| The ploidy breeding is one of the effective ways to improve traditional Chinese medicinal materials quality and breeding. The chromosome-doubled traditional Chinese medicinal materials often display the enhancement of biology output, effective ingredients content and resistance. The licorice is one kind of the large amount traditional Chinese medicines used commonly and used extremely wide.And its demand in world increases year by year, even short of demand at present. But its quality breeding advancement is extremely slow, and few has been reported.In order to obtain the high effective ingredient licorice strain, the chromosome-doubled methods of licorice and its sub-metabolizing were researched.The results were drawn as follows:1. Colchicine was used to soak the licorice dry seed and germinating seeds. Results indicated that the germinating rate of germinating seeds treated by 0.20% colchicines for two days reached to the highest level of 93.33%, and 0.05% colchicines treated dry seed for six days reached to the highest level of 76.67%.But the chimeras rate of germinating seeds treated by 0.05% colchicine for three days reached to the highest level of 34.62%, and the chimeras rate of dry seeds treated by 0.20% colchicine for four days reached to the highest level of 27.78%.But the average chromosome-doubled rate between germinating seeds and dry seeds didn't have difference, they were 36.67% and 36.48%.2. In the research of colchicine to induce the chromosome doubling in tissue culture, when hypocotyls were treated 24h, 48h and 72h by 100mg/L colchicine, the effect of chromosome doubling was the best at 72h, and the tetraploid frequency was 58.75%. But when hypocotyls were treated 24h by 50mg/L, 100mg/L, 200mg/L colchicines, the tetraploid frequency reached to the highest level of 51.25% under 100mg/L.When three explants were treated 24h by 100mg/L colchicine, the tetraploid frequency of radicles reached to the highest level of 62.50%.3. The callus induction of licorices was easy. And the MS+1.0 mg/L NAA+1.0 mg/L 2, 4-D +1.0 mg/L 6-BA was the best medium to cotyledons, hypocotyls and radicles. And all the induction rates were 100%.4. In the study of callus regeneration, only obtain the regeneration plants of hypocotyls callus,and its frequency was 4.57%.In the experiment, the best regeneration medium was MS+3.0 mg/L6-BA+2.0 mg/L ZT+10.0 mg/L GA3, and the best rooting medium was MS+1.0 mg/L IBA+13.5 mg/L KH2PO4.5. In the tissue culture of licorice, browning was general. Browned time of radicles was later than cotyledons and hypocotyls, also browned degree and browned rate was lower than cotyledons and hypocotyls. Browned degree and browned rate of young hypocotyls was lower than aging hypocotyls. The explants on low concentrations of inorganic salt browned later and browned rate was lower than those on high concentrations of inorganic salt. Dark culture could decrease callus browning degree and browned rate, 21.43% lower than light culture. In addition, the resistance browning effect of Vc was better than Na2S2O3, and 0.2 g/L Vc, 0.5g/L Na2S2O3 were the best concentrations.But the action of AC wasn't obvious.6. In the study of chromosome doubling in tissue culture, the average chromosome-doubled rate of hypocotyls reached to the highest level of 46.69%. Also all the chromosome doubling rates of cotyledons, hypocotyls and radicles callus reached to the highest under 1.0mg/L 2,4-D culturing fourty days, and they were 66.25%, 62.50% and 67.50% respectively. The chromosome-doubled effect of 2,4-D was obviously better than NAA and their combination, and the average chromosome doubling rate was 56.77%, which was 15.11% higher than NAA and 10.46% higher than their combination. Especially, the tetraploid frequency under 1.0mg/L 2,4-D was the highest,it was 59.79%.The average chromosome doubling rate of callus culturing for fourty days was higher than culturing for twenty days,and reached to 43.87%.And two plants among fourty-six were the tetraploid.7. The ability of different explants sub-metabolizing was different. The content of glycyrrhizic acid and flavonoids of glycyrrhiza of cotyledons was higher, they were 41.298mg/g and 5.931mg/g respectively. Moreover, the effect of 2, 4-D was more obvious than NAA to glycyrrhizic acid and flavonoids of glycyrrhiza accumulation, and the average content was 38.698mg/g, 5.184mg/g and 41.300mg/g, 5.450mg/g respectively. But 1.0 mg/L NAA+1.0 mg/L 2, the 4-D also promoted the accumulation of glycyrrhizic acid and flavonoids of glycyrrhiza.8. Callus chromosome doubling rate of different explants and glycyrrhizic acid and flavonoids of glycyrrhiza was positive correlation. And the correlation coefficient reached to the remarkable level (r1=0.7663*, r2=0.7643*, r3=0.7789*, r4=0.7809*), which explained the chromosome doubling rate could affect glycyrrhizic acid and flavonoids of glycyrrhiza contents. |
PDF Full Text Request