Modelling changing sensitivity to alternating temperatures during induction of secondary dormancy in buried Polygonum aviculare L. seeds to aid in managing seed-bank behavior

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

WEED RESEARCH

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2022

0043-1737

Seed dormancy is a common attribute of many weed species in temperate habitats thatcontrols the seasonal annual pattern of weed emergence from soil seedbanks. For someof these weed species, it is not enough to reach a low dormancy, but germination canproceed only after the requirement for dormancy termination factors (i.e., light andalternating temperatures) have been satisfied. It is documented that sensitivity toalternating temperatures in Polygonum aviculare seeds increases during dormancyrelease. However, it is not known whether this sensitivity is lost during dormancyinduction. The aim of this study was to investigate and quantify the changes in dormancy level of P. aviculare seeds during induction into secondary dormancy, as measured bychanges in sensitivity to alternating temperatures driven by the soil temperature. Toachieve these objectives, P. aviculare seeds were stratified at 5oC until obtaining a minimum dormancy level. The seeds were then buried in pots and induced into secondary dormancy by storing them at 10, 15, 20 and 25oC for different time-periods. Duringstorage, P aviculare seeds were exhumed periodically and exposed to different cycle- doses of 10/24oC (12hs/12hs) (0, 1, 3, 5 and 15 cycles) to test germination. Our resultsshowed that the high sensitivity to alternating temperatures achieved during primary dormancy release, decreases during secondary dormancy induction with a rate that is temperature-dependent. These changes in sensitivity to alternating temperatures were quantified as a function of the accumulation of thermal-time which is calculated over abase-temperature of 7.9oC. Coupling the present model with a previously obtained one to assess changes in sensitivity to alternating temperatures during dormancy release, allowed us to develop a model for the prediction of cyclic changes in sensitivity to alternating temperature in relation to the thermal environment experienced by the seedsduring burial. This model constitutes a valuable tool for managing weed seedbank through different agronomic practices.