Pollen Morphology and Quality of Twenty Olive (Olea europaea L.) Cultivars Grown in Portugal

摘要

Pollen morphology and quality of 20 olive cultivars grown in Portugal were analysed and multivariate statistical analysis was performed in order to group the cultivars with similar characteristics. The morphology was analysed by scanning electron microscopy and the quality was evaluated through pollen viability and in vitro germination. Pollen grains from the studied cultivars were elliptical, subprolate or prolate spheroidal with an average size (22x20 um), 3-zonocolpate for the majority of cultivars but 3-zonocolporate for three of the cultivars studied. Pollen viability varied between 76% ('Verdeal de Trás-os-Montes') to 6% ('Madural') and the germination varied between 65% ('Verdeal de Trás-os-Montes') and 2% ('Conserva de Elvas'). Hierarchical Cluster analysis based on all characteristics analysed, showed an organization into three groups composed by cultivars with similar pollen morphometry characteristics and percentages of pollen viability and in vitro germination. Our results indicate that the highest values of olive pollen viability and germination are associated with highest average values of pollen exine reticulum thickness and diameter.