RESPONSES OF FLORAL TRAITS OF HYSTERANTHOUS TREES TO TEMPERATURE IN SHANGHAI

The flower is the most sensitive organ of a plant and responds directly and rapidly to climate warming. Temperature influences floral traits, such as floral size, floral longevity, floral water content, and floral density. There are many hysteranthous tree species in urban forests, and these trees play a key role in landscape beautification and early spring greening. This study aimed to investigate the effects of temperature change on floral characteristics of eight hysteranthous tree species, with a particular focus on the regulatory effects of artificial emasculation and estrogen treatment on flower longevity, including Prunus serrulata, Magnolia denudata, Magnolia liliiflora, Chaenomeles speciosa, Malus halliana, Cercis chinensis, Syringa oblata var. alba, and Syringa oblata. It was hypothesized that experiments conducted at both elevated and reduced temperatures would demonstrate a substantial impact of temperature on floral characteristics, water content, and longevity. The artificial emasculation treatment was predicted to curtail floral longevity under elevated temperatures, while the estrogen treatment was anticipated to prolong it, particularly under such conditions. The outcomes of this study will contribute to the comprehension of the potential ramifications of climate change on the reproductive ecology of urban greening plants, thereby providing a scientific foundation for urban greening and plant protection initiatives.