Efeito da temperatura e do substrato na germinação de Hamatocactus setispinus (Cactaceae)
Cacti are widely used as ornamental plants and seed germination is a major method for preserving genetic diversity. Thus, an experiment was carried out to evaluate the effects of different temperatures and substrates on seed germination of Hamatocactus setispinus. Seeds were sown in gerbox boxes containing either germination paper (S1), sand (S2) or vermiculite (S3). After placing the seeds on the substrates, the boxes were kept in germination chambers at 20, 25, 30 and 35° C for 30 days, under a photoperiod of 16 hours. The experiment was in a completely randomized design with four replicates. The speed germination index (SGI), mean germination time (MT) and germination rates (%) were evaluated. The best results were observed at 25º C. The highest SGI (3.94) was observed on seed germination paper, but MT values and germination rates on this substrate did not differ from those obtained on sand. Therefore, both substrates could be used for germination of this cactus species.