| Lily is one of most important ornamental plant and cut flower in the world. In China, the production of lily cut flower is over than 2 billion, and the requirement of lily bulbs is more than 400 million, even subtracting the reutilization of bulbs. However,80% of bulbs are imported from other countries such as Holland, due to the lack of production technology. This studies carried out technology development for scale and domestic production of lily bulbs based on natural environment resources and actual production conditions of Beijing. The study included the scale virus elimination, scale cutting propagation, tissue culture propagation, harvest technology, dormancy release of bulbs. In addition, as the importance of the release during the bulbs doemancy, the potential physiological and molecular mechanisms of it become the key problems. The results are:On the aspect of Bulb reproduction and production technology:1) Established in the Beijing area scale seedling lily bulb breeding production technical regulations. Which from stem tip in vitro culture and seedling planting get lily bulb, to lily bulb scales cuttage, seed propagation and commodity production.2) Optimized the detoxification scales cuttage propagation conditions. Choose vermiculite as substratum. When matrix and scales of the volume ratio is 3:1, the diameter and fresh weight of scales is the best. The environment temperature for rooting should be in alternative temperature:20℃～25℃ 16 w+17℃2w+5℃9w.3) Clearing the cold storage temperature control accuracy of bulb had a greater influence on the effect. Cascade temperature control method, which can effectively avoid bulb bud chilling injury, when the temperature at-1.5±0.2℃. Our results also showed that the activity of bud was slow and the cold injury was low, when the size of bulbs was bigger.On the aspect of mechanism of bulb dormancy release:1) The transcriptome sequencing further defined the starch and sucrose metabolic pathway significantly enriched in the differentially expressed genes. Dormancy ’Siberia’ bulb as control, experimental group are bulbs which storage at 4℃,8 w has breaken dormancy.The transcriptome of bulb dormancy release was analyzed by Illumina HiSeq 2000.79,354 unigenes were identified. Average length is 968bp. We identified 5,834 differentially transcript genes, including 2619 genes were up-regulated, and 3215 genes were down-regulated. KEGG pathway enrichment analysis found that lily bulb dormancy releasing is associated with hormone signal transduction and energy metabolism.2) In the transcriptomic of lily bulb dormancy release, two amylase genes have find,which expression are increased in the process of dormancy release, the expression pattern of them is matched with tendency of the changes in carbohydrate content and activity of amylase. Based on physiological indexes and transcriptome analysis of gene expression, and found that the amylase gene may involved in the lily bulb dormancy release. The alpha amylase (LiAMY) and beta amylase (LiBAM) gene won by the RACE. Real-time reverse transcriptase quantitative PCR (RT-qPCR) analysis showed that expression of both LiAMY and LiBAM increased significantly in 8 weeks of cold storage, and had a peak in week 8. In addition, the expression is still keep 7.8 times increase compared to control. This expression is consisitent with the activity of amylase, indicating that the altering of expression of both LiAMY and LiBAM promotes the starch degradation and soluble suger accumulation, may involved in dormancy release of lily bulb. |
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