[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.

[Study on Rapid Micropropagation in Vitro Technique of Guangfeng Medicinal Yam (Dioscorea opposita) Plantlets].

Objective: In order to provide methodology reference for virus-free and germplasm conservation of Guangfeng medicinal yam (Dioscorea opposita) plantlets, rapid micropropagation in vitro technique of Guangfeng medicinal yam plantlets was studied.

Methods: Using the method of plant tissue culture, single factor test and flow-cytometry, the basic procedure of Guangfeng medicinal yam tissue culture was established and the DNA content of Guangfeng medicinal yam plantlets and its potted seedlings was detected.

Results: The best disinfection procedure of stems with a bud of Guangfeng medicinal yam was washed with sterile water for three times after sterilized with 70% alcohol for 20 - 30 s and then washed with sterile water for three times again after sterilized with 0.

[Effect of PEG-6000 Simulation Drought Stress on Physiological Characteristics of Guangfeng Medicinal Yam Plantlets].

Objective: In order to provide the theoretical basis for the Guangfeng medicinal yam( Dioscorea opposita) in field transplanting, the effect of PEG-6000 simulation drought stress on physiological characteristics of Guangfeng medicinal yam plantlets was studied.

Methods: Using the method of spectrophotometer,the content of total chlorophyll,soluble total sugar, soluble protein and praline,as well as the activities of SOD,CAT and POD of Guangfeng medicinal yam plantlets were tested under PEG-6000 treatment.

Results: Under PEG-6000 simulated drought stress, with the increasing of drought stress and the extension of stress time, the total chlorophyll content of Guangfeng medicinal yam plantlets continued to decline, the content of total soluble sugar, proline and MDA of Guangfeng medicinal yam plantlets significantly increased, the content of soluble protein and the activities of CAT,POD and SOD of Guangfeng medicinal yam plantlets increased at first and then decreased.

[Preliminary study of Dioscorea bulbifera plantlet microtuber in vitro induction].

Objective: In order to provide a theoretical basis for the microtuber factory production and its germplasm resources preservation, in vitro induction of Dioscorea bulbifera plantlet microtubers was studied.

Methods: Through plant tissue culture technique and single factor experiment method, stems with buds of Dioscorea bulbifera plantlets as explants, the effects of various factors such as sugar, inorganic salt, cultivation mode, activated carbon and physiological state of stems with buds on in vitro induction of Dioscorea bulbifera microtubers were studied.

Results: The optimal sugar of Dioscorea bulbifera microtuber in vitro induction was 60 g/L sucrose or 90 g/L white sugar.

[Study on cryopreservation of Pueraria lobata germplasm by vitrification].

The experiment of the cryopreservation technique on Pueraria lobata showed that: At first, the aseptic explants were treated at 4 degrees C for 5 days. Then the stems with buds were cut and precultured at 4 degrees C for 1 day in 5% DMSO + 5% sucrose media. They were dehydrated with 60% and 100% PVS2 (30% glycerol + 15% glycol + 15% dimethyl sulfoxide + 0.