STUDY ON TECHNOLOGY OF BREEDING POLIPLOID OF Passiflora Edulis BY CHROMOSOME ENGINEERING

Experiments of producting polyploid of passionfruit (Passiflora edu]is) were made by combining chromosome engineering with plant tissue culture. In this study, the system of plant regeneration in vitro from the various organs of seedlings and adult buds of three kinds of passionfruit (yellow passionfruit, purple passionfruit, Tainong No. 1) was established. Triploid plantlets were obtained by culturing the endosperins of seeds. Induction of tetraploid by the treatment of colchicines on the seeds and callus and adventitious buds was investigated. The rule of callus induction of endosperms, buds differentiation from callus, vegetative propagation, rooting and growing successfully in soil was systematically researched. The technology on chromosome doubling by colchicines treatment was also probed. The result indicated that: Of the organs, the epicotyl and stem segment at the seedling age of 20 days were optimum explants for culturing in vitro. Adventitious shoots could be induced directly and fast with the highest frequency being 96. 7%. For induction of the adventitious bud, extra hormones were necessary. The optimum hormones combination was 3.Omg/L BA and O.2mgIL NM. The basal medium was MS with 3. O%sucrose. The optimum medium of multiplication was l/2NfS+BA2. 0 mg/L+JAAO. 2 mg/L+sucrose 2.0%. Proliferation index was as high as 7.7. The induction rate of roots was 100% at the medium 1/2MS+IBA2.Omg/L+sucrose2.0%. After proper acclimatization, the rooted plantlets were removed from culture vessels to plastic containers, and 100% survival rate was reached. When endosperm was inoculated on MS medium supplemented with BA3. Omg/L and NAA1.Omg/L and sucrose3.0%, the highest rate of callus induction (94%) was obtained. The callus looked greenish, compact and capable of redifferentiation on an appropriate medium. When the endosperm callus was transferred to the differentiation medium MS+ BA2.Omg/L+ NAAO.2tngIL, buds were regenerated from 80% callus. However, most of the regenerants were abnormal and strengthened at the medium 1/2MS+ BA2.0 mg/L+ IBAO.4 mg/L. The multiplication in vitro of endosperm plants was obtained by culturing the buds and stem segments and leaves at the medium 1/2MS+BA 2.Omg/lfNAAO.2 mg/L. Root induction was conducted by immersing the basal end of the shoot in IBA5Omg/L solution for 3. 5h. Then the shoot was transferred to the medium l/2MS+sucrosel. 5%. The rate of rooting was 85%, and the roots were good. The endospertn erived plantlets were obtained and have survived after being transplanted to soil in the green house. The chromosome ploidy was proved triploid, and the number of chromosomes was 27(2n=3x~27). The plantlets were growing successfully in soil. Studies on chromosome doubling by colchicines reated with various methods and identification of polyploid plants were reported. By gemiferous seeds and callus with green bud spots and adventitious buds treated with various aqueous solution of colchicines, polyploid plants were obtained. The callus and buds compared with seeds were better explants, the induction frequency vc~s higher, and the effect ion was better, and tetraploids were obtained. Best result for inducing tetraploids was obtained when the callus and buds were soaked in colchicines solution with the concentration 0.2% for 5d and lOd, and the frequency was 63%. When the explants were cultured in the medium supplemented with colchicines at 200mg/L for 21d, the mutation rate was 67%. The data of cytological observation showed that the tetraploids were o...