Karyotypic Analysis of four Species of Genus Blumea (Asteraceae) from Nepal

Abstract

In this study chromosome number determination and karyotype analysis of four species of genus Blumea from the family asteraceae was carried out. The specimen plants were collected from central parts of Nepal, namely  Blumea fistulosa (Roxb.) Kurz, Blumea lacera var.glandulosa (DC.) Hook, Blumea lacera (Buem f.) DC. and  Blumea laciniata DC were observed. The chromosome number in somatic cells were recorded to be 2n= 22 in Blumea fistulosa; 2n= 32 in  Blumea lacera var.glandulosa; 2n=18 in Blumea lacera and Blumea laciniata. The range of chromosome length found to be 0.6 to 1.6 µm in  Blumea fistulosa, 0.6 to 1.6µm in Blumea lacera var.glandulosa, 0.6 to 1.7 µm in Blumea lacera and 0.8 to 1.6 µm in Blumea laciniata. Karyotype formula for Blumea fistulosa is M₁₂+ sm_{10, for} Blumea lacera var. glandulosa is M₁₄+sm₁₄+ st_4, for Blumea lacera is M₁₄+ st₂  and for Blumea laciniata is M₁₂+ sm₆ in  Blumea laciniata. In this investigation a pair of satellite chromosome found in  only one species Blumea  fistulosa at the end of shot arm of chromosome. Mainly three types of chromosomes observed in this study  having centromere at middle point, at sub-median region and at sub-terminal region. Numerical and structural variation in chromosome are evolutionary significance.  Similarity in size of chromosomes and karyomorphology indicates the homogeneity of the taxa within this tribe.

 Int. J. Appl. Sci. Biotechnol. Vol 6(2): 115-121