Relationship between epistasis and aggressiveness in resistance of pepper (Capsicum annuum L.) to Phytophthora nicotianae

This study evaluated the types of gene action governing the inheritance of resistance to Phytophthora nicotianae necrosis in populations derived from two crosses involving two susceptible (Beldi and Nabeul II) and one resistant (CM334) cultivars of pepper (Capsicum annuum L.). Populations, composed of Pr, Ps, F1 , F 2 , BC 1 Pr, and BC 1 Ps generations, were inoculated with six P. nicotianae isolates. Generation means analysis indicated that an additive-dominance model was appropriate for P. nicotianae isolates Pn Ko1 , Pn Ko2 and Pn Kr1 , which showed low aggressiveness in the two crosses. For the more aggressive isolates Pn Bz1 , Pn Bz2 and Pn Kr2 , epistasis was an integral component of resistance in the two crosses. The presence of epistasis in the resistance of pepper to P. nicotianae was dependent on the level of aggressiveness of the isolates. Selection in pepper with less aggressive isolates was efficient, but not with more aggressive isolates; on the other hand, selection with more aggressive isolates was more stable. The minimum number of genes controlling resistance was estimated at up to 2.71. In the majority of cases, the additive variance was significant and greater than the environmental and dominance variance

Antifungal activity and chemical composition of seven essential oils to control the main seedborne fungi of cucurbits

none9siEssential oils represent novel alternatives to application of synthetic fungicides to control against seedborne pathogens. This study investigated seven essential oils for in vitro growth inhibition of the main seedborne pathogens of cucurbits. Cymbopogon citratus essential oil completely inhibited mycelial growth of Stagonosporopsis cucurbitacearum and Alternaria alternata at 0.6 and 0.9 mg/mL, respectively. At 1 mg/mL, Lavandula dentata, Lavandula hybrida, Melaleuca alternifolia, Laurus nobilis, and two Origanum majorana essential oils inhibited mycelia growth of A. alternata by 54%, 71%, 68%, 36%, 90%, and 74%, respectively. S. cucurbitacearum mycelia growth was more sensitive to Lavandula essential oils, with inhibition of ~74% at 1 mg/mL. To determine the main compounds in these essential oils that might be responsible for this antifungal activity, they were analyzed by gas chromatography–mass spectrometry (GC-MS). C. citratus essential oil showed cirtal as its main constituent, while L. dentata and L. nobilis essential oils showed eucalyptol. The M. alternifolia and two O. majorana essential oils had terpinen-4-ol as the major constituent, while for L. hybrida essential oil, this was linalool. Thus, in vitro, these essential oils can inhibit the main seedborne fungi of cucurbits, with future in vivo studies now needed to confirm these activities.openMoumni M.; Romanazzi G.; Najar B.; Pistelli L.; Amara H.B.; Mezrioui K.; Karous O.; Chaieb I.; Allagui M.B.Moumni, M.; Romanazzi, G.; Najar, B.; Pistelli, L.; Amara, H. B.; Mezrioui, K.; Karous, O.; Chaieb, I.; Allagui, M. B

Facebook's Mobile Career

At the end of its first decade, Facebook’s identity, popularity, and characteristics are shaped in important ways by its becoming a form of mobile media, as much as it as platform associated with Internet and social media. This paper seeks to explore and understand Facebook as the important force in mobile media and communication it now is. It draws upon and combines perspectives from technology production, design, and economy, as well as user adoption, consumption, practices, affect, emotion, and resistance. The paper discusses the beginnings of mobile Facebook, and the early adoption of mobile Facebook associated with the rise of smartphones. The second part of the paper explores Facebook’s integration with photography (with Instagram) and social games (such as Zynga’s Farmville). The paper argues that Facebook’s mobile career is an accomplishment that has distinctively melded evolving affordances, everyday use across a wide range of settings, as well as political economies, corporate strategy, and design.Australian Research Counci

Wikipedia Arabe et la construction collective du savoir (Wikipedia Arabic and the collective construction of knowledge)

Cette recherche part du constat d’une faible participation à, et d’un maigre contenu dans Wikipedia Arabe et questionne les obstacles à un contenu plus riche. La problématique de la recherche est double: d’abord proposer une cartographie numérique de Wikipedia dans la région du Moyen-Orient et Afrique du Nord. Cette cartographie informe d’une part sur la représentation des participants à Wikipedia Arabe, et d’autre part, sur la contribution à la distribution du savoir arabe et de son étendue. Deuxièmement, la recherche s’intéresse au contenu de Wikipedia arabe et de son mode de production. Plus particulièrement, les questions de recherche portent sur la participation à la production de contenu de Wikipedia Arabe, les barrières à l’entrée dans Wikipedia Arabe, les dynamiques de négociation et de consensus entre éditeurs et administrateurs Wikipediens de la région et les solutions envisagées pour améliorer et encourager la production de contenu. La démarche méthodologique est principalement qualitative.So far Arabic content on Wikipedia Arabic is very weak; this paper questions the barriers that prevent contributors to Wikipedia Arabic from being more active in content production on Wikipedia Arabic. The research problematic is twofold: first, it suggests a digital cartography of Wikipedia in the MENA region that informs about those who represent Wikipedia Arabic and thus, contribute to the Arab knowledge distribution. Second, while adopting a qualitative approach, the research looks at the content of Arabic Wikipedia. It questions its production methods, contribution barriers, dynamics of negotiation between Wikipedians, and strategies of consensus between editors and admins, as well as the envisioned solutions to improve and promote Wikipedia Arabic content production.</p

Wikipedia Arabe et la construction collective du savoir (Wikipedia Arabic and the collective construction of knowledge)

Cette recherche part du constat d’une faible participation à, et d’un maigre contenu dans Wikipedia Arabe et questionne les obstacles à un contenu plus riche. La problématique de la recherche est double: d’abord proposer une cartographie numérique de Wikipedia dans la région du Moyen-Orient et Afrique du Nord. Cette cartographie informe d’une part sur la représentation des participants à Wikipedia Arabe, et d’autre part, sur la contribution à la distribution du savoir arabe et de son étendue. Deuxièmement, la recherche s’intéresse au contenu de Wikipedia arabe et de son mode de production. Plus particulièrement, les questions de recherche portent sur la participation à la production de contenu de Wikipedia Arabe, les barrières à l’entrée dans Wikipedia Arabe, les dynamiques de négociation et de consensus entre éditeurs et administrateurs Wikipediens de la région et les solutions envisagées pour améliorer et encourager la production de contenu. La démarche méthodologique est principalement qualitative.So far Arabic content on Wikipedia Arabic is very weak; this paper questions the barriers that prevent contributors to Wikipedia Arabic from being more active in content production on Wikipedia Arabic. The research problematic is twofold: first, it suggests a digital cartography of Wikipedia in the MENA region that informs about those who represent Wikipedia Arabic and thus, contribute to the Arab knowledge distribution. Second, while adopting a qualitative approach, the research looks at the content of Arabic Wikipedia. It questions its production methods, contribution barriers, dynamics of negotiation between Wikipedians, and strategies of consensus between editors and admins, as well as the envisioned solutions to improve and promote Wikipedia Arabic content production.</p