Descripción
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After decades of decline of the tapping activity, the sector has recently experienced a resurgence with some attempts at mechanization. Maritime pine (Pinus pinaster Ait.) has been the chief species, and nowadays the only one tapped for oleoresin in the western Mediterranean countries. The oleoresin flow in P. pinaster is associated to the anatomy of the interconnected and widely developed resin canals, which synthesize and store oleoresin. In this study we evaluated the influence of the tapping wound and of different tapping methods on the wood anatomy. Eight previously unwounded mature trees were tapped during five months with 4 different methods (mechanical and traditional, ascendant and descendant) in 2011. Nine cores per tree were collected 30 months after tapping (January 2014) from tissues surrounding the tapping wound, at three different orientations (above, below and aside) and at three different distances from the wound boundaries (3, 15 and 30 cm). Six anatomical variables were measured (cross section) in the 2010-2013 growth rings: the number of axial canals per mm2, the area of axial canals per mm2; the mean size of axial canals, and the radial increment of earlywood, latewood and growth ring. The strongest xylem wood reactions were found in the first 15 cm above and below the wound boundary. In the tapping year (2011), the increment of the growth ring decreased up to four times compared to control, unwounded, trees. By contrast, two years after tapping (2013), an important increase in latewood and growth ring increment was observed aside of the wound due to callus formation. One year after tapping (2012), axial resin duct frequency and surface were four times higher than in the previous year, but the mean size of axial canals decreased. However, two years after tapping (2013), the frequency, surface and size of axial canals returned to similar values than the control trees. Traumatic resin duct formation, incomplete lignification of tracheids and formation of suberin bands were observed above and close to the wound boundary only in the tapping year. All the methods tested caused similar responses in xylem anatomy. The most significant difference was a higher increase in the frequency and surface of axial canals with the ascendant mechanical method. The variations on the canal system of pines should be taken into account to improve tapping techniques and resin yield. | |
Internacional
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Si |
Nombre congreso
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5th International Conference on Mediterranean Pines (medpine5) |
Tipo de participación
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960 |
Lugar del congreso
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Revisores
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Si |
ISBN o ISSN
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00-0000-000-0 |
DOI
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Fecha inicio congreso
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22/09/2014 |
Fecha fin congreso
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26/09/2014 |
Desde la página
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122 |
Hasta la página
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122 |
Título de las actas
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Book of abstracts |