[Rapid Propagation in vitro of Dioscorea opposita ‘Guangfeng’and Its Stomatal Observation,FCM Analysis of Chromosome Ploidy and ISSR Detection of DNA Mutation].

Objective: To study the rapid propagation in vitro of Dioscorea opposita‘Guangfeng’, and to observe the stomas of the transplanting plantlets and potted seedlings, to test chromosome ploidy by FCM, and to detect DNA mutation by ISSR,in order to provide the technical basis for the large-scale production of Dioscorea opposita ‘Guangfeng’ plantlets.

Methods: The technique system of Dioscorea opposita ‘Guangfeng’rapid propagation in vitro was established and optimized by plant tissue culture method. The parameters of transplanting plantlets and potted seedlings were studied as follows, the stomatal parameters were observed by transparent adhesive tape method, chromosome ploidy were analyzed by FCM, and DNA mutation were detected by ISSR molecular marker.

Results: The technique system of Dioscorea opposite ‘Guangfeng’ rapid propagation in vitro was as follows, slightly woody stem segment with a bud were selected and inoculated onto MS + KT 1 mg / L + NAA 0. 2 mg / L solid culture medium and cultured in the photoperiod of 14 h / d( the temperature was( 25 ± 2) ℃ and light intensity was 1 500 ~ 2 000 Lx) after disinfected for 1 min in 70% alcohol prior to sterilized for 12 min with 0. 1% Hg Cl2,the materials were washed with sterile water for 3 times, respectively. The new bud was cut off when it grew to 2 ~ 3cm and inoculated into MS + KT 2 mg / L + NAA 0. 5 mg / L liquid culture medium and continued to culture in above culture conditions. The whole plant was formed after cultured for about 90 d. The sealing membrane was opened in transplanting, and the plantlets was still placed in above culture conditions and cultured for 2 ~ 3 d, and then the whole plant was taken out, and the culture medium washed off and then transferred into the vessel with shallow liquid MS basic culture medium and domesticated indoor. The acclimated plantlets were taken out and transplanted in the outdoor pots with the sandy soil when the new shoots grew out, and watered one time with tap water in the morning and evening per day, the survival rate reached 100%. The results of stomatal observation, FCM analysis and ISSR detection of transplanting plantlets and potted seedlings showed that the stomatal parameters, chromosome ploidy and DNA mutation of plantlets and potted seedlings had no variation.

Conclusion: The results reveal that the establishment and optimization of the technique system of Dioscorea opposita ‘Guangfeng’ rapid propagation in vitro is feasible, and the regenerated plants do not have genetic variation which can ensure the stability of the genetic.