Comprehensive analysis of reproductive ecology in Jasione supina: A multi-subspecies perspective

This study examines the variation in reproductive traits among four subspecies of Jasione supina (subsp. akmanii, subsp. pontica, subsp. supina, and subsp. tmolea) endemic to Turkey. Key parameters such as flowering phenology, floral morphology, ovule and pollen characteristics, pollen viability, stigma receptivity, self-incompatibility, and pollinator visitation were comparatively analyzed under field conditions. J. supina subsp. supina exhibited the greatest reproductive success, with the highest number of corymbs per plant (25.93 ± 16.09), flowers per corymb (36 ± 11.66), ovules per ovary (24.1 ± 3.07), and fertilised ovules (19.9 ± 4.36). It also exhibited the highest pre-anthesis pollen viability (86.5 ± 6.26%). Despite having a lower floral output, J. s. tmolea achieved high fertilisation rates (12.2 ± 2.35 ovules) and had the highest post-anthesis pollen viability (67.5 ± 16.87%). Subsp. akmanii produced the highest pollen count (2110 ± 435.12) but had the lowest pre-anthesis pollen viability (56 ± 14.3%). Self-pollination resulted in zero fertilisation in all subspecies, confirming complete self-incompatibility. Under cross-pollination, fertilization rates ranged from 41.83% in subsp. pontica to 82.75% in subsp. supina. Physical stimulation of pollen-collecting stylar hairs significantly reduced the time to female-phase onset, from 22–26 hours to 6–6.75 hours after anthesis. Pollinator observations over a period of 216 hours revealed that Hymenoptera accounted for 63.33% of visits, followed by Diptera (34.6%), Lepidoptera (1.88%), and Coleoptera (0.03%). Subsp. pontica was the only subspecies in which Diptera exceeded Hymenoptera in visitation frequency. These results indicate that floral traits, pollinator composition, and reproductive efficiency vary significantly among subspecies, which supports the hypothesis that divergent evolutionary pressures and ecological heterogeneity have shaped distinct reproductive strategies within the Jasione supina complex.