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

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+ sm10, for Blumea lacera var. glandulosa is M14+sm14+ st4, 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.


Introduction
In the present study four species of the genus Blumea , namely Blumea fistulosa, Blumea lacera var.glandulosa and Blumea laciniata from the asteraecea family collected from Central Nepal was Cytologically carried out.The genus Blumea is a flowering plants belonging to the family Asteraceae.The plants of this genus Blumea are mostly small weeds.Many species of this genus are used in traditional Chinese medicine and also used in ornamental plants.The genus Blumea locally called Kukur ghaans in

Materials and Methods
The plants were collected from Central parts of Nepal, brought to Kathmandu and transplanted in earthen pots at my home garden.Somatic chromosomes were observed in the meristamatic cells of root tips for karyotypic analysis.To ensure full turgidity, plants were sufficiently watered for

Research Article
two hours before the excision of the root tips for pretreatment.Healthy root tips were pretreated in aqueous solution of 0.002M 8-hydroxyquinoline for three hours.They were then fixed in a mixture of absolute ethanol and glacial acetic acid (3:1) for one day or more.In the laboratory root tip materials were hydrolyzed and stained in a mixture of 2% aceto-orcein and 1N HCl (9:1) contained in watch glass and warmed for few seconds and left for 30 minutes to 1 hour.Squashes were made in 45% acetic acid.The observations were done from this preparation to select the plates for photomicrography.The drawings were made at table level using opcolite-1366 Camera Lucida apparatus.Photomicrographs were taken with the help of digital camera of 12.1 megapixel using 10 x eye pieces and 100x objective of trinocular compound microscope.The methodology was followed according to Levan et al. (1965).
Chromosome number determined for this taxon is 2n=22.The somatic chromosome number determined from the root tip cell is shown in (Fig. 1B) and camera lucida drawing in (Fig. 1C) 3. Its ideogram is represented in (Fig. 1D).The chromosome measurements are given in Table 1, The karyotype consists of two different types of chromosomes with centromere at median point and submedian region.The chromosome length ranged from 0.6 to 1.6 µm with mean length 1.0 µm and absolute length 12.0 µmTF % is 45.0.Karyotype formula is M12+ sm10.Chromosome number presently determined for this taxon is 2n=32.The somatic chromosome number determined from the root tip cell is shown in (Fig. 2B) and camera lucida drawing is in (Fig. 2C).Its ideogram is represented in (Fig. 2D).The chromosome measurements are given in Table 2.The karyotype consists of three different types of chromosome with centromere at median point, sub-median region and sub-terminal region.The chromosome length ranged from 0.6 to 1.6µm with mean length 0.9 µm and absolute length 8.4µm.TF % is 39.2.Karyotype formula is M14+sm14+ st4.
Chromosome number determined for this taxon is 2n=18.
The somatic chromosome number determined from the root tip cell is shown in (Fig. 3B) and camera lucida drawing is in (Fig. 3C).Its ideogram is represented in (Fig. 3D).The chromosome measurements are given in Table 3.
The karyotype consists of two different types of chromosomes with centromere at median point and subterminal region.The chromosome length ranged from 0.6 to 1.7 µm with mean length 0.9 µm.and absolute length 8.4 µm TF% was 39.2.Karyotype formula is M14+ st2.
Chromosome number determined here for this taxon is 2n=18.The somatic chromosome number determined from the root tip cell is shown in Fig. 4B and camera lucida drawing in Fig. 4C.Its ideogram is represented in Fig. 4D.The chromosome measurements are given in Table 4.   Mathew and Mathew (1975).This is the case of intraspecies variations among the taxa.Chromosome number for Blumea laciniata 2n=18 tallies with Peng and Hsu (1977) and Sharma (1970).The various numbers found for this species are due to the existence of different cytotypes.In present investigation chromosome bearing satellite is observed in only one species Blumea fistulosa of the tribe Inuleae.A pairs of satellite observed in short arms of the chromosomes in this taxa.Satellite, play a significant role in the study of karyotypes (Sakya, 1991).All four species of Blumea studied presently from the tribe Inuleae found to be polyploid forms.B. lacera var.glandulosa (2n=32) has been found to be descending pentaploid form of base number x=7.B. lacera (2n=18) and B. laciniata (2n=18) have been found to be descending triploid forms of base number x=7 in present study.Basic numbers x= 8, 9, 10, 11 are observed by Peng and Hsu (1978) for this genus.Similarity in size of chromosomes and karyomorphology indicates the homogeneity of the taxa within this tribe.

Table 2 :
Chromosome measurement in Blumea lacera var.glandulosa (DC.)Hook The plant is an annual herb, slender, very variable weed with a strong turpentine or camphor odour, 45-60 cm high.Stem erect, simple or branched, covered with hairs and glands (Fig.2A) often grey in more silky forms.Leaves alternate, petiolate, obovate, margin toothed; heads in short axillary cymes and collected into terminal panicles,
Among the four species of genera Blumea from the tribe Inulae, the length of chromosomes ranged from 0.6 to 1.6 µm in B. fistulosa, B. lacera var.glandulosa, B. laciniata,