Study On Concentration Depth Distribution Of Ions Implanted Into Plant Seeds With Low Energy

Since Yu. Z. L et al initially developed a study on mutation breeding of heavy ionimplanted in rice in the 1986, Ion Beam Biotechnology has already made importantachievementes and brought better economic profits. But the mechanism of interaction ofions implanted in bio-materials is still not well known. It should be further studied. Atfirst, the distribution and precise location of ions implanted into bio-material should bediscussed.In this paper the study of distribution of ion beams implanted in plant seeds wasdeveloped. The thesis includes four chapters. The chapter one summarized the presentstatus of domestic and foreign studies on the ion-beam-engineering, the progress ofinteractive mechanism of ions implanted in bio-materials and the study of mutationbreeding of Ion Beam Bio-technology in crop seeds and microbes. Since the specialstructure of plant seeds could make the penetration depth much larger as ion beamsimplanted, we gave a brief introduction on the structure of plant seeds in this chapter. In chapter two, based on the fact that the plant seeds have many small gaps or holes,we proposed a simplified model. Many small holes have different length and width,they are not homogeneous in biological samples. They were thought of cylinders, namedchannels, in this paper. These small holes could cause channel phenomenon, enlargingpenetration range of low energy ion beam implantated into plant seeds.In chapter three, considering the implantation depth influenced by channels, wecalculated the implantation depth by use of LSS theory. AssumingV~+ implanted inpeanut seed embryoes with 200kev, the projective penetration depth was calculated. Theconcentration distribution of V~+ implanted in peanut embryoes was fitted with statisticalmodels.In chapter four, the calculation results are outlined. We obtained the averagepenetration depth 5.32μm for V~+ implantation into peanut seed embryoes, in consistentwith experimental data. Simultaneously we found that the concentration distribution of V~+ions in seed embryoes approximately obeys Gumbel distribution.