Morphometry and Germination of Passovia pyrifolia, Struthanthus marginatus and Phoradendron mucronatum Diaspores

Abstract

ABSTRACT: The goal of this work was to characterize morphometrically diaspores from three species of mistletoes (Passovia pyrifolia, Struthanthus marginatus e Phoradendron mucronatum), as well as to study its germination behavior according to temperature and luminosity. In germination tests, the completely randomized design was used, in factor scheme 4 x 2, with 4 replications of 15 diaspores. The factors for the first test were different temperatures and two diaspore conditions (intact and without epicarp). In the second test, factors were different light qualities and two diaspore conditions. The analyzed variables were: germination percentage, germination rate index (GRI) and mean germination time (MGT). Mistletoe’s diaspores present an elliptic shape with viscin layer, an essential characteristic for the dispersion of the species. In addition to this, they present a distinction as for the moisture content when compared to the Loranthaceae and Viscaceae, where the latter presents the highest content. Germination is greater at the alternated temperature of 20-30 oC for P. pyrifolia and P. mucronatum diaspores and 20 oC for S. marginatus. Luminosity interfered in the germination of P. mucronatum and S. marginatus but did not influence P. pyrifolia. The diaspore condition influenced the germination of the three studied species, observing a significant increase in their germination when the epicarp was removed. Temperature and luminosity interfere directly in the GRI and MGT of the three mistletoes species.

Keywords

• mistletoes
• temperature
• luminosity