A comparative study of chromosome characters in four species of Elsholtzia Will. (Lamiaceae) in Japan and China

Abstract

Four species of Elsholtzia such as E. flava Benth., E. penduliflora W. Smith, E. ciliata (Thunb.) Hyl. and E. nipponica Ohwi had the common chromosome characters at the resting stage classified as the complex chromocenter type. Elsholtzia flava and E. penduliflora had the common chromosome number as 2n=20, while E. ciliata had the chromosome number of 2n=32 and E. nipponica had the chromosome number of 2n=16. The chromosome numbers of 2n=16 and 32 were considered diploid and tetraploid, respectively if the common basic chromosome number was x=8, while the chromosome number of 2n=20 could be diploid if the basic chromosome number was x=10, respectively. The chromosome numbers of 2n=20 for E. penduliflora and 2n=16 for E. nipponica were reported here for the first time. The karyotypes of the four species described here had commonly monomodal gradation in chromosome length from the largest to the smallest chromosomes, and showed median-, submedian- and subtermina- centromeric chromosomes in E. flava and E. penduliflora, and median- and submedian-centromeric chromosomes in E. ciliata and E. nipponica.