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

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.

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.

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.

Bulblet acclimatization step needs to be well studied for high quality cloves production.

This efficient optimized in vitro protocol will be successfully applied for large multiplication of virus-free garlic cultivars.