Morphological, Phytochemical and Molecular Characteristics of NSIC-Registered Varieties of Garlic (Allium sativum L.) in the Philippines

Background: Garlic belongs to the largest monocot genus, Allium, comprising different species known for their use as spices and medicinal plants. It ranks second in volume and area of production among the Allium species, next to onoin. The Philippines is renowned for garlic varieties with a strong and pungent odour observed in the seven accessions registered at the National Seed Industry Council (NSIC), Department of Agriculture, Philippines. Morphological, phytochemical and molecular characterization of the different garlic varieties would provide baseline information important to the identification of the registered varieties, their conservation and improvement. Methods: Physiologically mature and disease-free NSIC-registered garlic accessions were characterized and evaluated at the Institute of Crop Science, University of the Philippines Los Baños. The bulbs were separated from each other and planted in a homogenous field. Morphological characterization was done from the vegetative stage until bulb harvesting using an Allium spp. descriptor list. The mature bulbs of each accession were screened for phytochemicals and alliin content. SSR markers were used to fingerprint the eight garlic accessions. Result: Qualitative characters showed low diversity (H’ = 0.22), while quantitative characters had intermediate diversity (H’= 0.51). Identical phytochemicals, flavonoids and phenols, were detected across all the garlic accessions. Despite this, alliin content varied considerably with Bang-ar and Mindoro having the highest (37.70±0.70 mg/g) and lowest (17.22±0.68 mg/g) alliin contents, respectively. Only one SSR primer, ASA-24, showed polymorphic bands that can discriminate Batanes White and MMSU Gem from the other NSIC-registered garlic varieties.