Effects of maternal and post-dispersal environments on Amaranthus hybridus seed dormancy loss

ROCIO BELÉN FERNANDEZ; BENECH-ARNOLD, ROBERTO; BATLLA, DIEGO

Congreso; XXXI Reunion Argentina de Fisiología Vegetal; 2016

Although buried seeds dormancy changesdepend on the environment experience by seedafter-dispersal, there is evidence indicating thatdormancy loss dynamics can be also affected bythe environmental conditions experienced byseeds during its maturation on the mother plant(maternal effect). In this work, we studied theeffects of maternal and post-dispersalenvironmental conditions on Amaranthushybridus seeds dormancy loss. To achieve thisobjective, we carried out plantings under fieldconditions from September to January, exposingseeds to different environmental conditionsduring development and maturation. Harvestedseeds were buried in pots and stored at differenttemperatures (5 or 25ºC) and humidity regimes(dry, moist or fluctuating soil water content).Along storage, germination was tested atconstant (10, 15, 20, 25, 30ºC) and alternating(10/24 and 20/30ºC) temperatures. Resultsindicated that dormancy level of newly dispersedseeds and its evolution during subsequentstorage were influenced by the maternalenvironment. Seeds from later sowingsmaturation environments showed a lowerdormancy level at harvest and a faster dormancyrelease during storage. On the other hand, seedsstored at 5ºC under moist or fluctuating waterregimes conditions showed a significantly higherrate of dormancy loss than those stored dry at 5and 25ºC.