Floral longevity is related to flower nutrient stoichiometry in endangered orchids, Paphiopedilum species

Abstract

The relationship between floral longevity and the chemical elements that support plant survival, growth and reproduction remains unclear. Here, we used 12 Paphiopedilum (Cypripedioideae, Orchidaceae) species with long-lived flowers to investigate the possible association of chemical elements with floral longevity. We found that floral longevity was significant and positive related to the contents of phosphorus, calcium, magnesium, and silicon in flowers, but was not significantly related to carbon, nitrogen, potassium or boron contents. In addition, the contents of certain chemical elements in flowers were correlated. In our principal component analysis of eight floral trace elements and floral longevity, the first two principal components explained 50.5% and 20.5% of the total variation, respectively. The second major axis of calcium variation in flowers was independent of the first major axis. Our findings highlight a relationship between floral longevity and nutrient stoichiometry that needs to be understood when developing conservation plans for endangered orchids of Paphiopedilum species.