Genetic control of coppice and lignotuber development in Eucalyptus globulus
2003
Whittock, S.P. | Apiolaza, L.A. | Kelly, C.M. | Potts, B.M.
The economics of short-rotation pulpwood plantations of Eucalyptus globulus as a coppice crop are influenced by stump survival and subsequent coppice growth rates. This study revealed significant genetic diversity in coppicing traits, both within and between subraces, following felling in a progeny trial after 9 years of growth. A total of 67% of trees coppiced after 14 months, but subraces varied from 43 to 73%. Heritabilities for coppice success (0.07) and subsequent growth (0.16-0.17) were low but statistically significant. Strong genetic correlation between presence/absence of coppice, the number of stems coppicing from the stump and modal coppice height, indicate that selection is possible by using the binary trait. The ability of a tree to coppice was genetically correlated with tree growth prior to felling (rg = 0.61) and with nursery-grown seedling traits, where large genetic differences were observed in the development of lignotubers. Coppicing was genetically correlated with the number of nodes with lignotubers (rg = 0.66) and seedling stem diameter at the cotyledonary node (rg = 0.91). These traits were uncorrelated with later age growth and with each other. The results suggest that coppicing is influenced by three independent mechanisms-lignotuber development, enlargement of the seedling stem at the cotyledonary node and vigorous growth-which enhance ability to survive catastrophic damage, and indicate that both lignotuber and coppice development can be altered by both natural and artificial selection.
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