Bulbing Culture Of Test-Tube Seedings In Garlic And Change Of Endogenesis Hormones Content

It regarded test-tube seedings of garlic stem tip as explants,then explored the change of cultural technique of test-tube bulb in garlic.At the same time,it studied the change of endogenous hormones during the bulb formation and development,so that it provided theoretical basis and key techniques for the factory production of test-tube bulb from garlic virus-free seedings.The conclusions were as follows: 1.The micropropagation technique of test-tube bulb (1)Auxin Different concentration treatment of NAA and IBA induced bulb formation in vitro,and both had a high bulb formation rate,and the effect of NAA was superior to IBA.The medium of 1/2MS +NAA0.1 mg·L-1+IBA1.5mg·L-1 was fit for the bulb formation and development.The bulbing rate ,bulb index and the fresh weight came up to 127.78%,1.21,173.2mg respectively. (2)Ethephon The bulbing rates of different treatment of Ethephon were over 100%,1mg·L-1 ethephon treatment was the optimal one among of these treatments. As for bulb index and the fresh weight,the treatment of 3 mg·L-1 Ethephon was the optimal. (3)PP333 Within a certain range,raising concentration could inhibit the formation and differentiation of the bulb,the No.of bulb decreased,the growth of the test-tube seedings was heavily inhibited, the leaves and roots were shortened and widened. The 6mg·L-1 PP333 was the optimal treatment concentration of the inducing bulb formation and development, the bulbing rate ,bulb index and the fresh weight came up to 109.00%,1.15,307.07mg respectively. (4)SA The bulbing rates of different treatment of SA were over 100%, As for bulb index and the mean fresh weight,the treatment of 5×10-5mg·L-1 SA was the optimal, the bulbing rate ,bulb index and the fresh weight came up to 160.00%,1.16,456.77mg respectively. (5)sucrose Within the range of 30~120g·L-1,the higher of treatment concentration,the better of the bulb formation effect, 120 g·L-1 sucrose was the optimal which obtained the highest bulbing rate.As for the bulb development, 90 g·L-1 concentration was the optimal, the bulbing rate ,bulb index and the fresh weight came up to 147.78. %,1.21,368.97mg respectively. (6)AC This treatment spent longer time on bulb formation,the whole process from treatment to development was over 90d,and the bulb became round from ellipse gradually during the process of bulb formation and the development. The 3 mg·L-1 treatment was the optimal,he bulbing rate ,bulb index and the fresh weight came up to 138.89%,1.12, 391.87mg respectively. 2.The change of endogenesis hormones content in the leaf sheat and the change of relations among endogenesis hormones during the bulb formation and development (1)sucrose treatment Within the different treatment,the content of ABA rose,then decreased in the leaf sheat, the higher of treatment concentration,the much of the ABA content changed. The content of GA decreased,then rose in the leaf sheat,then decreased during the development period,but the change was not significant.The change of IAA content also rose,then decreased.Raising sucrose concentration could induce bulb formation and development,therefore,IAA was advantage for the bulb formation.The relations among endogenesis hormones were as follows:The number of GA/ABA decreased rapidly during 35d after the threatment,when came to bulb rapid development period,at first rose,then maintain stable, the relatively low number of GA/ABA was advantage for the bulb formation. The number of IAA/ABA decreased through the whole treatment process,with the change of the sucrose concentration,the number changed slightly.Therefore,the differences among treatment had a close relation with the change of the IAA/ABA,while had nothing to do with the change of GA/ABA. (2)PP333 treatment The content of ABA rose,then decreased in the leaf sheat,the increased degree was bigger during the prophase of the treatment.The change of GA content decreased during the bulb formation prophase,then maitain stable.The change of IAA content rose,then decreased,the degree of change was bigger during the 45d,when came to the bulb development period,the content of IAA maitain stable and remain a low level. The relations among endogenesis hormones were follows The change degree of GA/ABA was bigger than the sucrose treatment,the better of the bulb inducing effect was,the more significant of the number decreased.The number of IAA/ABA decreased rapidly during 35d after the threatment,when came to bulb development,the number maitain stable.Therefore,this treatment inducing bulb formation was through the decrease of IAA/ABA and GA/ABA.