Summaries of current projects: Biotechnological Manipulation of Woody Plants for Hardwood Cutting Rooting and Growth Enhancement, and Sterility Tennessee is one of the major states in nursery crop production. The estimated annual cash receipt in 1999 was $138,000,000 (USDA). The primary crops grown in Tennessee nurseries are deciduous trees and shrubs (56%). The majority of these plants are produced by vegetative propagation, which includes cuttings, grafting, budding and tissue culture. Among these methods, propagation by cuttings, especially hardwood cuttings, is the most efficient and economical means to produce a large quantity of homogeneous plants. With this method, a section of a shoot is taken from a tree or shrub either when it is green and soft (a greenwood or softwood cutting), semi-hardened (a semi-hardwood cutting) or hardened (a hardwood cutting), then it is induced for producing adventitious roots. The rooted plant has the same genetic makeup as the mother plant, therefore maintaining the same phenotype. Using this method, hundreds of thousands of plants can be produced with expected phenotypes and homogeneity, which is desired by producers and consumers.         However, not all trees and shrubs can be propagated by cuttings, especially when trees reach maturity. With treatment by auxin and manipulation of physiological conditions of stock plants and rooting environments, many species of trees and shrubs can be propagated with softwood or semi-hardwood cuttings. Generally, a greenhouse facility with a misting system is required which needs a generous input of energy and water. The time of the year when propagation can be conducted is also restricted. A limited number of trees can be propagated by hardwood cuttings, in which a section of shoot can be taken during the winter time and roots be induced in a facility with limited protection and water input, making it the most flexible and economical propagation method. Unfortunately, the majority of woody plants and forest trees are very recalcitrant to root as by traditional hardwood cuttings. Therefore, biotechnology may overcome the problem.         Another desirable characteristic for efficient nursery crop production is to shorten the time from propagation to product delivery, which is primarily restricted by the growth rate. The growth rate also dictates the time in which a landscape plant will establish and reach mature size. Faster delivery of products from nursery to customers is commonly achieved by growing in and shipping from locations with more favorable climatic conditions and longer growing season. However, quarantine issues can restrict the movement if a disease epidemic occurs and transportation cost can be very high. Relatively little can be done genetically to speed up the maturation time for a given a tree or shrub species once it is planted, and very limited breeding work has been done to improve growth rate in ornamental trees. Therefore, the need is great to understand the mechanism of adventitious rooting and explore the possibility to speed up the growth rate in ornamental trees.         The most efficient way to develop genetic materials without altering genetic makeup in heterozygous plants is through genetic engineering. The genetic engineering employs either gene gun or Agrobacterium-based vector system, which has been used to produce many genetically improved field crops and a limited number of woody plants. One of the problems is that perennial and woody plants are often closely associated with natural ecosystem, pollens or seeds from genetically engineered plants can easily escape and intrude the ecosystem. Therefore, developing sterile plants, both male and female, is one of the means to reduce the environmental risks.