INVESTIGADORES
LUQUEZ Virginia Martha Cristina
congresos y reuniones científicas
Título:
Natural variation in autumn senescence in Swedish Aspen (Populus tremula).
Autor/es:
LUQUEZ VIRGINIA; FRACHEBOUD YVAN; JANSSON STEFAN
Lugar:
Salzau
Reunión:
Workshop; Third European Workshop on Plant Senescence; 2007
Resumen:
The
natural variation in autumn leaf senescence was analyzed in a set of aspen
trees collected in 12 sites in Sweden, from 55 to 66 º of latitude; this group
of trees is known as the Swedish Aspen Collection (SwAsp, Ingvarsson et al
2006). The trees were grown in pots in a greenhouse with the natural irradiance
and photoperiod of the area of Umeå during the year 2006. During the autumn, we
measured the date of start and the rate of autumn senescence in the SwAsp.
The date
of start of autumn senescence showed a clear clinal pattern along latitude: the
populations from northern Sweden were the first to senesce and the southernmost
populations were the last ones to senesce, with a difference of 25 days between
them. The latitude of origin of the populations explained most part of the
variation in the start of senescence (R2= 0.95), suggesting that
there is an adaptation to the local environmental conditions. On the other
hand, the rate of senescence did not show any clear pattern of variation along
latitude.
We also
explored the relationship between bud set and autumn senescence. The correlation
between the start of senescence and bud set was positive and highly significant
(r=0.647, p<0.0001), implying that the trees that set buds late in the
season also had a late start of senescence, and suggesting that both are
controlled by the same environmental signal. Bud set is induced by the
reduction of photoperiod (Ingvarsson et al 2006), and the results obtained here
suggests that this is also the case for the start of autumn senescence.