Utilização de reguladores vegetais na propagação vegetativa de clidemia blepharodes DC. e C. Suffruticosa O. Berg (Melastomataceae)

Abstract

Clidemia suffruticosa (Melastomataceae) is an endangered species. No information on its reproductive biology or seeding methods is available. In addition, the low percentage of viable seeds indicates vegetative propagation as an alternative to the multiplication of the species. The synthetic auxin most widely used on rooting of cuttings is indolbutyric acid (IAA), a photostable substance whose action in less sensitive to biological degradation. The aim of the work was to study the propagation by stem cuttings using different concentrations of IAA in C. suffruticosa and C. blepharodes. Branches of these two species were collected from adult plants in the Biological Reserve of Alto da Serra de Paranapiacaba, Santo André-SP, Brazil. Cuttings of 10cm in length were made and the bases immersed in IAA at concentrations of 0, 500, 1000, 2000 and 4000mg·l-1, for 10min. A random block design with fve treatments and fve repetitions of five plants each was used. The cuttings were placed in plastic containers using vermiculite as growing medium and cultivated in a greenhouse with daily spray irrigation. After 60 days, the percentage of live cuttings, number and length of the roots, the dry mass of the shoot and root were assessed. The averages were compared by Tukey test at 5%. The concentrations tested did not show significant differences in the assessed characteristics. It is concluded that under the conditions of the experiment, although IAA provides appropriate rooting, its use for the species under study is not justifed.