The scaling is a technique for propagation of Lilium (Gray, 1974; Marinangeli and Curvetto, 1997; Marinangeli et al., 2003). The mother bulbs are scaled and stored in a favorable substrate. Scale bulblets develop on the sides of the individual mother scale (Gray, 1974). This method was studied and reported earlier (Matsuo, 1972; Matsuo and Van Tuyl, 1984; Matsuo et al., 1989; Cabrera, 2002). Addai (2010) found the sucrose as an essential and major carbohydrate in Lilium bulb, because breaking and metabolism of this sugar are important to facilitate the growth of storage organ, inflorescence and others. However, Addai (2010) noticed that starch is a major carbohydrate and as an energy source for bulbous plants such as lily before vernalization. After vernalization, starch breaks to sucrose and reducing sugars (Xu et al., 2006), this phenomenon referred to low temperature sweetening, and has been reported in Lilium, Hyacinthus and Tulipa as well (Miller and Langhans, 1990). Sucrose is a soluble carbohydrate, which is essential for growth of plants, and is as first transfer carbohydrate in more plants. The accumulation of sucrose in scale tissue of bulb can cause sprouting and growing plant (Xu et al., 2006). After translocation of starch from chloroplast and amyloplast to cytosol, UDP-glucose is a start-point of sucrose synthesis. Thus, glucose is a molecule key in synthesizing sucrose, and also glucose is a photosynthesis product its own, and with other photosynthetic product, fructose, produce a sucrose. Addai (2010) described that metabolism of sucrose, glucose and starch supply necessary energy to sprout and the emergence of shoot and roots, also he noticed that fructose accumulate in scales and has a role in sprouting bulb. However, starch or glucose has also inter-converted to fructose. He found that the metabolism both of sucrose and glucose as well as starch is important to sprout the bulb.
Bulbs, corms, tubers and other storage organs of plants contain the hydrolactic enzymes of starch, i.e. α- and β- amylases (EC 188.8.131.52 and EC 184.108.40.206, respectively). β- Amylase is an exo-enzyme which breaks α-1,4-glucoside bands from the non-reducing end of starch, and produces maltose and β- limit dextrin molecules. However, α- amylase is an endo-amylase, which breaks non-terminal glucosidal bands, and produces glucose, maltose and branched oligosaccharides (Addai, 2010).
The content of carbohydrate and the activity of amylases affect quality of sprouting scale bulblets after vernalization. The objective of this study was evaluating how the effect of storage duration on the quality (metabolism of soluble carbohydrate and the activities of amylases) in ʻArabian Redʼ.
2. Materials and methods
2.1. Plant material
Middle Scales on basal plate oriental hybrid lily ʻArabian Redʼ bulbs (18 - 20 cm in circumference, Van den Bos, Netherlands) with the same weight (2 - 2.5 g) were scaled. Scales were dipped for 15 min in a fungicide solution...