Synthetic Seed Technology in Forest Trees: A Promising Technology for Conservation and Germplasm Exchange

Abstract

Forest trees are less domesticated in comparison with the agricultural plants, and even the seed produced during breeding programs is genetically diverse. The increasing global need for food and fibre results in new demands for the efficiency of wood production. The exploitation of forest area emphasizes the importance of the immediate development of conservation strategies for forest tree species. Synthetic seed technology is an advanced and highly increasing forte of plant biotechnological research. For the last two decades, intensive research efforts have been made on synthetic seed production in a number of plant species. The technique involves the use of any meristematic tissue like shoot tip, nodal segment or somatic embryo for large-scale propagation and germplasm exchange between laboratories, thus lowering the dependence on micropropagation and minimizing its relevant expenditures. In most of forest species, seed propagation has not been successful because of heterozygosity of seeds, minute seed size, presence of reduced endosperm and low germination rate. Many species have desiccation-sensitive intermediate or recalcitrant seeds and can be stored for only a few weeks or months. Under these circumstances, increasing interest has been shown recently to use encapsulation technology for propagation and conservation. The technology also provides its importance in ex vitro conservation as the encapsulation protects the plant sample from the unfavourable effects of toxic cryoprotectants and post-storage damages. After an introduction on the main procedures for synseed preparation, this chapter provides information on the protocols that have been developed for the encapsulation of various explants from forest tree species.