GENE MARKERS AS DECISION-MAKING TOOLS IN GENE CONSERVATION .3. RFLPS AS GENE MARKERS FOR THE DECLARATION OF FOREST GENE RESOURCES

Using RFLPs it is now possible to analyse the genetic variation of ind ividuals directly on the level of their DNA. Like the isoenzymes, RFLP s are useful marker types for decision-making in gene conservation. Th e digestion of high molecular nuclear or organell-DNA with a restricti on enzyme often does not allow differentiation between single individu als. In such cases, it is necessary to hybridize this DNA with a radio labelled probe, which shows sufficient sequence homology to the DNA un der analysis. Especially in the fields of forest genetics research and tree improvement RFLP analysis is becoming increasingly important. Fo r example, both DNA and isoenzyme analysis of trees and seeds in popul ations of beech are being performed to give helpful information for ge ne conservation in situ. The combination of the 2 methods promises to yield a large amount of information on the genetic variation in such p opulations. With the help of DNA analysis, it will be possible to dete rmine the in most cases uniparental inheritance of the DNA from the ce ll organells. This will facilitate the study of gene flow within and b etween populations. If RFLPs are discovered in the organell-DNA, it ma y be possible to differentiate between species and hybrids between spe cies, as in the case of poplar.