Predicting changes in dormancy level in natural seed soil banks

DIEGO BATLLA; ROBERTO LUIS BENECH-ARNOLD

Fargo, USA

Simposio; VI Internacional Symposium on Plant Dormancy; 2009

International Seed Science Society

  Predicting changes in dormancy level in natural seed soil banks   Diego Batlla 1and Roberto L. Benech-Arnold1   1Department of Plant Production, Faculty of Agronomy, University of Buenos Aires, Buenos Aires, Argentina   Emails: batlla@agro.uba.ar and benech@agro.uba.ar.   Understanding seed dormancy sufficiently to predict germination and seedling emergence from natural seedbanks has long been a goal to both seed ecologists and agriculturalists. In order to predict dormancy changes of buried seeds correctly we should: 1-have a clear notion of how the different environmental factors affect the dormancy level of buried seeds, 2-quantify the effects of those factors on the dormancy level of the seedbank population and 3-include the developed quantitative relationships in a coherent modeling framework. In this work we present an attempt to conceptualize the effect of environmental factors in natural seedbank dormancy level, distinguishing between factors that usually modulate dormancy level (as for example temperature) and those that usually terminates dormancy (as for example light and alternating temperatures). Based on this conceptual framework we show different approaches that can be used to establish functional relationship between soil temperature and changes in the seedbank sensitivity to factors that terminate dormancy under field conditions. Finally, we discuss the importance of a correct interpretation of temperature effects on germination, dormancy and seed aging for developing models to predict seed dormancy, showing examples of common errors that can arise when interpreting germination data sets.   Key words: Dormancy, germination, modeling, seedbank, soil temperature.