The Assimilate Partitioning Importance for Heartwood Extractives Formation in Robinia Pseudoacacia l. of Different Ages

Abstract

This study aimed to investigate the influence of tree age on the assimilates partitioning and its significance for the formation of heartwood extractives in Robinia pseudoacacia L. (black locust). Assimilate translocation in 6-and 15-year-old plants was measured in May and August 2006 using the 14 CO 2 feeding method. The heartwood extractives content in the sapwood-heartwood transition zone and in individual tree rings of the pure heartwood were analysed by HPLC-chromatography. All plants, buds and young leaves showed the strongest 14C specific activity compared to other plant parts in May and August( 14 C specific activity in buds/leaves of 6-years old plants: 35.2-37.0%, 15-years old plants: 31.4-32.2%). However, in plants labelled in August 2006 at the sapwood-heartwood transition zone also showed a strong assimilates sink, while only small amounts of assimilates were translocated to the sapwood-heartwood transition zone in the plants labelled in May 2006. The amount of assimilates transported to the sapwood-heartwood transition zone was significantly higher in the 15-year-old plants compared to the 6-year-old plants. This was monitored by a higher content of extractives in the heartwood formed by the older plants compared to heartwood formed by the younger plants. The results indicate that uneven assimilate partitioning in younger and older black locust plants affects the heartwood extractives formation, which might lead to a lower natural durability of the heartwood formed by younger trees compared to heartwood formed by older trees. Keywords

Water, starch, and nuclear behavior in ray parenchyma during heartwood formation of Catalpa bungei ‘Jinsi’

“…The pith is further away from the side containing narrow TZ, which means that the variability of the TZ in the cross-section of the xylem should also have obvious directionality. The directional variation of the TZ was also found in Robinia Pseudoacacia [ 36 ], Pinus sylvestris [ 32 ], Tectona grandis [ 37 ], and Dalbergia odorifera [ 22 ]. However, these authors have no comment on this topic.…”

Characterization of the Palmyra Petiole as a Biovegetal Material of Artisanal Construction in Chad

“…For determining the ash content, we used the principle of the removal of organic matter in the petiole sample by calcination at a defined temperature in a given time. The ash rate TC(%) is calculated using formula (7).…”

Gram-Scale Purification of Dihydrorobinetin from Robinia pseudoacacia L. Wood by Centrifugal Partition Chromatography

“…Difference was observed between the mature and juvenile heartwood that presents lower resistance against wood fungi decay. Two flavonoids dihydrorobinetin (3,3 ,4 ,5 ,7-pentahydroxyflavanone, DHRob) and robinetin (3,3 ,4 ,5 ,7-pentahydroxyflavone, Rob) are the major phenolic compounds that have been extracted from R. pseudoacacia heartwood [18][19][20]. They are present in higher contents in mature heartwood compared to juvenile wood, and have thus been related to the higher decay resistance observed in mature heartwood [16,21,22].…”