Effects of drought-tolerant grapevine rootstocks on the mineral contents and fatty acid compositions of grape seeds

Abstract

BACKGROUND: As the interest in foods with positive effects on human health has increased in recent decades, the importance of the mineral contents and oil compositions of grape seeds has been better understood. However, research on grape seeds to date has largely focused on effects on health and the usability of grape seeds in the food industry and animal feeds. In agricultural research, grape seeds have generally been evaluated as a source of genes in breeding new varieties and as propagation material. OBJECTIVE: Unlike previous studies, this study not only investigates the effect of variety on the changes of pomological properties, fatty acid compositions, and oil, protein, and mineral contents of grape seeds; it also aims to determine the effects of grape rootstocks and growing seasons on those changes. METHODS: The seeds of five grape varieties (Red Globe, Trakya Ilkeren, Ata Sarisi, Hatun Parmagi, and Horoz Karasi) grafted onto drought-tolerant grape rootstocks (1103P and 110R) were analyzed during the growing seasons of 2017 and 2018. RESULTS: Seed size, moisture and oil contents, major fatty acids (palmitic, oleic, and linoleic), and levels of saturated fatty acids, monounsaturated fatty acids, unsaturated fatty acids, and boron varied by variety, rootstock, and season. However, the effects of growing seasons and varieties on the seeds were not limited to these findings; effects were also seen for seed vitality, protein content, and N, K, Ca, and Fe levels of the seeds, among others. CONCLUSIONS: Genotype was found to be the main factor causing changes in the fatty acid compositions and mineral contents of grape seeds. When the factors that we investigated were ordered based on the changes they caused for seeds in general, the sequence that appeared was genotype > growing season > grape rootstock.