Geographical regions and genetic variation of SAD2 gene affect olive oil quality of ‘Mari’ and ‘Shengeh’ cultivars

This study was conducted to compare qualitative properties of olive oil produced from two endemic cultivars of ‘Mari’ and ‘Shengeh’. The samples were collected from four locations in Iran (Gorgan, Sare-polzohab, Roudbar, and Taroum). The quality parameters included the peroxide value, chlorophyll, carotenoid, and composition of fatty acids.
The purity was also assessed using a UV spectrophotometric technique focusing on the absorbance at 232 nm (K232) and at 270 nm (K270). Based on the measured parameters; ‘Mari’ oil quality was higher than the ‘Shengeh’ because of the higher ratio of monounsaturated to polyunsaturated fatty acids, chlorophyll, and carotenoids.
However, the peroxidase value for ‘Mari’ was significantly lower than ‘Shengeh’. The oil from Sare-pole Zohab located in the Kermanshah region with an altitude of 545 m had a higher rank for unsaturated fatty acids especially oleic acid in comparison with other samples.
The cultivar and producing regions had a significant influence on the oleic acid content of the K232 and absorbance parameter.
To know differences in the related gene sequence, DNA was extracted from the collected samples.
Forward and reverse primers were designed for the SAD2 (stearoyl-ACP desaturase) gene using the conserved sequence of the gene in model plants. SAD2 gene was amplified and then sequenced for samples.
Nucleotide sequence analysis was indicated that ‘Shengeh’ from Gorgan and Sare-polzohab had the most similarity to each other.
However, ‘Mari’ collected from Gorgan (Golestan) revealed differences in both the sequence and level of oleic acid in comparison to the other cultivars.
The most homology within the SAD2 sequence was found from 651 to 737 bp.
The samples which owned significant differences in oleic acid level also indicated less homology in the 128 bp sequence of the SAD2 gene.

I International Conference and X National Horticultural Science Congress of Iran (IrHC2017)

S. Mahmoudi, M.M. Sharifani, A. Yamchi, M. Alizadeh

oleic acid, oil quality, stearoyl acyl desaturase, olive oil

https://doi.org/10.17660/ActaHortic.2021.1315.84