Microsporogenesis, viability and pollen morphology of five species of Vochysiaceae A.St.-Hil. from a midwestern Brazilian savannah

Despite the growing interest in investigating the reproductive biology of Vochysiaceae A.St.-Hil., more in-depth descriptions of the floral details of its group are needed. Within this context, the present study was conducted to evaluate the stages of microsporogenesis, viability and pollen morphology of the Vochysiaceae species found in a fragment of the Cerrado in the state of Mato Grosso, Brazil. For this purpose, flower buds were collected and prepared for meiotic analysis, acetolysis and scanning electron microscopy. In all analyzed species (Qualea grandiflora Mart., Qualea multiflora Mart., Qualea parviflora Mart., Vochysia cinnamomea Pohl and Vochysia divergens Pohl), meiosis was regular, with a meiotic index greater than 90%, correlating with a high pollen viability rate (greater than 70%). The pollen grains of the five species showed similarities in terms of dispersion, symmetry, polarity and apertural pattern and varied in size between small and medium, oblate-spheroidal and prolate shapes. Based on the multivariate multidimensional scaling analysis, when including quantitative and categorical variables of pollen morphology, the species were able to be satisfactorily differentiated. This approach for the species of Vochysiaceae in the Brazilian savannah (Cerrado) is novel, provides an important source of data for future research on the distribution and evolution of this family, and can be used to foster discussions regarding the delimitation of priority areas for conservation.