Organogenesis and evaluation of genetic homogeneity through SCoT and ISSR markers in Helicteres isora L., a medicinally important tree

Abstract

The present study develops the highly reliable and reproducible protocol for indirect organogenesis of Helicteres isora L., a medicinally important multipurpose plant of Sterculiaceae family. Murashige and Skoog (MS) medium supplemented with different plant growth regulators induced callus with different type and texture. The combination of 10.74μM naphthalene acetic acid (NAA) and 5.71μM indole-3-acetic acid (IAA) fortified with MS medium resulted best response (100%) in callus induction with fresh weight from leaf (3.75±0.11g) and internodal (3.30±0.14g) explants. Green compact nodular callus (GCNC) was transferred to shoot regeneration medium for shoot regeneration. The multiplication rate of adventitious shoots was influenced by various factors like explant type, media composition, plant growth regulator combinations and concentrations. MS medium supplemented with 2.69μM NAA, 0.57μM IAA and 4.92μMN6-(2-isopentenyl) adenine (2ip) combination resulted in 80.95±4.76 percentage of response with 8.43±0.43 number of shoots per piece of callus derived from leaf explant. This combination was expressed 76.19±4.76 percentage of response with 7.28±0.28 number of shoots per internode-derived callus respectively. The addition of 50 mg l−1 glutamine in 2.69μM NAA, 0.57μM IAA and 4.92μM 2iP combination enhanced the shooting frequency with 12.14±0.83 and 9.14±0.51 shoots from leaf and internodal explant-derived callus. Elongated shoots [4.92μM 2iP and 1.44μM of gibberellic acid (GA3)] were achieved rooting in half-strength MS medium fortified with 4.90μM indole-3-butyric acid (IBA) with 582.84μM activated charcoal. The genetic fidelity between mother plant and in vitro plants was assessed through SCoT and ISSR marker systems. Both these analysis revealed that all the samples were found monomorphic in nature. This suggests that the current study standardised the true-to-type culturing protocol and authenticated the in vitro raised plantlets are remain free from somaclonal variations.