Combined Morphological and Palynological Classification for Hibiscus syriacus L. (Malvaceae): Construction of the Diagnostic Classification Framework and Implications of Pollen Morphological Variation on Fruiting

Identifying useful taxonomic indicators for classifying Hibiscus syriacus L. (Malvaceae) cultivars can help address challenges in their homonymy and synonymy. Moreover, analyzing which pollen traits possibly lead to successful fruiting serve guide the hybridization breeding of H. syriacus. For first time, this study classified 24 based on morphological palynological assessed flowers, leaves, grains. These were a mixture quantitative qualitative traits, measured contribute identification classification cultivars. The results showed that could be into 2–6 clusters according different criteria. leading diagnostic eight two new traits—the width spine base (SW) average grain radius length (D-spine)—and five amount surface spines (O-SA), whether petals have red center (B-RC), ruffles strongly (B-RS), degree ruffling (O-DR), relationship between calyx bract (O-CB)—could used as defining owing robust contribution classification. correlations grains explored, revealed O-SA was tied traits. Furthermore, three traits—whether stamens are heterogeneous terms inner (B-IP), O-CB, leaf lobing is strong (B-LL)—were correlated with partial We also found those micro-spines or granulate higher rates; additionally, diameter, length, spacing might potential factors influencing breeding. insights gained from fill key knowledge gap concerning criteria suitable distinguishing Our findings provide timely information how understand pollination process, especially aspects pollinator selection via features, influence programs outcomes.