LLORET, P. G., and PULGAR~N, A. 1992. Effect of naphthaleneacetic acid on the formation of lateral roots in the adventitious root of Allium cepa: number and arrangement of laterals along the parent root. Can. J. Bot. 70: 1891 -1896.The exogenous application of an auxin (a-naphthaleneacetic acid) to the adventitious root of Alliuln cepa L. promotes lateral root formation and inhibits main root elongation. If the adventitious roots are released from the influence of this auxin, they may resume elongation after M but not after treatment. Auxin leads to the appearance of late-forming root primordia intercalated between previously formed laterals. The arrangement of laterals along the adventitious root is another feature altered by treatment, i.e., control roots develop the same number of laterals throughout the length of the zone in which laterals appear, whereas in treated roots the number of laterals rises steadily as the distal end of this zone is approached. In M auxin-treated roots, no increase in the number of laterals occurs in basal zones of the parent root, whereas treatment with 10-I M naphthaleneacetic acid leads to a sharp rise in the number of laterals formed at these zones. Our results suggest that the basal part of onion roots is less sensitive than the apical portion of the effects of naphthaleneacetic acid. This chemical seems to have a rejuvenating effect on cells of the pericycle, enabling them to initiate lateral primordia when under normal conditions they would no do so.Key words: Allium cepa, auxin, lateral root, naphthaleneacetic acid, onion. LLORET, P. G., et PULGAR~N, A. 1992. Effect of naphthaleneacetic acid on the formation of lateral roots in the adventitious root of Allium cepa: number and arrangement of laterals along the parent root. Can. J. Bot. 70 : 1891 -1896.L'addition d'une auxine exogkne (acide a-naphtalkne acCtique) aux racines adventives de 1'Allium cepa L. stimule la formation de racines lattrales et inhibe l'tlongation de la racine principale. Si les racines adventives sont soustraites B l'influence de cette auxine, elles peuvent reprendre leur Clongation aprks des traitements B M mais non B M. L'auxine conduit B l'apparition de primordiums racinaires B formation tardive intercallts entre les racir~es laterales dkji formtes. L'arrangement des racines lattrales le long de la racine adventive est une autre caractCristique affectCe par le traitement, i.e., les racines ttmoins dCveloppent le m&me nombre de racines lattrales tout au long de la zone dans laquelle les racines 1atCrales apparaissent, alors que chez le racines traittes, le nombre des racines lattrales augmente continuellement B mesure qu'on approche de l'extrtmitt distale de cette zone. Chez les racines traitCes avec M d'auxine, il n'y a pas d'augmentation dans le nombre de racines lattrales dans les zones basales de la racine mere, alors que le traitement B l'acide naphtalene acktique M conduit B une nette augmentation du nombre de racines latkrales formtes sur ces zones. Les rtsultats indiquent que la portion basale ...
The objective of this study was to make a current diagnosis of the scientific production of Ibero-American researchers on information literacy and information competences during the last four decades. The literature output on information literacy was examined using the techniques of bibliometric analysis and information visualization. The literature considered was that constituted by the articles included in the Web of Science (Thomson Reuters), Scopus (Elsevier), Library and Information Science Abstracts, and Library, Information Science and Technology Abstracts databases. The occurrence of descriptors was analysed using VOSViewer, a program that groups them into clusters and generates a map of their connections. The results showed exponential growth of some 30 % annually between 2005 and 2011, with a mean of 14.45 documents per year. Spain, with 119 documents, was the top producing country, followed by Brazil with 76. The distribution of the more than 500 authors fitted a Lotka-law pattern, and the distribution of the 105 journals fitted the three zones of a Bradford-law pattern. The visualization map showed the 62 descriptors to group into seven clusters. For its centrality, there stood out ''Information literacy'', strongly related with ''Information Science''. At the edge of the
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