Linkages among the functional traits, insect visitation rate and seed set of Gentiana taxa on the Tibetan Plateau.

Maximum plant height (H_max), stem tissue mass density (SD), leaf mass per area (LMA), and relative growth rate (RGR) have all been linked to flowering phenology. However, it is still unknown whether these functional traits varying with flowering phenology are related to other floral traits associated with pollinator preference and reproductive success. We investigated the relationship between vegetative and floral traits, as well as the rates of insect visitation and seed set of five Gentiana species in eastern Tibetan meadows. Our results showed that flowering onset and flowering offset time were all found to be positively correlated with the H_max, SD, and LMA, but negatively correlated with the RGR. Flowering onset time was positively correlated with corolla diameter and pollen grain number, whereas was negatively correlated with flower number and flower longevity. The rates of insect visitation were positively related to flowering onset time, pollen grain number, corolla diameter, and seed set, but negatively related to flower number and longevity. Early flowering species have higher RGR but lower SD, LMA and H_max, as well as smaller flowers, fewer pollen grains, longer flower longevity, and lower insect visitation rates than late-flowering plant species. Our findings indicate that floral traits are related to vegetative traits in Gentiana species. Also these plant trait relationships were associated with pollinator preference, and plant reproductive success of eastern Tibetan meadows. We speculate that these traits relationships are likely adaptive in unpredictable and often pollinator-limited environments in the Tibet alpine meadows. [ABSTRACT FROM AUTHOR]