Factors influencing pollen germination in three Explorer™ roses

Abstract

Pollen germination is useful for the estimation of pollen viability. For three cultivars from the Explorer™ series, Champlain, Nicolas and Frontenac, a liquid medium with a pH of 5.6 and a saccharose concentration of 15% provides optimal germination conditions. Four flower stages were determined and evaluated according to the following scale: flower bud at stage 0 (closed bud), stage 1 (closed petals but open sepals), stage 2 (bud with petals three-quarters open) and stage 3 (fully open flower). Pollen germination was higher when the pollen was collected at stages 0 and 1 for Champlain, at stages 1 and 2 for Frontenac and at stage 2 for Nicolas. Based on the results of the evaluation of pollen drying techniques, it is recommended that pollen be dried for 24 h in darkness before use in crossing.