<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">MAÂTAOUI, M E L</style></author><author><style face="normal" font="default" size="100%">Espagnac, H</style></author><author><style face="normal" font="default" size="100%">MICHAUX-FERRIÈRE, N</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Histology of Callogenesis and Somatic Embryogenesis Induced in Stem Fragments of Cork Oak (Quercus suber) Cultured In Vitro</style></title><secondary-title><style face="normal" font="default" size="100%">Annals of Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">callogenesis</style></keyword><keyword><style  face="normal" font="default" size="100%">cork-oak</style></keyword><keyword><style  face="normal" font="default" size="100%">embryogenic cells</style></keyword><keyword><style  face="normal" font="default" size="100%">histology</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber L.</style></keyword><keyword><style  face="normal" font="default" size="100%">secondary embryogenesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Somatic embryogenesis</style></keyword><keyword><style  face="normal" font="default" size="100%">starch</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1990</style></year></dates><volume><style face="normal" font="default" size="100%">66</style></volume><pages><style face="normal" font="default" size="100%">183-190</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Calluses able to produce somatic embryos were formed during in vitro culture of shoot fragments of cork oak (Quercus suber L.).Histological monitoring of these fragments during culture showed that it was the cortical parenchyma cells which underwent dedifferentiation before calluses were formed by repeated divisions. The calluses consisted of parenchyma cells surrounded by a few layers of meristematic cells. Proembryos formed in groups around the edge of some calluses. Histological examination showed that they were produced by the evolution of two different categories of cell: one category had the appearance of ‘embryogenic’ cells with very thick walls, a small vacuole rich in starch and a well-developed nucleus with a prominent nucleolus. The other cells were very bulky with large vacuoles; their morphology was similar to that of suspensor cells encountered in embryogenesis in gymnosperms. The ontogenic stages were similar to those described in zygotic embryos of the genus Quercus. Nevertheless, most of the embryonic structures deviated from normal development and at all stages produced secondary proembryos.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">ELMAATAOUI, M</style></author><author><style face="normal" font="default" size="100%">Espagnac, H</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">NEOFORMATION OF SOMATIC EMBRYOS-LIKE STRUCTURES FROM CORK-OAK (QUERCUS-SUBER L) TISSUE-CULTURES</style></title><secondary-title><style face="normal" font="default" size="100%">COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE III-SCIENCES DE LA VIE-LIFE SCIENCES</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1987</style></year></dates><publisher><style face="normal" font="default" size="100%">JOHN LIBBEY EUROTEXT LTD</style></publisher><pub-location><style face="normal" font="default" size="100%">127 AVE DE LA REPUBLIQUE, 92120 MONTROUGE, FRANCE</style></pub-location><volume><style face="normal" font="default" size="100%">304</style></volume><pages><style face="normal" font="default" size="100%">83--&amp;</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Embryoid-like formations were induced on cork-oak (Quercus suber L.) calluses grown in vitro on Murashige and Skoog's médium, supplemented with IBA and BAP. Thèse formations rapidly differenciated an apical meristem, flanked with two cotylédons, and a radicular meristem on the opposite end. In most cases embryoids' development stopped there, as if meristems became dormant immediately after their organization. But under certain culture conditions these somatic embryos can produce a great number of secondary embryoids. This multiplication capacity seems to be maintained over generations</style></abstract></record></records></xml>