemental analysis. Bioassay results of mycelial growth showed that compounds 6 to 23 had a moderate antifungal activity against B. cinerea. N‐(2‐methylphenyl)‐2‐(2‐methylphenylamino)‐4,4‐dimethyl‐6‐oxocyclohexenylsulfonamide (13) and N‐(2‐chlorophenyl)‐2‐(2‐chlorophenylamino)‐6‐oxocyclohexenylsulfonamide (21) showed best antifungal activities, with EC₅₀ values of 8.05 and 10.56 µg mL^?1 respectively. Commercial fungicide procymidone provided an EC₅₀ value of 0.63 µg mL^?1. The conidial germination assay showed that most of compounds 6 to 23 possessed excellent inhibition of spore germination and germ‐tube elongation of conidia of B. cinerea. For in vivo control of B. cinerea colonising cucumber leaves, the compound N‐cyclohexyl‐2‐(cyclohexylamino)‐4,4‐dimethyl‐6‐oxocyclohexenylsulfonamide (19) showed a better control effect than the commercial fungicide procymidone. CONCLUSION: The present work demonstrated that 2‐amino‐6‐oxocyclohexenylsulfonamides can be used as possible new lead compounds for further developing novel fungicides against B. cinerea. Copyright © 2011 Society of Chemical Industry     

La résistance de Botrytis cinerea aux benzimidazoles et aux imides cycliques: situation dans les vignobles alsaciens, bordelais et champenois1

Dans les vignobles alsaciens, bordelais et champenois des experimentations sont entreprises pour suivre l'évolution des phénomènes de résistance de Botrytis cinerea aux fongicides. Dans le cas des benzimidazoles (bénomyl, carbendazime, méthylthio-phanate), toutes les souches présentent un haut niveau de résistance et en 1980 leur fréquence moyenne était de 63 %. Ceci implique que le réemploi des benzimidazoles est improbable dans un proche avenir. Avec les imides cycliques (iprodione, procymidone et vinchlozoline) la situation est moins critique car il n'y a pas d'inefficacité notoire, bien que des souches résistantes soient présentes dans la nature. Ceci peut s'expliquer par le fait que les niveaux de résistance sont bas; cependant des souches hautement résistantes sont décelées et dans l'avenir il faudra surveiller leur évolution.     

辣椒碱对小菜蛾体内谷胱甘肽S-转移酶和Na+ -K+ -ATP酶活性的影响

采用常规生化方法测定了辣椒碱对小菜蛾体内谷胱甘肽S-转移酶和Na+ -K+ -ATP酶活性的影响。结果表明,经不同浓度辣椒碱处理12 h后,小菜蛾体内谷胱甘肽S-转移酶活力均显著低于空白对照,在100.56~141.53 μmol ·L-1 ·mg-1Pro ·min-1 之间;而Na+ -K+ -ATP酶活力均显著高于空白对照,在12.43~20.36 μmol ·mg-1Pro ·min-1之间。说明辣椒碱能抑制小菜蛾体内谷胱甘肽S-转移酶的活性,而对Na+ -K+ -ATP酶活性则表现为促进作用。