Comparative cytological studies of naturally grown plants and in vitro grown plants of Gynura procumbens – an important medicinal plant species

Abstract

Summary Introduction: Gynura procumbens is an important medicinal plant that contains different types of chemical constituents that show tremendous curative effects. Objective: The aim of this research work was comparative karyomorphological analysis between in vitro and in vivo grown selected medicinal plant species. Methods: The roots were collected properly from naturally grown plants and in vitro propagated plants and pretreated with 1,4-para-dichlorobenzene (PDB) for 2.00 – 3.00 hours at room temperature. After pretreating with PDB the roots were washed thoroughly and kept in 1:3 (v/v) aceto-alcohol for 24 hours and then, transferred to 70% alcohol (v/v) for preservation. After that completing staining process, prepared slides were observed under microscope for karyotype analysis & ideogram preparation. Results: This research work reveled that both mother plant and tissue culture raised plants had 2n=20 chromosomes in somatic cell. No telocentric or acrocentric chromosome observed in the basic set of chromosomes. Both plants had 3 submetacentric and 7 metacentric chromosomes in the basic set of chromosomes. The centromeric formula for both plants was 3sm + 7m. The length of individual chromosome of in vivo plants ranged from 6.20 to 11.24 µm, whereas chromosome length of in vitro grown plants ranged from 6.08 to 11.22 µm. The total form percent (TF%) of naturally grown plants and micro-propagated plants were same (43.93%). Mother plant had 2A type of karyotype, the formula being 2Lsm + 4Msm + 4Mm + 10Sm. In vitro grown plant had also 2A type of karyotype which could be expressed by the formula, 2Lsm + 4Msm + 2Mm + 12Sm. Conclusion: The results of cytological studies point out that chromosome numbers of naturally grown plants and micro-propagated plants were same. There were very little karyotypic variations observed in case of both micropropagated and mother plants.