The Primary Studies On Selection Of Self-bred Lines And Polyploid Breeding Of Garden Balsam (Impatiens Balsamina L.)

Garden balsam (Impatiens balsamina L.) is a famous annual plant originated in China. It has a long cultivation history and widely planted from south to north China. However, it has not been fully used in the landscape architecture. Researches on garden balsam were focused on its medical functions, and limited studies were carried out on its breeding. In this study, 16 varieties of Garden balsam were used to obtain pure lines by pedigree method. Tetraploid plants were gained by treating garden balsam seeds and young plants with colchicine and these tetraploid plants can be used as interspecies cross materials. The main studies were as following:1 Selection of self-bred lines and some relative research1.1 29 self-bred lines were obtained by self-pollination after different generations, and most of the inbred lines were pure while self-bred lines with color variegation on petals were not pure.1.2 Biology characters of flowering were observed and analyzed. No difference of pollen vitality was detected in a day for four inbred lines. When pollen was preserved at 25℃, in desiccator at 25℃ and in 4℃ refrigerator, respectively, there was no significant difference on pollen vitality. However, vitality of the pollen preserved under these three conditions all decreased considerably with the time, and 24 days later, pollen vitality was 8.7%.1.3 According to the comparison of 10 traits of 26 inbred lines, principal component analysis and correlation analysis had been done. The result showed that the plant height, plant crown, leaf length, leaf width, flower size, length /width of leaf indexes are the major characters. There was no discrepancy during most of the character of garden balsam. This result showed that more traits should be selected in order to obtain good varieties2 Induction of polyploidy: Germinating seeds of garden balsam were dipped in 0.1%, 0.3%, 0.5% colchicine solutions for 6h, 12h, 24h, 48h. Treatment with colchicine solution at 0.1% for 6h gave the best results. According to the results of the seeds, treatment with colchicines drops was used to do with stem tip. The concentration of colchicines of 0.05%and 0.10% with 4 days and 0.15%, 0.20% with 3 days were chosen to deal with stem tip with a pair of main leaves. It was observed that compared with normal plants, the mutant plants showed the following features: thicker leaf, longer serrated denticle, change of blade profile and large stomata size. Examination of flow cytometry revealed that that they were either tetraploid or chimeras in mutant plants. According to the Anova analysis,...