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Pathogenicity and potential capacity for producing mycotoxins by Fusarium sambucinum and Fusarium solani isolates derived from potato tubers
Leszek Lenc
Plant Breeding and Seed Science , 2011, DOI: 10.2478/v10129-011-0025-y
Abstract: Studies of potential abilities of F. sambucinum to produce trichothecenes was conducted on isolates previously confirmed as belonging to this species by PCR. In all cases, A positive result for the presence of Tri5 gene, coding the ability to synthesize these mycotoxins. There was no potential to synthesize trichothecenes by F. solani. Further analysis concerned the potential ability of F. sambucinum to produce group B trichothecenes (DON and NIV). No isolate gave the expected amplification product (282 bp for deoxynivalenol and 312 bp for nivalenol), which would indicate the potential for producing these mycotoxins. Studies have shown the ability to produce trichothecenes of group A. Analysis of the potential ability for the synthesis of enniatins by F. sambucinum showed that 91% of isolates gave of 332 bp amplification product, which proves them as potencial producers of these mycotoxins. There were significant differences in the pathogenicity of F. sambucinum and F. solani represented by the size of decay caused by these species. The rotten tissue area caused by F. sambucinum was about 10 times bigger than after inoculation by F. solani. Furthermore, isolates within the same species (F. sambucinum) showed diverse pathogenicity. It should be noted, however, that the concentration of mycotoxins does not depend on the size of rotten tissue of potato tubers. Isolate, which caused the most severe disease symptoms, produced low concentrations of mycotoxins.
Singh Gurvinder,Kaur Maninderjit,Chander Mohan
International Research Journal of Pharmacy , 2013,
Abstract: Benzimidazole is a heterocyclic aromatic organic compound. It is an important pharmacophore and a privileged structure in medicinal chemistry. Benzimidazole and its derivatives play an important role in medical field with large number of Pharmacological activities such as antimicrobial, antiviral, antidiabetic and anticancer activity. This review is summarized to know about the chemistry of different derivatives of benzimidazoles along with their biological actions such as antioxidant, antimicrobial, anthelmintic, analgesic, antiprotozoal, antiulcer, antiviral, anticancer, antihypertensive, antineoplastic, anti-inflammatory, antifungal and anticonvulsant activity.
Méthodes de mesure de l’age physiologique des tubercules semences de pomme de terre (Solanum tuberosum L.)  [PDF]
Delaplace P.,Fauconnier ML.,du Jardin P.
Biotechnologie, Agronomie, Société et Environnement , 2008,
Abstract: Assessment methods of physiological age of potato seed tuber (Solanum tuberosum L.). The study of potato tuber ageing possesses both fundamental and applied interests. Because of potential economical impacts, numerous attempts have been made to develop reliable biophysical, physiological or biochemical markers of physiological age of seed tubers intended for vegetative multiplication. At the present time, biophysical markers do not meet this objective, the obtained results being contradictory or not very transposable. Some physiological markers seem well-suited but they are not predictive. The biochemical studies often focus on potato tuber developmental process or are undertaken without accurate physiological reference frame. After defining the main concepts, this study synthesizes and critically evaluates the different methods used to assess physiological age. An integrated research strategy based on existing data is finally proposed to study potato tuber ageing.
Perspectives de production des semences de pomme de terre à partir de vitropropagation en Tunisie  [PDF]
Faten Rejeb Gharbi,Mohamed El Fahem
Biotechnologie, Agronomie, Société et Environnement , 2007,
Abstract: Prospects of the potato seed production from vitropropagation in Tunisia. The profitability of seed potato production in Tunisia has been evaluated at five different stages, as following: stage 1: in-vitro-propagation of plants. Stage 2: minitubers production under insect-proof greenhouse. The three other steps, are done in the field by successive muni-tubers in creases to obtain super-elite SE , class elite E and A class tubers. Stage 3: first field multiplication to get class SE seeds. Stage 4: second field multiplication to get class E seeds. Stage 5: third field multiplication to get class A seeds. The production cost for stages 1 and 2 was, respectively, 0,253 TND and 0,182 TND. For stages 3, 4 and 5 the profitability depended on the multiplication rate in the field; downgrading rate; production cost; selling price. On the other hand, it would appear that the intervention of Groupement Interprofessionnel des Légumes (GIL) was crucial to the production process of class SE , E and A seeds. The free of charge supply of minitubers, by GIL, to seed producers would make the production of class SE seeds profitable. While for classe E and A , however, the profitability was guaranteed only when the rate of multiplication was equal to or higher than six. Compared to imported class E or A seeds, local seeds was less competitive. Further more, the intervention of GIL made local E seed competitive for all producers while the local class A seeds was competitive in the case of producers who got a rate of multiplication higher than four.
Conditions de compétitivité des semences de pomme de terre produites en Tunisie  [PDF]
Gharbi FR.,El Fahem M.
Biotechnologie, Agronomie, Société et Environnement , 2004,
Abstract: Competitiveness conditions of seed potato production in Tunisia. This work is an economic survey of the potato seed production in Tunisia from imported Elite class. Potato seed production in the studied regions ensures an average gross margin of 1717 Tunisian Dinars (TND)/ha and an average profit of 825 TND/ha for an average yield of 19 t/ha. Average production cost is estimated to be around 296 TND/t. The cost price of the produced seed after storage depends among others on the status of the stoker (Groupement Interprofessionnel des Légumes GIL, or private), the selling price, storage cost and the crop season (rear season, primer or season). Storage cost is the main component of seed costs for the cropping season. Under present prices and production techniques, price of imported potato seeds is more competitive compared to that of the seeds produced in Tunisia for season crops whether it is for the case of a professional organism GILor for season and primer crop in the case of private producers. Privatisation of potato seed production is therefore not envisageable.
Amino compounds and benzimidazoles derived from trifluralin and flumetralin
Alvares, P. S. M.;Vandresen, F.;Schuquel, I. T. A.;Oliveira, C.M.A.;Silva, C. C.;
Revista latinoamericana de química , 2010,
Abstract: in this work, we describe the synthesis of the amino compounds (5a) and (5b), and the benzimidazoles (6a), (6b) and (6c). these amino compounds and the benzimidazoles were obtained by catalytic hydrogenation of two widely used pesticides - flumetralin (4a) and trifluralin (4b). the reactions described are simple to perform, and generate no chemical wastes. the structures of the compounds were determined through ms and nmr data.
The Synthesis of Dicationic Extended Bis-Benzimidazoles  [PDF]
Zhijan Kang,Christine C. Dykstra,David W. Boykin
Molecules , 2004, DOI: 10.3390/90300158
Abstract: The synthesis of extended dicationic bis-benzimidazoles starting from trans-1,2-bis(4-cyanophenyl)ethene and trans-1,2-bis(4-cyanophenyl)cyclopropane is reported. The target diamidines show significant in vitro activity against B. subtilis.
Genotypic Identification for Some Fusarium sambucinum Strains Isolated from Wheat in Upper Egypt  [cached]
Jamal S.M. Sabir
World Journal of Agricultural Sciences , 2006,
Abstract: Random amplified polymorphic DNA (RAPD) was used to study the genetic variations among strains from Fusarium sambucinum isolated from wheat in Upper Egypt. Using two different primer (V6 and M13), the used strains showed a high degree of similarities and a distinct RAPD patterns. The dendrogram that constructed based on M13 primers showed that, there is no correlation between isolation sources and clustering system for the studied strains.
A Fungal Symbiont of Plant-Roots Modulates Mycotoxin Gene Expression in the Pathogen Fusarium sambucinum  [PDF]
Youssef Ismail,Susan McCormick,Mohamed Hijri
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0017990
Abstract: Fusarium trichothecenes are fungal toxins that cause disease on infected plants and, more importantly, health problems for humans and animals that consume infected fruits or vegetables. Unfortunately, there are few methods for controlling mycotoxin production by fungal pathogens. In this study, we isolated and characterized sixteen Fusarium strains from naturally infected potato plants in the field. Pathogenicity tests were carried out in the greenhouse to evaluate the virulence of the strains on potato plants as well as their trichothecene production capacity, and the most aggressive strain was selected for further studies. This strain, identified as F. sambucinum, was used to determine if trichothecene gene expression was affected by the symbiotic Arbuscular mycorrhizal fungus (AMF) Glomus irregulare. AMF form symbioses with plant roots, in particular by improving their mineral nutrient uptake and protecting plants against soil-borne pathogens. We found that that G. irregulare significantly inhibits F. sambucinum growth. We also found, using RT-PCR assays to assess the relative expression of trichothecene genes, that in the presence of the AMF G. irregulare, F. sambucinum genes TRI5 and TRI6 were up-regulated, while TRI4, TRI13 and TRI101 were down-regulated. We conclude that AMF can modulate mycotoxin gene expression by a plant fungal pathogen. This previously undescribed effect may be an important mechanism for biological control and has fascinating implications for advancing our knowledge of plant-microbe interactions and controlling plant pathogens.
Les politiques urbaines en Tunisie  [cached]
Mustapha Ben Letaief
Métropoles , 2008,
Abstract: En Tunisie, l’action publique en matière d’aménagement urbain conna t des mutations sensibles dans un contexte qu’on pourrait assimiler aux transitions post-keynésiennes. En effet, en 1994, la population urbaine tunisienne représentait 5,4 millions soit 61% de l’ensemble de la population. En 2015, les villes tunisiennes regrouperaient 68,5% de la population totale environ. Cette croissance urbaine consommera l’équivalent de la moitié de l’espace urbain existant au milieu des années quatre-vingt-dix. Ainsi, les villes tunisiennes doivent faire face à des besoins nouveaux en matières d’aménagement de terrains urbains, de constructions de logements, d’infrastructure et d’équipement.En même temps, depuis le milieu des années quatre-vingts, face aux difficultés budgétaires engendrées par la rétraction de ses ressources, la crise du modèle keynésien de gestion publique étroitement lié à un certain fordisme périphérique et le retour en force des logiques libérales préconisant la réhabilitation des mécanismes de régulation par marché, le désengagement de l’Etat et la redistribution des r les entre secteur public et initiative privée, l’Etat tunisien a adopté une politique d’ajustement libéral et d’ouverture économique impliquant une insertion dans le mouvement de globalisation. La question de la politique urbaine s’inscrit, désormais, dans cette logique et se décline en une politique dite de mise à niveau des villes tunisiennes tout en cherchant un certain désengagement de l’Etat.La conjugaison de ces trois phénomènes, de forte croissance urbaine, de désengagement et d’insertion dans la globalisation économique a engendré une mutation des modes de gouvernance urbaine et des logiques qui les régissent et qui s’avèrent contradictoires et difficilement conciliables conjuguant culture autoritaire, démarche partenariale et faible décentralisation. Ce texte tente de dégager les lignes de force, les contradictions et les perspectives de l’action publique dans une période de transition post-keynésienne dans un pays dit émergent .

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