Morphogénèse des systèmes racinaires des semis et boutures de chêne pédonculè

摘要: Primary roots are orthogeotropic on seedlings (Fig. 3) and cuttings taken from 23 to 25) semi-plagiogeotropic sprouts old stumps. 6–8–10). And when these decapitated, they regenerate generally with the same geotropism 5 11). These properties cannot be easily changed. Several years after rooting, primary of stumps still 14–15 21). Orthogeotropism can considered as a juvenile character. Growth lateral under control tip root. When longitudinal growth main root is blocked 16) become longer thicker acquire But only reduced 1 2) or taproot regenerates new continuously 17) secundary may but remain sub- horizontal. A shallow watertable clay soil blocks increases porosity all 19). Geotropism given seems depend lower order, tissue (cutting seedlings, stumps, cutting…) perhaps also shoot. Up now we could not obtain systematically cutting Some observations however suggests that this might impossible.