A karyotype analysis on acacia auriculiformis

The karyotype and chromosome number of A cacia auricullformis,wereanalysed on meristematic cell of root tips.The resuIt showed that the chromosome numberin each somatic cell was 2n=26.THe 10 pairs of chromosomes (No.1,3~5,7,9~13)were metacentric, and the 3 pairs of chromosomes(No. 2,6,8)were submetacen-tric. the lst through 3 rd of pairs(No.1~3)were SAT-chromosomes.According to theclassification made by Levan et al, the karyotype f ormula is k(2n)=26=20 m (4 Sat)+6Sm (2Sat). Accoding to the ration of chromosome length (length largest/smallest)and the pro-portion of chromosomes with arm ratio > 2 in the complement,the karyotype of Acacia auriculiformis belongs to Stebbins' "2B" of karyotype symmetry.