Chromosome number in meiotic stage cells and pollen viability of Vanhouttea hilariana Chautems, Vanhouttea brueggeri Chautems and an interespecific hybrid (Gesneriaceae)

Abstract

Vanhouttea (Gesneriaceae) is a genus from Brazilian rock mountains. Two species, Vanhouttea hilariana Chautems and Vanhouttea brueggeri Chautems, are very similar, differentiated just by the calyx morphology. The hypothesis of hybridization between these species was suggested by many authors mainly by the observation of individuals in the populations with intermediate morphology. The aim of this work was to determine the chromosome number and to evaluate the meiosis behavior and pollen viability of these two species and the putative hybrid. The analyses of the putative parental and hybrid revealed that all individuals have 2n=26 and a normal meiosis behavior. Nevertheless, although the pollen grains of possible parental has been viable, it was observed around 92.87% of unviable pollen from all putative hybrids analyzed which reinforce the hypothesis of hybridization between V. hilariana and V. brueggeri.