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

• Effective reproducible adventitious shoot regeneration protocol has been standardised
• 2ip was found suitable to enhance the adventitious shoot regeneration in callus tissues
• Shunted microshoots were recovered then successfully elongated into well-developed shoots
• SCoT and ISSR genetic marker systems were employed to ensure genetic fidelity of regenerants from somaclonal variation

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 10.74 μM naphthalene acetic acid (NAA) and 5.71 μM indole-3-acetic acid (IAA) fortified with MS medium resulted best response (100%) in callus induction with fresh weight from leaf (3.75 ± 0.11 g) and internodal (3.30 ± 0.14 g) 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 2.69 μM NAA, 0.57 μM IAA and 4.92 μM N6-(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 2.69 μM NAA, 0.57 μM IAA and 4.92 μM 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 [4.92 μM 2iP and 1.44 μM of gibberellic acid (GA3)] were achieved rooting in half-strength MS medium fortified with 4.90 μM indole-3-butyric acid (IBA) with 582.84 μM 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.