Effects of Droplet-Vitrification Cryopreservation Based on Physiological and Antioxidant Enzyme Activities of Brassidium Shooting Star Orchid

Protocorm-like bodies (PLBs) of Brassidium Shooting Star orchid were successfully cryopreserved using droplet-vitrification method. Vitrification based cryopreservation protocol is comprised of preculture, osmoprotection, cryoprotection, cooling, rewarming, and growth recovery and each and every step contributes to the achievement of successful cryopreservation. In order to reveal the lethal and nonlethal damage produced by cryopreservation, histological observation, scanning electron microscopy (SEM), and biochemical analysis were carried out in both cryopreserved and noncryopreserved PLBs of Brassidium Shooting Star orchid comparing with the control PLBs stock culture. Histological and scanning electron microscopy analyses displayed structural changes in cryopreserved PLBs due to the impact of cryoinjury during exposure to liquid nitrogen. Total soluble protein significantly increased throughout the dehydration process and the highest value was achieved when PLBs were stored in liquid nitrogen. Ascorbate peroxidase (APX) and catalase (CAT) showed the highest enzyme activities in both dehydration and cryostorage treatments indicating that stress level of PLBs was high during these stages

Potential antioxidant activities of methanolic extracts of Spider lily (Hymenocallis littoralis)

Abstract Hymenocallis littoralis has allelochemical importance such as defensive compounds, insect repellents, attractants, and their role in ecological balance. Antioxidant activities of Hymenocallis littoralis bulb, anther, flower, stem, leaves and root methanolic extracts were evaluated using Ferric Reducing Antioxdiant Power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), total phenolic and flavonoid assays. Dried parts were ground and extracted using sonication method. The extracts were then tested for their antioxidant activity by FRAP, DPPH, total phenolic and flavonoid assays. The flower and anther methanolic extracts shows ferric reducing antioxidant power (FRAP) at 555.12 ± 1.67 and 568.09 ± 0.42 µmol g -1 Fe 2+ . High activity for DPPH free radical molecules was observed in flower (1.29 mg mL -1 ), stem (1.33 mg mL -1 ), and anther (0.31 mg mL -1 ). The phenolic content of Hymenocallis littoralis extracts are in ascending order as per root < leaves < stem < bulb < flower < anther. The flavanoid content of Hymenocallis litoralis plant extracts in ascending order are bulb < root < leaves < flower < stem < anther. Elucidation and isolation of the active compounds from this plant can help to shed more information of the compound of interest. This finding shows that the Hymenocallis littoralis bulb, root and anther extracts possess a good antioxidant activity which can demonstrate a better cytotoxicity activity

Effects of plant growth regulators and activated charcoal on somaclonal variations of protocorm-like bodies (PLBs) of Dendrobium Sabin Blue orchid

Protocorm-like bodies (PLBs) of Dendrobium orchids are emerging as a potential source of valuable secondary metabolites. This study examined the effect of four additives namely 1-naphthaleneacetic acid (NAA), kinetin, thidiazuron (TDZ), and activated charcoal (AC) used in culture medium on genetic variability in PLBs of Dendrobium Sabin Blue. Nine (9) ISSR primers and eleven (11) DAMD primers were used to assess the genetic variability of PLBs that were subcultured over a period of two years. We confirmed that the use of kinetin in culture medium for two years resulted in the highest rate of somaclonal variation in PLBs. On the other hand, TDZ and activated charcoal registered the lowest genetic variability in PLBs. The findings of this study suggest the importance of selecting additives used in the culture medium to maintain stable genetic lines of PLBs. We recommend that the assessment of somaclonal variations should be performed for long term maintenance of tissue cultures