Studies On Rapid Micropropagation And Cutting Technique And The Rooting Mechanism Of Potentilla Fruticosa L.

Potentilla fruticosa L. has excellent aspects on flower type and flower color, as well as quite long flowering period, which make it would be a good frutex strain that can be used in garden; Potentilla fruticosa L. has strong root and excellent cold-resistance and drought-resistance abilities, which provide it highly water-soil-preserved function; Potentilla fruticosa L. is good material of chemic industry because its leaf and fruitage contain tannin which can be distilled latex; Potentilla fruticosa L.'s flower is fine antipyretic as well as anti-hotness medicine. The spinney has plenty nutrition, which is good forage. Also, Potentilla fruticosa L. is used to be architectural material by Tibetan. Therefore, Potentilla fruticosa L. is a kind of good wild plant resource which has highly exploitation value. However, the quantity of seedlings which gained by seed and burgeon is finite and can't satisfy the demand of market. Consequently, the rapid micropropagation and cutting technique and the rooting mechanism of Potentilla fruticosa L. were comprehensively studied in this .paper, which intended to get the effective ways of improving its quantity and quality. Taking Potentilla fruticosa L. as materials, this experiment studied the whole process of tissue culture from the establishment of germfree system, start-up culture, multiplication and strengthening seedling culture to the radication and transplantation; as well as the promotion of exogenous regulators treatment in cutting rooting of soft wood and hard wood, the variation of nutrients and enzyme activity during rooting. The paper also analysed the mechanism of cutting rooting of Potentillafruticosa L. and got the following results:1. The best time of extraction is the last ten-day of April, the bud is just grow in this period, the contaminated rate(15.00%) and death rate(19.61%) are the lowest, and the survival rate is higher; The best result of sterilizing agent is 70% alcohol(15s)+0.1% HgC12 (4min)+Tuwen, Who's contaminated rate is 40.63%,and survival rate is 53.13%. The optimal start-up culture medium is MS+6-BA2.0 mg/L + NAA0.1 mg/L.2. The result indicated that WPM is the most suitable macro-element. The optimal medium for shoot growth is WPM +6oBA 2.0 mg/L + KT 0.05 rag/L; And the most favorable medium for bud multiplication is WPM +6-BA 2.0 mg/L +KT 0.05 mg/L +IBA 0.2 mg/L.3. The axenic seedlings grew best in WPM media during the seedling strengthening period, which had extended green leaves and grew vigorous. The optimal medium for seedling strengthening is WPM +6-BA0.05 mg/L + NAA0.2 mg/L. 4. The optimal rooting medium is 1/2MS + NAA0.1 mg/L with 10 g/L sucrose on the basis of rooting index. Cell fissive element is not furthersomefor rooting, and growth regulator NAA plays a important role for the rooting of seedling, but the concentration of sucrose is not a main parts of rooting medium.5. Study found that IBA can promote hard wood cuttage rooting rate(75.57%), as well as ABT-7 for soft wood cottage(92.83%).And the best treatment concentration of ABT both for hard and soft wood cuttage rooting rate was 500 mg/kg, but 1 000 mg/kg made root grew longer. Treatment of 1/4 hour for soft wood cuttage showed the highest rooting rate, and the number of roots was most in 1/2 hour treatment. The best root-promoting agent of soft wood cuttage was the cuttings from basal region of branch.6. By the correlation analysis of rooting rate and the activity of enzyme, the rooting rate had negative correlation with the activity of IAAO, and positive correlation with the activity of PPO,POD in soft wood cuttage .Both IAAO and POD can oxidize IAA, they effected the rooting rate through adjusting the content of endo-hormones, but PPO effected the cuttage rooting rate through catalyzing IAA-Hydroxybenzene -Acid.7. Soft wood cuttage rooting rate showed positive correlation with the total carbon content and C/N, but showed negative correlation with the total nitrogen content. The treatment of regulators raised the total carbon content and the C/N, also decreased the total nitrogen content, so they can promoted rooting rate.