バラの花粉外壁の形態計測分析

Abstract

Pollen grain morphology of 125 taxa of roses was examined by using scanning electron microscope (SEM) and by subsequent principal component analysis, in order to clarify the phylogenetic relationships. Nine categories of pollen-surface type were confirmed by scrutinizing ridge and perforation features on pollen exine. Species belonging to a botanical section or cultivars belonging to a horticultural cultivar group showed specific pollen exine patterns, and it was suggested that the specific pollen exine pattern transmits well from wild species to cultivars during several generations.A principal component analysis using six quantitative traits of pollen grains well separated the groups of roses. The wild species with high ploidy levels and the many cultivars belonging to the Hybrid Tea and Floribunda groups were distinguishable from the wild species of low ploidy level and from the other cultivar groups by the score of the first principal component. The species of the section Pimpinellifoliae and their related cultivars were characterized by the score of the second principal component, and the species of the section Indicae and their related cultivars by the score of the third principal component.Thus, the features of the perforations and ridges of the pollen exine seem to be good tools to distinguish each botanical section or horticultural cultivar group in roses.