Somaclonal Variation in Oroxylum indicum (L.) Vent- an Endangered Tree Species

Optimum callus formation was observed from apical buds or axillary buds of in vitro grown seedling on Murashige and Skoogs’ (1962) medium supplemented with auxins 0.1-1 mg-1 of IBA, IAA, NAA and 2,4-D. Morphogenic callus was cultured on media supplemented with additives (CH & AgNO3 ) with BAP (1 mg-1). Maximum shoot regeneration  and elongation were achieved upon transferring the callus to medium containing BAP (1 mg-1) with AgNO3 (2 mg-1). Elongated shoots rooted on ½ MSM supplemented with IBA (mg-1) with AgNO3 (1 mg-1). Shoots regenerated from this protocol exhibited somaclonal variation in different characters viz. leaf shape, node size

<span style="font-size:13.0pt;mso-bidi-font-size: 8.0pt;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman";mso-ansi-language:EN-GB;mso-fareast-language: EN-US;mso-bidi-language:AR-SA" lang="EN-GB">Assessment of genetic fidelity in somaclonal variants with cytological and RAPD analysis in <i>Oroxylum indicum</i> (L.) Vent.—An endangered medicinal tree</span>

581-584Random amplified polymorphic DNA (RAPD) markers were used to verify the clonal fidelity in in vitro regenerated plants of Oroxylum indicum (L.) Vent. (Bignoniaceae). Deviation from normal/natural leaf shape and branching pattern was detected in indirectly (from callus) regenerated plants. Percentage of phenotypical variation was observed and calculated upto five subculture passages. RAPD profiles of directly (from axillary bud) and indirectly regenerated plants were compared with mother plant. To screen the genetic variation 20 arbitrary decamers were used to study of randomly selected nature grown plant as well as direct and indirect regenarants. Genetic variation among nature grown and direct regenerants was 10%, whereas 24.59% polymorphism frequency was estimated for indirect plantlets. These results indicate that the regeneration of plants through axillary bud culture is a low-risk method for generating genetic variability, whereas material regenerated through callus has genetic variation, resulting in the formation of somaclones. Cytological studies of cells of callus, root tip of directly and indirectly regenerated plants showed the incidence of polyploidy

Toxicity of Imidacloprid on Peripheral Blood Lymphocytes by MTT Assay and the Ameliorative Effect of Extract of Tinospora cordifolia (Gilloe) Extract

Imidacloprid (IMI) is a widely used insecticide which has a specific affinity for insect neonicotinoid acetylcholine receptors. Like all insecticides which are used in excess it tends to bioaccumulate in the environment. So it was thought worthwhile to study its cytotoxicity to human peripheral blood lymphocytes in concentrations ranging from 1.5mM to 4mM after 2 hours and 18 hours exposure by MTT method. Trypan blue test was also used to determine the percentage of living cells. The ameliorative effect of an extract of the stem in water and ethanolic extract of leaves of Tinospora cordifolia (Thunb.) Miers, was also studied. The viability of the lymphocytes showed a fall with increasing concentrations at an exposure of 2 hours. After 18 hours exposure to the IMI only, the viability showed a significant dose dependent drop. Trypan blue test for viability was also conducted. Addition of Tinospora extract raised the viability significantly at 2 hours of incubation. In fact this increase was greatest at 3.5mM and 4mM concentration of drug. The ameliorative effect was maximum at 2 hours. Addition of Tinospora leaf extract showed a significant increase in cell viability at 18 hours of incubation as compared to values obtained with only the drug. Thus a considerable loss of viability of lymphocytes was seen after exposure to the drug in the selected concentrations but herbal extracts seem to help to make the damage less marked. The cells showed a significant rise in viability when incubated with Tinospora leaf extract only, confirming its supportive action in cell proliferation. However, taking into account the evident fall in cell viability caused by exposure to the considerably dilute concentrations tested, caution is needed to prevent over exposure to the pesticide while spraying