Abstract:

【Objective】 The effects of IBA and GA3 on starch-sucrose metabolism during scale cutting propagation were studied with the aim to provide a theoretical and practical basis for regulating the development of bulblets and explore the physiological mechanism of scale propagation.【Method】The scales of Lilium Asiatic hybrids ‘Elite’ were immersed in IBA solution at concentration 200 mg?L-1 for 2 h and GA3 solution at concentration 200 mg?L-1 for 8 h, respectively. And the control was designed with water in same volume 2 h. The starch content, sucrose content and the activities of related enzymes in various positions of mother scales and bulblets were determined. 【Result】 Results showed that IBA and GA3 accelerated the starch degradation, sucrose synthesis and the transfer of carbohydrate from apical, central regions to basal region in mother scales. Furthermore, these substantial changes speeded up the bulblet morphopoiesis. Starch degradation was partly regulated by SP in parent scales, and the sucrose content was significantly positively correlated with the SS as well as SPS activity. The efficiency of IBA on carbohydrates metabolism was higher than that of GA3. Besides, IBA was conducive to synthesize sucrose earlier in the mother scales. By comparison, GA3 restrained the degradation of starch in the mother scales during the initial culture period and promoted more sucrose synthesis. 【Conclusion】 IBA and GA3 promoted the metabolism of starch as well as sucrose, and increased the activities of related enzymes in the parent scales, and then improved the propagation coefficient or produced the optimum bulblets.

Key words: lily, scale cutting, starch, sucrose