High frequency in vitro plantlet regeneration and antioxidant activity of Enicostema axillare(Lam.) Raynal ssp. littoralis (Blume) Raynal: An important medicinal plant

Objective: To develop a method for high frequency plantlets regeneration protocol for Enicostema axillare (Lam.) Raynal ssp. littoralis (Blume) Raynal (E. axillare) without intermediate callus phase and to determine the content and correlation of phenolic compounds and their antioxidant activity of both the plants derived from nature and nodal culture by DPPH assay. Methods: The nodal explants were cultured on MS basal medium fortified with different concentration of various growth regulators such as BAP, KIN, TDZ and 2iP (0.5–2 mg/L) individually and in combinations with or without GA3 for shoot bud induction and multiplication. Total phenol and flavonoid content was determined in both plants from nature and nodal culture and antioxidant activity was determined by DPPH assay. Results: The highest number of multiple shoot (108.00±3.55 shoots/explants) was obtained on MS medium supplemented with BAP (2 mg/L) in combination with KIN (0.5 mg/L) and GA3 (2 mg/L). Rooting was optimized on half-strength MS medium supplemented with IAA (0.5 mg/L). The rooted plantlets were transferred to paper cups containing vermiculite and hardening was successfully attained with 75% survival. Among the four extract of methanol and water extract from both the plantlet from nature and nodal culture, the concentration of flavonoid was found to be higher in methanol extract of the plants from nature (146.57±1.68 mg rutin/g extract) and phenol content was higher in the water extract of plant from nature (52.53±1.67 mg GAE/g extract). The radical scavenging activity of four extracts. Methanol extract of plant grown in nature showed the highest radical scavenging activity (IC50 = 87.10 μg/mL) was investigated by DPPH test. Conclusion: The present study not only enables reinforcement of wild plant populations using ex situ growth of individuals, but it also helps for high scale production of plantlets. A high correlation between antioxidant capacities and their total phenolic contents indicated that flavonoid compounds were a major contributor of antioxidant activity of both plants grown from nature and nodal culture

Genetic Diversity Analysis based on the Virulence, Physiology and Regional Variability in Different Isolates of Powdery Mildew in Pea

Powdery mildew is an omnipresent disease that reduces the yield and quality of pea crops (Pisum sativum L.). To examine the powdery mildew pathogen’s morphological, molecular, and genetic diversity, we collected samples of powdery mildew-affected pea crops from ten distinct locations in the Nilgiris district of Tamil Nadu, India. The pathogen Erysiphe pisi was identified morphologically based on anamorphic characters. Molecular identification of E. pisi isolates was befitted by targeting the internal transcribed spacer (ITS) region of rDNA and specific primers of powdery mildew fungi. The genetic variation between ten different E. pisi isolates collected from topographically distinct mountainous areas was studied using random amplified polymorphic (RAPD). Based on its morphological characteristics, the powdery mildew fungus presented high similarities to E. pisi. Molecular characterization of the ITS rDNA of E. pisi produced 650 bp nucleotides, PMITS (powdery mildew-internal transcribed region) primers produced 700 bp nucleotides, and an Erysiphe specific ITS primer pair amplified and synthesized 560 bp nucleotides. According to the findings, the collected E. pisi strains exhibited a low level of genetic diversity and only a slight differential in virulence on the host. In the study, E. pisi isolates from Anumapuram, Emerald Valley, Indira Nagar, and Thuneri showed a greater disease incidence in the natural field conditions and shared the same genetic lineage with other isolates in UPGMA hierarchical cluster analysis based on RAPD markers. There was no evidence of a link between the occurrence of the disease and these grouped populations