Study On The Effect Of Ultrasonic Treatment On The Growth Of Cultured Stachys Sieboldii Seedlings

Plant and environment are dependent on each other. Now the effect of environmental factors on the growth of plant is one of the important researches in plant physiology. The research on the effect of ultrasound on the growth of plant, compared with the electromagnetic wave, light and heat, was studied lately. It has been found that ultrasound can greatly influence the growth and development of plant. In this thesis, Stachys sieboldii Miq.seedlings were cultured and the effect of ultrasonic treatment on their seedlings was explored.In this thesis, the exterior changes of ultrasonic treatment on the cultured S. sieboldii seedlings were primarily observed. To start with the variation of the macrostructure, we primarily discussed the mechanism at the organic, cellular and subcellular level, and then went deep into the molecular level to explore how ultrasound could influence the macrostructure, microstructure, ultrastructure and gene expression. We analyze the physiological and biochemical process of plant. The main contents and results of research in this thesis are as follows.1. The effect of ultrasonic treatment could damage cultured S. sieboldii seedlings in many aspects and induce mutation. The damage of mesophyll cell is one of them, we observed and found that the leaves callus formation time of ultrasound treatment groups was shortened comparing with the control ones. However, there was no apparent difference during the later growing period, which indicated that ultrasonic treatment, to some degree, could stimulate the ability of dedifferentiation. Moreover, ultrasound could accelerate the growth of axillary buds. Ultrasound has profound biological functions. From the results of this thesis, we found with certain intensity and frequency, ultrasound could accelerate the growth of some plants and shorten the callus formation time. So we could use ultrasound to treat some plants from which we could get secondary plant substance in order to shorten the experimental period.2. The effect of ultrasonic treatment on the cultured S. sieboldii seedlings could change their submicroscopic structure. If they are treated with relatively short period of time, plasmolysis happens, simultaneously some organelles such as chloroplast and nucleus can be destroyed. However if they are treated with relatively long period of time, cell membrane can be destroyed and nucleus can be seriously distorted. Moreover,...