| Abstract: The plant Gynostemma pentaphyllum(Thunb.)Makino is a kind of perennial herb liane, which belongs to Cucurbitaceae. it distributing widely in China, and the wild resource is also very abundance. Across the country, a lot of provinces, such as Shaanxi, Zhejiang, Hebei have successfully cultivation.Ultrasonic irradiation is belonging to physical revulsive factor. Compare to other revulsive factors it has the advantages of cheap, convenient, natural and safe. Ultrasonic irradiation has greatly impact to plants' growth and development. Ultrasound treatment can cause chromosome damage, so it can be used in genetic and breeding research. Currently, systematic and comprehensive research on the effects of ultrasound is not deeply enough. So, it is a necessary way in the study to combining the ultrasonic irradiation mutagenesis with molecular biology, bio-engineering and other breeding approaches, in order to strengthen the mechanism and effects of Ultrasonic irradiation, and to improve the efficiency of mutation.Gynostemma pentaphyllum(Thunb.)Makino is chosen as materials in this study, we establish it's cell suspension system, then, we treat cell suspension system by the Ultrasonic irradiation in order to study the biologic effect and the impact with different treatment time to find out the changes in morphological characteristics, cellular and molecular levels. The main findings are as follows:1. the seeds of Gynostemma pentaphyllum(Thunb.)Makino can be bourgeon in biggish range from 4℃to 35℃, even in high temperature of 60℃and 80℃several seeds can still keep vim. Compare to disposes of 6-BA,GA3 and 2,4-D, Ultrasound effective enhance bourgeon rate, and the plant after treatment have no morphological variation among the periods of growth process unless under high-dose ultrasound treatment. So it is helpful to be disposed 10min use Ultrasound first before semination to field production.2. The yellow, loose, fresh callus was chosen for cell suspension culture, the optimal suspension culture system containing MS+2.4-D1.0mg/L+ 6-BA0.5mg/L. After cultivated for two weeks we got a eugenic suspension cell culture system.3. Use different ultrasonic time to treat with root tip, observe the change of chromosomes. The results show that ultrasonic can cause aberrance of chromosomes. The main aberrance types such as: micronucleus, nuclear buds, chromosomal bridges and so on can be observed. The impact and ultrasonic processing time is positively correlated. As more than 30 minutes ultrasound, aberrance is obviously strengthened, different aberrances may be found in one abnormal cell.4. Use different ultrasonic time to treat with suspension cells, the growth of suspension cells is slow down. Require a long period of adjustment to be able to enter the log phase. Meanwhile, the ultrasound treatment of long time destroyed the cell membrane cause the intracellular material spills and cell death.5. Callus tissue of Gynostemma has a certain degree of tolerance to ultrasonic treatment, low intensity ultrasonic has only slight impact to of callus tissue's differentiation rate, regeneration and modality. From 3min ultrasonic irradiation, the regeneration rate has declined, and partly callus appears browning phenomenon, simultaneity plants occur a series transformation, such as: increase of divarication, leave's abnormality, diminish of leaf and shorten of internodes.6. We use RAPD marker to study the influence of ultrasonic to regenerative plant's DNA polymorphism of Gynostemma pentaphyllum(Thunb.)Makino. In definite intensity radialization range, strips of PCR result are basically the same, however when the radialization time pass 10min, it appear relatively difference. But in general this difference can be omitted relative to the difference of different varieties. |
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