Investigation of pollen morphological characteristics in some quince (Cydonia oblonga Mill.) cultivars

Morphological characterization of pollen grains is very important in the identification of individual species and cultivars of fruit trees, including quince. As material for these studies, the pollen of eight quince cultivars, Leskovacka, Vranjska, Morava, Pazardzijska, Hemus, Asenica, Portugal, and Triumph was used. During the 3-year study period (2010-2012), using scanning electron microscopy (SEM), the following characteristics were investigated: the size and shape of pollen grains (length, width, and length-to-width ratio), colpus length, colpus width, mesocolpium width, and characteristics of exine pattern [number of ridges per area (100 mu m(2)) at the equatorial region of exine, ridge width, and furrow width]. The tested quince cultivars differed significantly in terms of morphological characteristics of pollen. The exceptions were colpus and mesocolpium width, as well as the ridge and furrow width on the exine, which showed no statistically significant difference. Pollen grains of quince are characterized by great length (over 53 mu m). The shape of pollen grains varied from prolate (Leskovacka, Vranjska, Morava, Hemus, Asenica, and Triumph) to perprolate (Pazardzijska and Portugal). The exine pattern of all cultivars was striate with longitudinal ridges, which were more parallel in cultivars Vranjska, Hemus, Portugal, and Triumph and less parallel in cultivars Leskovacka, Morava, Pazardzijska, and Asenica. Three groups of similar cultivars are separated on the basis of hierarchical cluster analysis results. Some pollen morphological characteristics, such as the size and shape of pollen grains and colpus length, can be used in the identification of quince cultivars