Molecular phylogeny of dipetrocarpaceae in Southeast Asia based on nucleotide sequences of matK, trnL intron, and trnL-trnF intergenic spacer region in chloroplast DNA

To obtain a refined molecular phylogeny of dipterocarp species in Southeast Asia, nucleotide sequences of matK, the intron of trnL, and intergenic spa cer region between trnL and trnF in chloroplast DNA were determined in 16 s pecies throughout 10 genera. In the resultant trees Southeast Asian diptero carp species were divided into two clusters. One cluster consisted of Aniso ptera, Vatica, Cotylelobium, and Upuna, all with the base chromosome number of x = 11. The second cluster consisted of Hopea, Shorea, Neobalanocarpus, Dryobalanops, Parashorea, and Dipterocarpus, mostly with the base chromoso me number of x = 7. Dipterocarpus was the only genus that had the base chro mosome number x = 11 in the latter cluster. This result suggests that the c hromosome number changed from x = 11 to x = 7 after Dipterocarpus branched in the latter cluster. Other evolutionary changes of morphological characte rs are also discussed. (C) 1998 Academic Press.