Aerial bulbils as garlic alternative planting materials, a systematic review

Garlic (Allium sativum L.) is one of the world's most important Allium species for various related purposes. The commodity is commonly propagated vegetatively by using garlic cloves. This propagation type has several disadvantages such as a low rate of multiplication, a high need for storage space, persistence of viruses and other infections, and stringent sanitary standards. The accumulation of viruses when using vegetative propagation year after year can reduce garlic yields by up to 50%. As it needs high numbers of cloves, the farmers should spend considerable expenditure on input production for preparing cloves as planting materials. To reduce viral disease problems by using garlic cloves as planting materials, attempts have been established to obtain virus-free garlic cloves through the cleaning of original planting materials by using the meristem cultures. However, this procedure is costly and requires several years to obtain clean planting materials. A potential means to prepare planting materials for garlic is aerial bulbils that can be collected from garlic inflorescence (umbel). The objective of this systemic review is to provide information on an alternative approach to garlic propagation through the use of aerial bulbs or bulbils as planting materials. This systematic literature review describes the garlic flower and aerial bulb morphology, aerial bulbs as plant materials, and environmental factors that possibly promote aerial bulb production. This review hopefully helps the reader to understand the aerial bulbs or bulbils, their characteristics, and their purpose as garlic seeds.