Accurate cultivar authentication of fresh and dry jujube fruits using DNA fingerprints based on a nanofluidic SNP genotyping system

Authors: SONG, LIHUA - Ningxia University; Meinhardt, Lyndel; LI, ZHANWEN - Ningxia University; WAN, ZHONGWU - Ningxia University; Zhang, Dapeng

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/27/2022
Publication Date: 8/30/2022
Citation: Song, L., Meinhardt, L.W., Li, Z., Wan, Z., Zhang, D. 2022. Accurate cultivar authentication of fresh and dry jujube fruits using DNA fingerprints based on a nanofluidic SNP genotyping system. Journal of Agricultural and Food Chemistry. 8(9):792. https://doi.org/10.3390/horticulturae8090792.
DOI: https://doi.org/10.3390/horticulturae8090792

Interpretive Summary: Jujube (Ziziphus jujuba Mill.) is an economically important fruit tree with outstanding adaptability to marginal lands and a broad range of climate conditions. This fruit crop is indigenous to China and has become increasingly popular in the US. One problem with the jujube market is the lack of a reliable method for cultivar authentication. The accurate determination of the genetic identity of a single jujube fruit is essential for ensuring cultivar traceability and botanical origin. Single nucleotide polymorphic (SNP) genotyping was applied to test the efficacy of genotyping DNA samples extracted from fruit pulp of different jujube cultivars, including both fresh and dried fruits. Based on the marker profiles, the genetic identity of each fruit was unambiguously identified with high accuracy and repeatability. The method is rapid, has a high throughput, robust and cost-effective, thus showing high potential for practical application in the jujube industry. These findings will be used by jujube researchers and the jujube industry for quality control in the value chain.

Technical Abstract: The Chinese Jujube (jujube, red date, Chinese date) is an economically important fruit tree with outstanding adaptability to marginal lands and a broad range of climate conditions. Chinese jujube fruits can be consumed as table use fresh date and processed dry date (or “red date”), the latter is consumed as snacks or as food remedies. One problem with the fresh and dry date market is adulteration of premium cultivars. Accurate determination of genetic identity of single jujube fruit is essential for ensuring cultivar traceability and authentication. The approach of multi-locus SNP barcoding offers an effective solution for cultivar authentication of jujube fruits. Using a nanofluidic array to identify variant SNP sequences, we tested the efficacy of this method using DNA extracted from fruit pulp of 10 jujube cultivars, including both fresh and dried fruits. Based on the profiles of SNP markers, the genetic identity of each fruit was unambiguously identified by multilocus matching and ordination analysis. Results for repeated samples of multiple fruits from the same products (using three independent DNA extractions) showed high level of concordance, demonstrating that the SNP based genotyping system is a reliable platform for generating DNA fingerprints for jujube fruits with high accuracy. The method can handle a large number of samples in a short period of time. It is robust and cost-effective, thus showing high potential for practical application in the value chain of the fresh and dry date industry.