Using different phytohormones and putrescine as treatment boosters to induce regeneration from endospermic immature embryos of Allium tuncelianum (Kollmann) Özhatay, B. Mathew and Şiraneci

Abstract Tunceli garlic ( Allium tuncelianum (Kollmann) Özhatay, B. Mathew and Şiraneci) is an economically important endemic and rare plant species spread among Tunceli, (Hozat, Ovacik, and Pulumur counties), Sivas, and Erzincan provinces in Turkey. The primary goal of the study was to devise ways to induce and improve plant regeneration from Tunceli garlic immature zygotic embryos. The viability of tested seeds was confirmed through the tetrazolium test. Thereafter regeneration was further tested through culture on water agar, several concentrations of (i) 2,4-dichlorophenoxyacetic acid (2,4-D), and (ii) 6-benzylaminopurine (BAP), potassium salt-α-naphthaleneacetic acid (K-NAA), and 300.0 mg L −1 putrescine used as an elicitor or regeneration booster. These results also confirmed that seed viability level varied during growth showing nonsynchronous seed maturity in the umbels. 2,4-D induced a maximum of 20% somatic embryogenic callus using 0.3 and 1.2 mg L −1 2,4-D treatments. Paradoxically, 6.66 to 13.33% bulblet induction was noted on BAP treatments. Any concentration of BAP and K-NAA or BAP and putrescine was also suppressive and showed a reduced regeneration of 6.66%. BAP, K-NAA, and putrescine combinations were synergetic and induced regeneration potential of 10.33 and 20% bulblets per explant. The results underscore that the putrescine elicitor triggers bulblet regeneration in association with BAP and K-NAA. Putrescine failed to induce bulblet regeneration when used singly with BAP. These results have high significance and will contribute positively to understanding the regeneration of A. tuncelianum .