Study on tissue culture juvenation technique of male Populus tomentosa Carr
[Objective]Regeneration of Populus tomentosa mainly rely on asexual reproduction,but the material of asexual propagation often has aging phenomenon.[Method]It is important to understand the aging pattern of reproductive material and the juvenation techniques.In this study,200 year old mature trees of male P.tomentosa root sprouts were used as study materials.Two sterilization reagents and sterilization times were used to test the impact on the survival rate and growth of propagules.Different hormone combinations in MS medium were designed to select the best multiplication culture medium according to the effect of propagule proliferation.Juvenation technique of mature P.tomentosa were studied through successive sub-culture.[Result]The results showed that sterilization effect of 0.1%mercuric chloride solution was better than the 10%sodium hypochlorite solution.The best sterilization treatment was 0.1%mercuric chloride in 7 min,the highest survival rate was 57%.The best proliferation medium was MS+0.7 mg/L 6-BA+0.01 mg/L NAA,in which shoot multiplication coefficient was the highest of 2.23,the proportion of shoot number(shoot increment≥1 cm)was 53.33%,they were significantly higher than other mediums.After 4 generations of breeding the growth cycle decreased from 63 days to 44 days,the proliferation coefficient increased from 0.93 to 4.85,the percentage of plant number(shoot increment≥3 cm)significantly increased from 2.23%to 62.34%.[Conclusion]It was indicated that there was an aging phenomenon in this 200 years old P.tomentosa root sprout.The juvenation effect was much obvious after multiple sub-cultures.
tissue culturemature treesphysiological agingjuvenationmale Populus tomentosa Carr