Effects Of Temperature Treatments On Hormones Content And Bud Development Of Dormant Bulb In Tulip

Tulip is a famous flower in the word, study the relationship between temperature treatments on physicohemical properties and bud development and bulbs dormancy is helpful the ornamental cultivation anniversary. Select 8-10 cm bulbs of tulip cultivar Golden Apeldoorn and stored in room temperature(10-18℃), 5℃, 0℃and-12℃ and changing temperature. Test the changes of GA3、IAA、ABA by HPLC before treatment, 2nd week, 4th week, 6thweek, 8th week, 10 th week, 12 th week and 13 th week during treatments. In addition test the changes of moisture, soluble sugar starch content,SOD and POD, meanwhile observe the bud development in each temperature under microscope before treatments, 4th week, 8th week, 12 th week and 13 th week during treatments separately. After 13 weeks stored, plant the bulbs in the green house then statistical emergence rate and flowering rate. The experiment result were as follows:1.A method which was detected by high performance liquid chromatographic(HPLC) and extracted by isopropy alcohol solution for the simultaneous determ ination of three kinds of endogenous hormone gibberellin(GA3), auxin(IAA),and abscisic acid(ABA) content in tulip bulbs was descried. The chromatograpgic separetion was carried out on a reverse phase C18 colum using V(Met):V(0.07% acetic acid)=45:55 as the mobile phase at a colum temperature of 20℃,the flow rate was 1.0 m L/min,UV detection at 212 nm was used for separation GA3 from 3min to 4.5 min, while detection at 218 nm was used for separation IAA from 4.5min to 6.5 min, then detection at 265 nm was used for separation ABA at remaining time.The injection volum wasd 10μ L.It shows a reliable method for rapid accurate separation and determ ination endogenous hormone in tulip bulbs.2. Under the treatments of different temperatures, there are 2 peaks at the content of GA3, the temperature is higher the peak is earlier and higher. There is a peak in every treatment of IAA content at 6th week or 8th week, but after that the amout of IAA is lower than 4th week, which is because IAA gathered at the bulb center probably. ABA was decreased in every treatment, while room temperature decreased slowly than the others, 0℃ and 5℃ decreased quickly, then break the dormancy earlier. GA3 and ABA effect the ratio of(GA3/100+IAA) to ABA. Which are consistent with dormancy.3. With the increase of treatment time in each temperature, the moisture and starch content in bulb were decreased and soluble sugar was increased, and there was a significant negative correlation between the changes of starch and soluble sugar in each temperature(except the treatment of-12℃); Starch was decomposited to soluble suger in the process, which are consistent with the process of breaking dormancy and energy.4. Affected by the low temperature, SOD activity was promoted at the 4th week treatment, it falling fast, then because of dormancy breaking at 8th week. SOD activity increased, at 12 th week it kept a stable. The activity of POD changes slowly which could not show the relationship between temperature and dormancy.5. The center bub of both varieties grew most rapidly from 8th to 12 th week by the ratio of center bud height to bulb height in the degree of 0℃和 5℃, but the treatments of-12℃ and CT was decayed in stored.In green house, the rates of emergence and flowering in the degree of 0℃ and 5℃ were significantly higher than RT. So 0℃and 5 ℃were proper treatment temperatures in forcing culture of cut for tulip cultivary Golden Apeldoorn.