Pollen viability of Peltodon longipes using distinct staining methods

Abstract

The pollen viability reveals the masculine breeding potential in plant species, and can be useful for taxonomic, ecological, genetic and palynological studies. In order to provide information on the medicinal species Peltodon longipes Kunth ex Benth., this study aimed at estimating the pollen viability in accessions of this species collected in the state of Rio Grande do Sul, by using three staining methods, as well as determining the most efficient stain. The inflorescences of 15 accessions were collected and fixed in ethanol/acetic acid (3:1 v/v) for 24 h and, subsequently, placed in 70% (v/v) ethanol under refrigeration until preparation of slides by the squashing technique. Three staining methods were used: acetic orcein 2%, acetic carmine 2%, and Alexander’s stain. Pollen grains stained with acetic orcein 2% with intense coloring were considered viable, while those of weak coloring were considered non-viable. The grains treated with acetic carmine 2% were considered viable when they were stained red, whereas the transparent ones and those showing no staining were considered non-viable. The pollen grains stained with Alexander’s stain were viable when the pollen was purple and non-viable when it was light blue-green. A completely randomized design was used and the data collected was submitted to analysis of variance (ANOVA) and compared by the Scott-Knott test at 5% probability of error. Of the 15 accessions of P. longipes, 13 showed high pollen viability, with values above 75% and the methods using acetic carmine 2% and Alexander reactive, were the most efficient technique for this species.