Journal of Horticulture and Postharvest Research

Abstract Purpose: Despite the significance of garlic as a food product and high annual income, until now there are no local commercialized Tunisian cultivars with registered names, which lead to the lack of recommended varieties of high yielding. This work is aimed to create the first garlic gene bank collection in Tunisia, evaluate the variation, identify yield related traits and structure genetic diversity among them. Research method: Thirty six local garlic landraces from the main production regions of Tunisia were collected and recorded in the National Gene Bank of Tunisia database, then grown in a gene bank field for multiplication. The phenotypic diversity was conducted on the basis of fourteen quantitative characteristics add to flowering ability. Findings: High diversity among Tunisian garlic landraces was detected. The bulb weight and bulb diameter explain the most significant variation of the yield. The cluster analysis sorted the 36 genotypes into three main groups as cluster 1 (11 accessions), cluster 2 (20 accessions), and cluster 3 (5 accessions). However, the grouping of genotypes did not correspond with their geographic origin. The highest genetic distance was reported between NGBTUN442 and NGBTUN452, however NGBTUN429 and NGBTUN434 found to be most similar with the lowest dissimilarity. Research limitation: Morphological traits need to be investigated overtime. Originality/Value: This study is interesting since it presents the first creation of the garlic gene bank in Tunisia. The results will provide basis information for the efficient use of the local garlic germplasm and help breeders to easily select out the desirable materials.

Abstract 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.