Pollen viability and germination in <i>Jatropha ribifolia</i> and <i>Jatropha mollissima</i> (<i>Euphorbiaceae</i>): Species with potential for biofuel production

Abstract

The aim of this work is to assess pollen viability using the staining  technique and in vitro germination with different concentrations of sucrose in Jatropha ribifolia and Jatropha mollissima, contributing to the knowledge of the reproductive biology and subsidizing their conservation,  management and utilization. Pollen viability was measured by dye method. Acetocarmine, acetic orcein and cotton-blue stain were used. The culture medium for pollen germination was solidificated by the addition of 1% agar combined with 0 (control), 10, 20, 30 and 40% of sucrose. The data were submitted to analysis of variance at 5% probability. All dyes used in this experiment allowed easy differentiation between fertile
and non fertile pollen. The rate of formation of pollen tubes was higher in medium with 10% of sucrose for both species because the trend is that the sucrose concentration increases the supply of carbon, changes the osmotic potential and inhibits the formation of pollen tube in vitro.

Key words: Plant reproduction, male gametophyte, hybridization, germplasm.