Physiological And Biochemical Study On Regeneration System Of All-male Plants Of Asparagus (Asparagus Officinalis L.) In Vitro

A system study of asparagus (Asparagus officinalis L.) tissue culture was carried out in this paper. Shoots in cluster were proliferated from subculturing of male asparagus axilary buds. Then the stem with one lateral bud was used as explants to study the main factors to the multiplication and rooting of asparagus in vitro.Results showed that both KT and 6-BA accelerated the proliferation of shoots cluster. The former took beneficial effect on the rate of multiplication and the quantity of the adventitious shoots. The later made the shoots chunky. The virtue was boosted up when either of they was accompanied with NAA.The kinds and concentrations of exo-hormones were the key factors that affect rooting in vitro. The inducing medium with 1.0mg/L PP333 was successful in rooting stem cuttings with the highest rate of 81.58%. Besides, Shoots number of the regenerate plants was also the biggest in this treatment. Rooting effects of 0.5mg/L S3307 was as similar as the former, the rooting rate was about 80%, with vigorous root systems and regenerate plants. Rooting rate of the treatment with 1 .Omg/L IBA were 70% approximately. Rooting percentage of BR treatment valued from the lower concentration. About half of plantlets rooted, whereas plenty of call! were produced, which did harm to rooting and root quality. The result of the study by orthogonal design showed that the optical condition for explants rooting was the inducing culture medium supplementing with PP3331.Omg/L + IBA2.0mg/L + NAA 1.Omg/L + IAA0.5mg/L+ KT0.05mg/L.The results also indicated that 1/2MS medium was much better for root induction than MS medium. 7-9 days was a suitable inducing period to initialize the adventitious roots in vitro. The apex of shoot was easier to be rooted than the mid section. The root rate of the shoots subcultured for one time was higher than that of the shoots subcultured for three times.The stems of asparagus were cultured to study the laws of biochemical characteristics during the course of plant regeneration.There were changes of different degree, however similar trend in the activities of POD, NSE and PAL. All the peaks of the activities of these three enzyme corresponded with the morphological characters during the course. There were also formed some specific bands of POD and NSE in the different stages of plant regeneration. Through analysis the change of soluble protein, DNA, RNA and endogenous polyamines, we found that the contents of them were deceased and increased significantly during the regeneration of plant in vitro. It seems that all of these changes might have close relationship with morphosis, especially the adventitious roots and vegetative buds growing.A preliminary study on anatomy of formation of adventitious roots of asparagus in vitro was also conducted. The origin position of the root was discussed.Preceding conclusions is helpful to the research of physicalmechanism of adventitious root in asparagus tissue culture.