<?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%">MANSOUR, A.</style></author><author><style face="normal" font="default" size="100%">de FAŸ, E.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Rhythmic growth rings of wood and their relationship with the foliage in oak seedlings grown in a favourable environment</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%">allometric relationship</style></keyword><keyword><style  face="normal" font="default" size="100%">juvenile wood</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf area</style></keyword><keyword><style  face="normal" font="default" size="100%">lignification</style></keyword><keyword><style  face="normal" font="default" size="100%">oak seedling</style></keyword><keyword><style  face="normal" font="default" size="100%">periodic structure</style></keyword><keyword><style  face="normal" font="default" size="100%">quercus robur l</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus Suber L</style></keyword><keyword><style  face="normal" font="default" size="100%">rhythmic growth ring</style></keyword><keyword><style  face="normal" font="default" size="100%">unit of extension</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1998///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://aob.oxfordjournals.org/content/82/1/89.short</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">82</style></volume><pages><style face="normal" font="default" size="100%">89 - 96</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">{{The anatomy of wood was studied in Quercus robur L. and Quercus suber L. seedlings exhibiting 3±8 units of extension, each with a tier of photosynthesizing leaves in their upper parts, generated as the result of rhythmic shoot growth under favourable conditions. At all the axis levels examined (i.e. the base of each of the diﬀerent units of extension, four other equidistant levels within the ®rst unit of extension and the upper part of the taproot), the wood displayed rings when treated with Wiesner reagents. This indicated cinnamaldehyde groups present in lignins. No rings appeared when the Mau$le reaction was used for speci®c detection of syringyl subunits in lignins. A trend towards a periodical arrangement of xylem parenchyma bands was also found when sections were treated with I # }KI. The number of rings coincided with the number of leaf tiers above the level of measurement, and did not vary inside the ®rst unit of extension. Thus, the rings are called rhythmic growth rings. In sections of the ®rst and the second units of extension, and in the taproot, the area and width of a given rhythmic growth ring were highly correlated with the total area of leaves present above the level of measurement at the presumed time of growth ring formation. Moreover, stem diameter at the base of the units of extension was highly correlated with the leaf area above. These results indicate that diﬀerentiation of xylem, particularly its ligni®cation, varies rhythmically in oak seedlings. They imply that wood production is linked to the photosynthesizing and}or transpiring area of the plant. Thus, during a growth cycle of Q. robur and Q. suber seedlings, there appears to be integration of the primary metabolic activities with the laying down of rhythmic growth rings</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%">MANSOUR, A</style></author><author><style face="normal" font="default" size="100%">de FAŸ, E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Rhythmic growth rings of wood and their relationship with the foliage in oak seedlings grown in a favourable environment</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%">allometric relationship</style></keyword><keyword><style  face="normal" font="default" size="100%">juvenile wood</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf area</style></keyword><keyword><style  face="normal" font="default" size="100%">lignification</style></keyword><keyword><style  face="normal" font="default" size="100%">oak seedling</style></keyword><keyword><style  face="normal" font="default" size="100%">periodic structure</style></keyword><keyword><style  face="normal" font="default" size="100%">quercus robur l</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus Suber L</style></keyword><keyword><style  face="normal" font="default" size="100%">rhythmic growth ring</style></keyword><keyword><style  face="normal" font="default" size="100%">unit of extension</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><volume><style face="normal" font="default" size="100%">82</style></volume><pages><style face="normal" font="default" size="100%">89-96</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">{{The anatomy of wood was studied in Quercus robur L. and Quercus suber L. seedlings exhibiting 3±8 units of extension, each with a tier of photosynthesizing leaves in their upper parts, generated as the result of rhythmic shoot growth under favourable conditions. At all the axis levels examined (i.e. the base of each of the diﬀerent units of extension, four other equidistant levels within the ®rst unit of extension and the upper part of the taproot), the wood displayed rings when treated with Wiesner reagents. This indicated cinnamaldehyde groups present in lignins. No rings appeared when the Mau$le reaction was used for speci®c detection of syringyl subunits in lignins. A trend towards a periodical arrangement of xylem parenchyma bands was also found when sections were treated with I # }KI. The number of rings coincided with the number of leaf tiers above the level of measurement, and did not vary inside the ®rst unit of extension. Thus, the rings are called rhythmic growth rings. In sections of the ®rst and the second units of extension, and in the taproot, the area and width of a given rhythmic growth ring were highly correlated with the total area of leaves present above the level of measurement at the presumed time of growth ring formation. Moreover, stem diameter at the base of the units of extension was highly correlated with the leaf area above. These results indicate that diﬀerentiation of xylem, particularly its ligni®cation, varies rhythmically in oak seedlings. They imply that wood production is linked to the photosynthesizing and}or transpiring area of the plant. Thus, during a growth cycle of Q. robur and Q. suber seedlings, there appears to be integration of the primary metabolic activities with the laying down of rhythmic growth rings</style></abstract></record></records></xml>