Lycoris Herb., also called ‘Magic lily’, ‘Surprise lily’, or ‘Spider lily’ (Adams, 1976), is a genus of Amaryllidaceae that is native to East Asia. In many local Chinese dialects, Lycoris species have commonly been called “stone garlic,” referring to their onion-like bulbs, which are inedible (Qin et al., 2003). The plants have ornamental value because of their beautiful flowers and attractive foliage (Zhang and Cao, 2001) and have been used as potted and landscape plants for several hundred years. Lycoris have fasciculate, emerald or bottle-green belt leaves that are similar to those of cymbidium. In the past several decades, some of the Lycoris species, cultivars, and hybrids such as L. radiata (L'Her.) Herb and L. aurea (L’Her.) Herb have been used worldwide. More than 10 species and cultivars are in cultivation in Australia. The demand for Lycoris as a commercial horticultural product has been increasing steadily.
There are more than 20 species in the Lycoris genus (Hsu et al., 1994), but only L. radiata and L. aurea have been widely cultivated and commanded commercial values as ornamental plants. Choi (1991) and Zhang and Cao (2001) reported that L. radiata grew best at 65% and worst at 5% of full sunlight among the irradiance levels (from 5% to 80% sunlight) studied. Lu and Xu (1988) and Zhang and Cao (2001) found that L. aurea had better cut flower quality when grown at 50% sunlight. Three other Lycoris species, L. chinensis Traub, L. longituba Xu & Fan, and L. sprengeri Comes ex Baker, have been cultivated in China for many years and the market for these species has rapidly developed in recent years. Wild populations of these species in their natural habitat are frequently found on warm and moist sites in locations under a certain degree of shade (Qin et al., 2003). However, little information is available on the response of these Lycoris species to various irradiance levels. A better understanding of how these species respond to shade in cultivation, both in terms of growth rates and ornamental value, can greatly affect the commercial production of those species for the horticulture industry.
The objective of this study was to investigate the responses in chlorophyll concentration, rate of net photosynthesis, growth, and biomass allocation of three Lycoris species to various levels of irradiance. Results from this study should provide useful information for improving the cultivation of these species.
Aleric, L.M. & Kirkman, L.K. 2005 Growth and photosynthetic response of the federally endangered shrub, Lindera melissifolia (Lauraceae) to varied light environments Amer. J. Bot. 92 682 689
Björkman, O. 1981 Responses to different quantum flux densities. Physiological plant ecology. I. Responses to the physical environment Lange O.L., Nobel P.S., Osmond C.B. & Ziegler H. Encyclopedia of Plant Physio 12A 57 107
Choi, S.K. 1991 Studies on the culture of Lycoris radiata Herb. as a medicinal plant. 1. The effect of bulb size at planting on plant growth and bulb yield. Research Reports of the Rural Development Administration Upland Industrial Crops. 33 84 88
Dale, M.P. & Causton, D.R. 1992 Use of the chlorophyll a/b ratio as a bioassay for the light environment of a plant Funct. Ecol. 6 190 196
Lee, D.W., Oberbauer, S.F., Johnson, P., Krishnapilay, B., Mansor, M., Mohamad, H. & Yap, S.K. 2000 Effects of irradiance and spectral quality on leaf structure and function in seedlings of two Southeast Asian Hopea (Dipterocarpaceae) species Amer. J. Bot. 87 447 455
Lei, T.T. & Lechowicz, M.J. 1997 Functional responses of Acer species to two simulated forest gap environments: Leaf level properties and photosynthesis Photosynthetica 33 277 289
Lei, T.T., Tabuchi, R., Kitao, M. & Koike, T. 1996 Functional relationship between chlorophyll content and leaf reflectance, and light-capturing efficiency of Japanese forest species Physiol. Plant. 96 411 418
Li, Y.P., Yu, F. & Tang, Q.G. 2004 Effects of planting density and shading level on the growth and the quality of cut flowers of Lycoris radiata J. Nanjing Forest Univ. (Nat. Sci. Ed.). 28 93 95
Peek, M.S., Russekcohen, E., Wait, D.A. & Forseth, I.N. 2002 Physiological response curve analysis using nonlinear mixed models Oecologia 132 175 180
Poorter, H. & Nagel, O.W. 2000 The role of biomass allocation in the growth response of plants to different levels of light, CO2, nutrients and water: A quantitative review Aust. J. Plant Physiol. 27 595 607
Potvin, C., Lechowicz, M.J. & Tardif, S. 1990 The statistical analysis of ecophysiological response curves obtained from experiments involving repeated measures Ecology 71 1389 1400