Wednesday, November 15, 2006

Optical Quantification Techniques for Plant Genetic Characterisation.

Lene K. Christensen and Bent Skovmand. The Nordic Genebank, P.O. Box 41, S-230-53 Alnarp, Sweden

Plant genetic variation is essential for long term survival of a population. The larger the variation within a population the more likely it is that some members of the population will survive dramatic changes in the environment. Nature is the largest gene bank of plant genetic resources; it conserves the genetic variation, but may change. Ex situ gene banking is the practice of protecting cultivated plants outside of their native habitat. It is a way of maintaining plant genetic variation even though it would not have been able to survive in its natural or cultural origin. The goal of conserving plant genetic material is not just to ensure survival of the “un-fittest”! It is also provide the possibility to utilise our plant genetic heritage. Characterisation is a prerequisite for utilisation of our plant genetic resources.  Many studies of genetic diversity in plant species has been greatly facilitated by the development of new methods. Thermal and spectral imaging are two potential, advanced techniques for fast and non-destructively identification of relative variation within biological material. Quantification of diversity in biological material can be done through infrared thermometry and spectral reflectance recordings. Thermal and spectral recordings reveal temperature and reflected light of a specific target region, respectively. The two techniques allow visualisation of differences in surface temperature and reflected light by detection of emitted radiation. Computer software transforms these radiation data into thermal and spectral intensity levels. These relative intensity levels are signatures of the architecture and physiology of the biological material, thus indicating genetic structures among population, species or accessions. We find that these two non-destructive and fast quantification techniques have promising potential in identification of plant genetic variation in many aspects and could in the future replace the initial investigations at molecular level.