Biotechnology in lilies - dreams vs. reality.

摘要

Biotechnology can be defined as any technological application that uses biological systems, living organisms or derivatives thereof to develop or modify processes for a specific use. Biotechnological techniques have been used by the horticultural industry for both propagation and breeding. Lilies were among the first floricultural crops for which tissue-culture methods were introduced for rapid propagation of new cultivars and valuable plant material, as well as production of virus-free stocks. Plant breeders use in vitro techniques such as embryo rescue, ovary-slice culture, ovule culture and protoplast fusion, to overcome compatibility barriers and generate interspecific hybrids. Recently, biotechnology is used in conjunction with molecular markers and genetic engineering. Lilium has been transformed using both Agrobacterium-mediated and microprojectile-acceleration methods. The purpose of these methods is the insertion of commercially valuable genes that are not known to be present in Lilium. The success of the transformation in both systems depends upon the successful assembly of several key components and the calibration of the entire system. One component is the availability of a genetic construct carrying a target gene, a reporter gene and an appropriate selectable marker, all under the control of appropriate promoters. A second component is the plant organ or tissue, which must be competent for genetic transformation. That is, it must be capable of interacting with the gene-delivery system and accepting the foreign DNA, incorporating the newly acquired DNA into its own genome, expressing the genes and maintaining the ability to regenerate into plants. Although several valuable genes are available and the transformation systems are well calibrated, very few attempts to produce genetically engineered lilies with commercially valuable traits have been successful and none, to date, have resulted in a registered lily cultivar. Marker-free technology is needed to overcome obstacles in cultivar registration and ease the risk-assessment process. In order to be commercially viable, any genetically engineered cultivar would also have to be free of any patented technology or, alternatively, contain only proprietary technology covered by freedom-to-operate agreements. Public concerns also have to be addressed before a new transgenic lily can be commercialized.