A comparative study of the effects of fluctuations in temperature and moisture supply on hard coat dormancy in seeds of coastal tropical legumes in Mexico

The effect of fluctuations in temperature and moisture supply on hard seeds of nine tropical coastal sand dune legumes, including herbs (Schrankia quadrivalvis, Macroptilium atropurpureum and Canavalia rosea), and shrubs (Acacia farnesiana, A. macracantha, Mimosa chaelocarpa, Indigofera suffruticosa, Crolalaria incana and Chamaecrista chamaecristoides), has been studied under laboratory and field conditions. Using a fluctuating temperature gradient bar seeds buried in sand were exposed to various amplitudes of diurnal temperature fluctuation over an extended period of time and seed germinability was examined at intervals. Germination percentage increased considerably in most species as a consequence of treatment with marked effects occurring at temperature fluctuations greater than 20 °C and becoming detectable after 45 days (...)