In vitro effect of phytosynthesised AgNPs to enhance plantlets and biomass production in Nyctanthes arbor-tristis L.

Abstract

This work was aimed to establish an effective approach for direct regeneration of Nyctanthes arbor-tristis L. using nodal segment. Amongst the different combinations of plant growth regulators (PGR's), the maximum number of shoots/explant (32.94 ± 0.86) with 3.14 ± 0.08 cm shoot length was attained on Murashige and Skoog (MS) medium fortified with 3.5 mg /L 6-benzyladenine (BA) and 0.3 mg/L concentration of 1-phenyl-3-(1, 2, 3- thiadiazol-5-yl)- urea (TDZ). Besides, nodal segments of Nyctanthes grown on MS medium were used to analyze the effect of biogenic AgNPs (0,2,4,6,8 and 10 mg/L) on plant growth & multiplication in solid & suspension culture medium. After 35 days of in vitro shoot proliferation, the shoot number, shoot length, chlorophyll content, fresh & dry matter, guaiacol peroxidase (GPOX) and catalases enzyme (CAT) activities of plants were quantified. The administration of AgNPs (6 mg/L) along with the lower concentration of BA (1 mg/L) could enhance shoot multiplication from (1.29 ± 0.14) to (25.17 ± 0.45), chlorophyll content as well as the GPOX, and CAT enzyme activities in suspension culture medium. Optimized rooting response (12.15 ± 0.63) was noted on the half-strength MS medium supplemented with 0.5 mg/L concentration of Indole acetic acid (IAA), The maximum in vitro raised plantlets was hardened & acclimatized in a ratio of 6:2:2:1(garden soil: cocopeat: vermiculite: pearlite) potting mixture. The regenerated plantlets showed 80% survival rate under greenhouse conditions. Out of twenty PCR-based RAPD (Random Amplified Polymorphic DNA) molecular markers, 8 primers produced a total of 350 scorable bands which showed 90–99% similarity with mother plant.