Propagative Techniques And Rooting Mechanism On Dormant Hardwood Cuttings Of American Red-maple ’Redpoint’ (Acer Rubrum ’Redpoint’)

Acer rubrum imported from the United States in 2000, is tall, vigorous growth, complete crown, and its shape of leaf is beautiful. Its beautiful red leaves add infinite beauty for the autumn in the north china that makes it become important ornamental tree species. It gets more and more favor of seedling enterprises in recent years. Due to the introduction of short time, small age of mother tree, cutting seedling has become the main way of Acer rubrum breeding. Current softwood cuttings technology(such as Autumn Blaze) has obtained the certain effect, but hardwood cutting haven’t seen a report of success.More varieties of Acer rubrum, of them, Autumn Blaze introduced early in our country, but the ‘Redpointe’ is the best variety introduced late. Seeing from Propagative technique, Hardwood cutting is the most important and simple, has long growing period, and does not need complicated equipment and technology of environment control. And it can make use of the large number of branches produced by pruning and seedlings transplanting, makes little impact on the mother trees’ growth, and is an ideal way to Acer rubrum seedlings.It regarded hardwood cutting of Acer rubrum as the research object, discussed the cutting technology of hardwood cutting through screening of the matrix, treatment of auxin in detail; discusses the rooting mechanism of hardwood cutting by morphology observation and physiological and biochemical indexes testing(rooting relevant oxidases).It turns out that:(1)Hardwood cutting of Acer rubrum belongs to phloem rooting types. Adventitious roots breaks through the phloem and comes from the upper of the root cuttings soaked by the phytohormone.(2) Because it needs a long time for cuttings to take root,Perlite is a ideal medium for Acer rubrum cutting compared to wood, sand, vermiculite, loess etc.(3) Auxin treatment can significantly improve the survival rate of hardwood cutting of Acer rubrum. The rooting rate can reach 73% soaked by NAA of 2000mg·L-1 for 30 min.(4) In the process of hardwood cutting, the activity of peroxidase(POD) and polyphenol oxidase(PPO) decrease first, then increase, reduce again, and then increase, while the activity of indole acetic acid oxidase(IAAO) presents the opposite change tendency. And this corresponds to the formation of callus, root induction, and the formation of adventitious roots etc. Auxin treatment significantly changed the activity and trends of relevant oxidases.The study found out the rooting mechanism of hardwood cutting for Acer rubrum, enrich the theory of hardwood cutting, and provide technical support for hardwood cutting of Acer rubrum.