A core collection enriched for Korean maize (Zea mays L.) landraces having kernel texture related morphological characters and novel multi-aleurone layer phenotypes

We have a limited number of landraces and only a few of them have been used in breeding programs. In the Korean peninsula, maize was introduced before the middle of the 16th century and cultivated widely thereafter. Over 3000 Korean maize landraces have been collected and deposited in the Genebank of the National Agrobiodiversity Center, Korea, which is about a half of total maize germplasm stored in the Genebank. The majority of Korean maize accessions have been maintained as local landraces, implying the preservation of diverse morphological traits with a wide range of variation. However, there has been a few studies for discovering phenotypic characteristics of the Korean maize landraces. We collected phenotype data of 2699 maize germplasm which can be divided by geographic origin (Korean or overseas) and breeding progress (landraces or breeding lines). Principal component analysis demonstrated that the phenotypic variations of the collected maize germplasm were largely explained by flowering time, kernel yields, and stalk diameter traits. From the phenotype data analysis, 276 accessions were selected as a core collection. We also investigated endosperm phenotypes for the core collection and found novel multilayer aleurone germplasms. This indicates that Korean landraces have maintained the original genetic variation which has largely been lost during the modern breeding programs. These findings suggest that the core collection could be a valuable resource for understating and exploiting maize germplasm. • Korean maize landraces preserved diverse traits, with 3000+ stored at the Genebank. • Flint and waxy are the two major kernel types of the Korean maize landrace. • A core collection of 276 accessions enriched with Korean landraces was selected. • Novel multilayer aleurone germplasms found in the core collection. • Korean landraces retain original genetic variation lost in modern breeding.