Study On Superior Resources Collection And Tissue Culture Rejuvenation Techniques Of Male Populus Tomentasa Carr.Trees In Beijing Area

In order to enhance the use of local resources and solve the problems of progeria,female catkins,and other issues of Populus tomentosa,the study was focused on the superior tree resources investigation,selection and rapid propagation technique.Based on the results of existing research,Populus tomentosa suitable for Beijing area were investigated and selected the male,longevity,no catkins,no premature and good landscaping effect of Populus tomentosa resources.We used superior resources of longevity and male Populus tomentosa as material to study the rapid propagation technique in order to provide technical support for the propagation of these resources on a large scale,meanwhile,the preliminary exploration of aging and rejuvenation of Populus tomentosa clones materials was also conducted.The results are as follows:1.The superior resources of longevity and male Populus tomentosa Carr.trees were chose in Beijing,including five 100?500 years old trees,three 80-year-old trees and two trees(' BJHR04'(0040)),('BJHR05'(0052))from national forest resources inventory of poplar trees.2.The best sterilization treatment was 0.1%mercuric chloride in 6min for BJHR04(0040);the 10%sodium hypochlorite solution treatment 15min was the best to BJHR05(0052);The best proliferation medium was MS+0.7mg/l 6-BA+0.01mg/L NAA for BJHR04(0040)and MS+0.5mg/L 6-BA+0.01mg/L NAA for BJHR05(0052);The best rooting medium was 1/2MS+0.01mg/L NAA for both BJHR04 and BJHR05;Humidity played a key role for transplanting seedlings,when humidity was control in 95%and the root length was control in 5 cm and above,the survival rate could reach as high as 100%.3.200 year old male Populus tomentosa Carr.tree was selected as the research object.The best sterilization was 0.1%mercuric chloride in 7 min,The best proliferation medium was MS+0.7mg/L 6-BA+0.01mg/L NAA.The better the rejuvenation effect was achieved after multiple transgenerational.The proliferation coefficient increased from 0.93 to 4.85,the percentage of plant(stem increment>3cm)increased significantly from 2.23%to 63.45%.4.It was true that there was an aging phenomenon in the propagation material of Populus tomentosa Carr.Compared to 30 year old poplar root sprout,200 year old mature tree root sprout extended the growth cycle by 40 days,the plant number(stem increment>3cm)percentage reduced by 13%.The rejuvenation effect of mature trees was much obvious than young trees when using multiple transgenerational cultivation.