IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
EFFECT OF THERMAL STRATIFICATION CONDITIONS DURING DORMANCY RELEASE ON THE RATE OF INDUCTION INTO SECONDARY DORMANCY IN Polygonum aviculare L. SEEDS
Autor/es:
CRISTIAN MALAVERT; DIEGO BATLLA; ROBERTO LUIS BENECH-ARNOLD
Lugar:
Changsha, Hunan
Reunión:
Congreso; The 11th Conference of the International Society for Seed Science (ISSS); 2014
Institución organizadora:
International Society for Seed Science (ISSS)
Resumen:
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In seeds of many summer annual weeds low temperatures
under moist conditions provoke dormancy release while high
temperature induce secondary dormancy. These
changes in seed dormancy level establish changes in the thermal range
permissive for germination. In summer
annual seeds changes in the thermal range permissive for germination
are a consequence of changes in the lower limit temperature (Tl)
for seed germination. Numerous studies has been conducted on the
characterization of temperature on the primary dormancy release,
however, it has not been evaluated how stratification temperature
affects the subsequent rate of induction into secondary dormancy. The
aim of this work was to characterize the role of stratification
temperature on the induction of secondary dormancy in seeds of P.
aviculare.
To achieve this objective seeds of P.
aviculare were stratified at different
temperatures (1.6, 5 and 10°C) to a minimum level of dormancy. When
the seeds had a minimum level of dormancy they were induced into
secondary dormancy at 20°C. The
results showed that the rate of induction into secondary dormancy was
higher for seeds that were stratified at 1.6°C compared to those
that were stratified at 5 and 10°C. The differential patterns of
change that resulted from each stratification temperature could be
explained by a differential change in the standard deviation of Tl
at the end of the stratification period. Stratified seeds at 1.6°C
showed a deviation of 1.5, which determines a lower fraction of the
seed population able to germinate, however, seeds stratified at 5 and
10°C, showed
a higher deviation and the fraction that germinate is greater; this
determines an apparent slower induction into secondary dormancy.
Obtained results showed that the temperature experienced by the seeds
during dormancy loss can affect the subsequent rate of induction into
secondary dormancy and that these effects could be explained by
changes in the standard deviation of the Tl
permissive for seed germination.