POLLEN MORPHOLOGY AND VIABILITY IN SPECIES OF CANNA L. (CANNACEAE - ZINGIBERALES) AND RELAI CD HYBRIDS

Background and aims: Cultivars of Canna resulted of intensive hybridization on five parental species: C. flaccida Salsb., C. glauca L., C. indica L., C. iridiflora Ruiz et Pay. and C. warscewiczii A. Dietr. Here we study for the first time the palynological morphology and pollen viability of three hybrids belonging to the nothospecies C. x generalis and three parental species, C.glauca, C. indica and C. warscewiczii, that grow in Argentina. The objective of this work is to contribute with information about hybridization and artificial evolution of the genus Canna through a study of palynological morphology and pollen viability. M&M: Pollen grains of live flowers were observed with an optical microscopy following Wodehouse technique. As Canna pollen grains do not resist Erdtman acetolysis, the observation of sporoderm and spines was performed with a scanning electronic microscope, whereas pollen viability was studied through MTT technique, (Rodriguez-Riano & Dafni 2000). Results: In wild species the shape and size of pollen grains are regular as well as the size, morphology, distribution, and density of spines. In the hybrids the mentioned traits result irregular and spines density is 2-3 times higher. Conclusions: Pollen viability results were correlated with the presence and absence of seeds.