The Effects Of Weak Light On The Growth, Development And Physiological Characteristics Of Cut-lilies

Lily is an important cut-flower grown under protected cultivation in winter and spring in China. At present weak light stress is one of the main restrict factors on influencing the production of lily under protected cultivation. In recent years, studies on the characteristic of cut lilies under low light are quite limited at home and abroad. To provide the theoretic basis for lily breeding of weak light tolerance, the growth, development and photosynthetic characteristics of cut lilies were studied under weak light. In the paper, using Lilium "Oriental hybrids",Lilium "Asiatic hybrids" and Lilium "L/A hybrids" as materials, we investigated the response of growth,development and Physiological Characteristic on low light, and the change of morpha under low light in Lilium "L/A hybrids". And the cultivars with low light tolerance were selected with the method of Membership Function Synthetical Evaluation. The main results were as follows:1. The growth and development of the cultivars of Lilium "Oriental hybrids" decreased under low light, the effective leaf area increased and specific leaf mass (SLM) dropped. The plants had the symptom of slight spindling; excessive growth. And the quality of cut flowers was decreased. Howerver the cultivars in Lilium "Asiatic hybrids" were more sensitive to the cultivars in Lilium "Oriental hybrids". The specific leaf mass (SLM) was falling, dry weight of cut flower decreased significantly, and biomass synthesis decreased which resulted in the flower buds taken off.So the quality of Lilium "Asiatic hybrids" was falling significantly.2.When the light intensity was 180-250μmol/m2, the cultivars such as'Termoli','Serrada'of Lilium "L/A hybrids" could grow normally, while the light intensity was less 90-130μmol/m2,'Termoli' and'Serrada'could not grow healthily, and the flower buds were taken off significantly. The number of flower buds in'Termoli'was less than'Serrada'.3.In Lilium "Oriental hybrids",'Marcopolo'had better shading resistance than others. The light compensation point(LCP), dark respiration rate (Rd)and specific leaf mass(SLM) of'Marcopolo'was lower than other three varieties, and the change of apparent quantum yield(AQY) was small under 75% shadings (50μmol/m2-70μmol/m2),while'Acapulco'was sensitive to low light.4. In Lilium "Asiatic hybrids",'Vermeer'and'Loreto'had better shading resistance, photosynthetic capacity decreased less,and assimilation was higher. The plants grew strongly, which were suitable for grow in winter and summer in north place of China. The normal light intensity (180-250μmol/m2) made'Navona'grown unhealthily and it is considered unsuitable to grow in the winter of north China.5. The cultivar'Marcopolo'of Lilium "Oriental hybrids"and'Vermeer','Loreto'of Lilium "Asiatic hybrids" have better resistance to weak light, and they could be considered to be the parent-materials to foster the cultivars of weak light resistance. Specific leaf mass could be the index of weak light resistant identification.The study provided the theoretic basis for lily breeding of weak light tolerance which are suitable for growing in the greenhouse in winter and spring of north China and provided new methods for the cut-lilies'selection of weak light tolerance.