The Sensitivity of Four Garlic Genotypes on Low Temperatures and the Role on Dormancy Breaking

The garlic seed bulbs cannot be planted immediately after harvest because has dormant period. Bulb dormancy can be broken by exposure of pre-planting bulbs to low temperatures. The research aimed to determine the sensitivity of different bolting types of garlic genotypes at low temperatures and the role of low temperatures on dormancy break. The experiment was conducted from March to June 2019 at the Universitas Brawijaya, using a nested design with three replications. Chinese hardneck and softneck, Sangga Sembalun and Tawangmangu Baru were the garlic accessions used in the study. The storage temperature treatments at 3 and 7°C; and room temperature at 27°C. Chinese softneck bulb had the highest sprouting and rooting after 3 and 7°C storage and was sensitive to low temperatures. The Chinese hardneck had the lowest sprouting and was highly insensitive to cold stress. Sangga Sembalun and Tawangmangu Baru had sprouted bulbs in between these Chinese genotypes, and they were insensitive and highly insensitive to low temperatures, respectively. Metabolites of 5-hydroxymethyl-2-furancarboxaldehyde, palmitic acid, diallyl trisulfide, and 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one played important roles in the bulb response to low temperature stress and directly or indirectly involved in the sprouting and rooting in dormant garlic cloves.