Effects of temperature and pretreatments on seed germination of nine semiarid species from NE Spain

Abstract

The aim of this work was to study the seed germination characteristics, under different incubation temperatures and using different pretreatments for promoting germination, of nine species, Boleum asperum (Pers.) Desvaux, Centaurea pinnata Pau, Halopeplis amplexicaulis (Vahl.) Ung.-Sternb, Krascheninnikovia ceratoides (L.) Gueldenst, Lythrum flexuosum Lag., Microcnemum coralloides (Loscos & Pardo) Buen, Pucinellia pungens (Pau) Paunero, Thymus loscosii Willk., and Vella pseudocytisus L. subsp. paui Gomez Campo, that grow in semiarid regions of NE Spain. In eight of these species, seeds collected from several (2-9) populations were tested. Constant 15 C, 20 C, or 25 C, and alternating 15/25 C temperature regimes and 16/8 hours light/dark photoperiod conditions were used. In seeds from the different populations of Halopeplis amplexicaulis and Microcnemum coralloides, manual scarification, dry heat, and soaking in gibberellic acid solution were used as pretreatments applied for enhancing germination. Germina...