Pollen Morphology of Ornamental Peach Cultivars

Pollen grains of 39 cultivars of ornamental peach (Prunus persica) which belong to upright, dwarf, weeping, pillar, twist-twigs, and David groups (hybrid with P. davidiana), were examined by using scanning electron microscopy (SEM). The pollen grains of ornamental peach are large in size and prolate or perprolate in shape. The polar axis (P) and equatorial diameter (E), P/E, distance between furrows and the width of ridges were measured for 9 grains of each cultivar. The average length of pollen grain longitudinal axis ranges from 57.5 to 66.7 mu m. The average length of their equatorial diameter ranges from 29.7 to 36.5 mu m. The results indicated that the pollen morphology is diverse. Four major exine sculpture types were observed: (1) perforate, (2) regularly striate and perforate, (3) irregularly striate and perforate, and (4) striate. The differences of exine sculpture provide useful information for cultivars evolution. Pollen characteristics appear to be morphologically informative and supportive for describing and identifying ornamental peach cultivars.