In situ and Ex situ Conservation of Commercial Tropical Trees - ITTO

363manan indicated that there were five loci correlated with the growth of seedlingsof that species (Salwana et al. 1996). By identifying the linkage betweenquantitative characters and isozyme markers, tree improvement programs couldbe initiated at very early ages, thus contributing to more efficient use of bothhuman resources and finances. In addition to provenance considerations,information on genetic linkage would assist conservation programs andsustainable utilization of P. falcataria by guiding development of appropriateplantation programs in Indonesia.Impact of logging on genetic diversity of S. laevis, parvifolia and E.zwageriiResults based on isozyme, RAPD, and AFLP analyses of S. parvifolia and E.zwagerii indicated that logging has not had significant effects on reducing geneticdiversity of either species. However, results suggested that it may effect futuregenetic diversity, which means that precautions must to be taken. This studyalso indicated that the three techniques used led to the same conclusion, althoughthey gave slightly different results in terms of clustering or grouping. Thedifferences found between the techniques for genetic relatedness betweenindividuals and for variation patterns of individuals within the group, werepresumably due to differences in evolution rates which affect the geneticvariation pattern (Baruffi et al. 1995). According to Williams et al. (1990) theDNA sampling region for the RAPD assay is less responsive to selection,which leads to a higher degree of resistance to mutation than DNA coding forisozymes. The different results obtained from RAPD and from AFLP wereprobably due to the result of random sampling of total genome and the result offunctional protein (Peakall et al., 1995). It is suggested that the use of thesetechniques can be applied complementary to each other. Initial analysis can becarried out using isozyme or RAPD, then AFLP may be used for further analysisto determine those groupings still not clear. Combinations of various markerswill give a better estimate of genetic correlation between individuals and couldproduce a genetic structure hierarchy based on empirical data.Results also suggest that, based on RAPD and AFLP analysis of S.parvifolia and E. zwagerii, there were no significant differences betweenlogged and unlogged areas in all parameters of genetic diversity observedalthough all values for E. zwagerii were reduced in the logged area (Table 3).Logging practices are therefore an important factor in terms of decreasinggenetic diversity in natural populations. Threshold values need to be determinedfor each species and used for implementation of appropriate conservationprograms for Indonesian species.