The Studies On Softwood Cutting Propagation Technique And Rooting Mechanism Of Tilia Miqueliana

Nanjing Linden(Tilia miqueliana) is good tree species for landscape greening,timber and nectar source. The soft cutting propagation was fist time systematicly studied for the materials of annual shoots of Nanjing Linden in this paper.The results are as follows:(1) Early Summer cutting:The test results in different concentrations of indole butyric acid (IBA):the best rooting rate for cutting treated by IBA with 1000mg·L-1 reached to 66.98%.The rooting quality for cutting treated by IBA with 1500mg·L-1 is better than the others,Which average number of roots was 10.05 for each cutting,average length of roots was 5.21cm, average diameter of roots was 0.24cm.In all, the best rooting rate for cutting keep a a complete leaf treated by IBA with 1000mg·L-1 reached to 80.00%. The average number of roots was 9.96 for each cutting,average length of roots was 5.78cm, average diameter of roots was 0.28cm. cutting in field is better than in greenhouse.Late summer cutting:the best rooting rate for cutting treated by IBA with 1500mg·L-1 reached to 60.60%. The rooting quality for cutting treated by IBA with 1000mg·L-1 is better than the others,average number of roots was 7.90 for each cutting,average length of roots was 8.04cm, average diameter of roots was 0.26cm.The rooting rate of cuttings in early summer is better than late summer.Most rootings are found in phloem or phloem- callus mixed.(2) The contents of soluble sugar,soluble protein and total nitrogen show significant changes in the process of rootings.In general, the content of nutritive substance of cuttings treated with IBA in early summer or late summer was higher than that of CK. C/N ratio theory applied to Nanjing linden softwood cutting.(3) Rooting process requires a higher level of IAA. Endogenous hormoe have synerglstic action during cutting rooting. Higher ratio of IAA/ABA and IAA/ZR is conducive to the cutting rooting.The content of GA3 and ABA on contrast cuttings is higher than treated cuttings. High concentrations of GA3 on rooting inhibit the cutting rooting(4)The exogenous IBA and NAA could increase the activity of SOD,POD and PPO in cutting. SOD can reduce lipid peroxidation. POD activity is rise in the stage of callus formation,high POD and PPO activity beneficial for the formation of callus and rooting.