Comparative Pollen Morphology of the Genus Chaenomeles Lindl. (Rosaceae): Diagnostic Features and Implications for Taxonomy

The taxonomic placements of Chaenomeles Lindl. (Rosaceae) and their intrageneric species have long been controversial. This research aims to explore the palynomorphological characters all extant in detail compare results with phylogenetic relationships classification scheme. pollen morphology 30 individuals six taxa was investigated using both light microscopy scanning electron microscopy. pollens were measured, observed statistically analyzed for 12 quantitative features 2 qualitative ones. study revealed that are monad, tri-colporate, medium size (P = 32.78–42.74 μm, E 30.42–36.31 μm) prolatespheroidal subprolate shape (P/E 0.98–1.35). Based on exine ornamentation under SEM, two sexine sculpture types (type I—striate microperforations, type II—striate macroperforations) subtypes (twisted-striate, reticulate-striate) recognized genus. Statistical analysis identified some characteristics diagnostic importance, including shape, colpus dimension, length or direction striae diameter perforation. These may value genus family Rosaceae. An artificial key studied species, based micromorphological attributes, is also provided. obtained result basically consistent molecular studies published earlier. study, first time, provides palynological evidence hybrid origin hypothesis C. sinensis supports placement this monotypic Pseudocydonia.