The role of seed water content for the perception of temperature signals that drive dormancy changes in Polygonum aviculare buried seeds.

BENECH-ARNOLD, ROBERTO L.; MALAVERT, CRISTIAN; BATLLA, DIEGO

FUNCTIONAL PLANT BIOLOGY

CSIRO PUBLISHING

Lugar: Collingwood; Año: 2020

1445-4408

Seedling emergence in the field is strongly related to the dynamics of dormancy release and induction ofthe seed bank, which is mainly regulated by soil temperature. However, there is limited information on howtemperature-driven effects on dormancy changes are modulated by the seed hydration-level. We investigatedthe effect of seed water content (SWC) on the dormancy release and dormancy induction in Polygonum aviculareL. seeds. We characterised quantitatively the interaction between seed water content (SWC) and temperaturethrough the measurement of changes in the lower limit temperature for seed germination (Tl) during dormancychanges for seeds with different SWC. These relationships were inserted in existing population-based threshold modelsand were run against field obtained data. The model considering SWC was able to predict P. aviculare field emergencepatterns. However, failure to consider SWC led to overestimations in the emergence size and timing. Our results showthat in humid temperate habitats, the occurrence of eventual water shortages during late-winter or spring (i.e. shortperiods of water content below 31% SWC) can affect soil temperature effects on seed dormancy, and might leadreductions in the emergence size rather than to significant temporal displacements in the emergence window.In conclusion, SWC plays an important role for the perception of temperature signals that drive dormancychanges in buried seeds.