In vitro propagation of Tunisian local garlic (Allium sativum L.) from shoot tip culture

Purpose: Tunisian garlic is widely threatened by the attack of several viruses genus. For this purpose, a reliable protocol was established for rapid in vitro propagation of local garlic (Allium sativum L.) cultivars for large-scale production of virus-free plants and high quality bulblets. Research method: Well disinfected shoot-tips of 1 mm were used as explants and cultivated on MS basal solid media enriched with various growth regulators: 6-Benzylaminopurine, α-Naphthaleneacetic acid, Kinetin, Indole-3-butyric acid and 2-isopentenyladenine for assessment of shoot formation, shoot proliferation and bulb formation. Findings: Among the different phytohormone concentrations and combinations, MS basal medium without any growth regulators (M0) was found optimal for shoot-tip initiation (96% explants development) and plantlets elongation (56.26 mm). For shoot proliferation, the M1 culture medium containing 1 mg L-1 BAP and 0.25 mg L-1 NAA was the best, giving a multiplication rate of 1.7 plantlets/explant. Shoots on M0 culture medium formed bulblets earlier. Multiple bulblets per explants were obtained on medium M22 containing 2 mg L-1 Kin and 0.1 mg L-1 NAA. Separated bulblets were transferred individually on bulbification media. Non-dividable bulblet was developed in various sizes. Research limitations: Bulblet acclimatization step needs to be well studied for high quality cloves production. Originality/value: This efficient optimized in vitro protocol will be successfully applied for large multiplication of virus-free garlic cultivars.