Immediate effects of logging on genetic diversity of Shorea curtisii (Dipterocarpaceae) revealed by DAMD-PCR markers

Ho, W. S.; Wickneswari,R.; Mahani M. C.; Shukor M. N.

Immediate effects of logging on genetic diversity of Shorea curtisii (Dipterocarpaceae) revealed by DAMD-PCR markers

2003

Ho, W. S. | Wickneswari,R. | Mahani M. C. | Shukor M. N.

Immediate effects of logging on genetic diversity of Shorea curtisii of different age cohorts. i e. seedlings, saplings and adult trees, were determined using directed amplification of minisatellite-region DNA-PCR (DAMD-PCR) markers. A total off 110 and 85 samples of S. curtisii were collected before and immediately after logging in Compartment 118, Ulu Sedili ForestReserve Johor, Malaysia. Genetic diversity parameters were estimated based on 33 reproducible fragments/DAMD-PCR loci. Two approaches were used to estimate the genetic diversity parameters, i.e. phenotypic method using Shannon's diversity index (S) and genotypic method with null-allele frequency corrected for deviation from Hardy-Weinberg equilibriumwith SSR markers. In general, the reduction of genetic diversity parameters were in the following sequence: saplings < seedlings < adults. There was a significant loss (p<0.05) of S.total number of alleles detected and mean expected heterozygosity(He) in adult trees after a single selective logging event under Selective Management System (SMS). This result is concordant with the results revealed by SSR markers (not reported here) in terms of allelic richness indicating most probably good genome coverage of both markers. The genetic distance matrix generated from SSR data was significantly correlated with DAMD-PCR genotype data (r= 0.990, p<0.05), indicating a similar genetic structure of S. curtisii being depicted by both marker types among the age cohorts tested. Therefore, in general, both DAMD-PCR and SSR markers are sensitive in monitoring genetic diversity changes due to logging and other forms of disturbance.

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