Seedling growth response to biotic and abiotic stresses in Lilium longiflorum and L. formosanum in relation to their life history strategies

Abstract

According to Grime's C-S-R concept for plant life history strategies, habitat differentiation between genetically highly related bulbous species, Lilium formosanum and L. longiflorum, were discussed from the reproductive performance of two-year-old seedlings experimentally exposed soil nutrient and light stresses. Reduction of individual flower number was significant and larger in L. formosanum than in L. longiflorum when fertilizer was not applied under sufficient light intensity. The result strongly supports the prediction that rapid growth and early onset of sexual reproduction specific to L. formosanum is reasonably demonstrated only in the highly disturbed vegetation without any stress. Lilium formosanum produced approximately 60% of malformed, unfunctional flowers in the second year of normal cultivation, but L. longiflorum did not. It is highly likely that the malformed flowers are caused by virus infection. It can be concluded that L. formosanum is so susceptible to viruses as to seriously reduce reproductive success, and thus, the species is kept out from the nutritionally less productive seaside vegetation often established on limestone soils, where L. longiflorum and calcicole species are preferably grown.