Genetic diversity and population structure o Jujube cultivars in the United States revealed by single nucleotide polymorphism markers

Authors: SAPKOTA, DIKSHYA - New Mexico State University; Zhang, Dapeng; Park, Sunchung - Sun; Meinhardt, Lyndel; YAO, SHENGRU - New Mexico State University

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/19/2024
Publication Date: 3/5/2024
Citation: Sapkota, D., Zhang, D., Park, S., Meinhardt, L.W., Yao, S. 2024. Genetic diversity and population structure o Jujube cultivars in the United States revealed by single nucleotide polymorphism markers. Journal of the American Society for Horticultural Science. 149(2):107-120. https://doi.org/10.21273/JASHS05370-23.
DOI: https://doi.org/10.21273/JASHS05370-23

Interpretive Summary: Jujube, also called Chinese date or Chinese jujube, is an economically important fruit tree with outstanding adaptability to a broad range of environmental and climate conditions. This fruit crop is indigenous to China but is becoming increasingly popular in the US. There are more than one hundred jujube cultivars in the United States and most of them were introduced from China. Accurate cultivar identification is essential for effective management of jujube germplasm. In the present study, we genotyped 159 jujube trees representing most of the commercial jujube cultivars in the United States using SNP markers. The resultant DNA fingerprints enabled the detection of a significant number of duplicate groups in these commercial cultivars. Following the SNP genotyping, morphological characterization was performed on fruit, stone, flower, and total soluble solids. Results of morphological characterization and SNP genotyping are highly compatible in most of the commercial cultivar groups. Nonetheless, morphological variations were observed in several duplicate groups assigned by SNP markers, indicating clonal mutations among these cultivars. The present result demonstrated that while SNP fingerprinting is a powerful tool for jujube cultivar identification, morphological characterization remains essential to complement SNP fingerprinting. The current findings provided useful information about the genetic identity and key morphological characteristics of commercial jujube cultivars in the United States. These results will be used by jujube researchers and growers to improve the accuracy and efficiency of germplasm management, nursery propagation and selection of superior cultivars for jujube production.

Technical Abstract: Jujube (Ziziphus jujuba Mill.), also called Chinese date or Chinese jujube, is an economically important fruit tree with outstanding adaptability to a broad range of environment and climate conditions. There are more than one hundred jujube cultivars in the United States and most of them were introduced from China. Accurate cultivar identification is essential for effective management of jujube germplasm. In the present study, we genotyped 159 jujube trees representing most of the commercial jujube cultivars in the United States. The genotyping used 192 SNP markers via Kompetitive Allele Specific PCR (KASP) technology. Multi-locus matching detected a significant number of synonymous groups in these commercial cultivars. Following the SNP genotyping, morphological characterization was performed on fruit, stone, flower, and total soluble solids. Results of morphological characterization and SNP genotyping are highly compatible in most of the commercial cultivar groups. Nonetheless, morphological variations were observed in several synonymous groups assigned by SNP genotyping, indicating clonal mutations among these cultivars. In addition, analysis of genetic diversity revealed new insights into the genetic relationship among cultivar groups. The present result demonstrated that while SNP fingerprinting is a powerful tool for jujube cultivar identification, morphological characterization remains essential to complement SNP fingerprinting. The current findings provided useful information about the genetic identity and morphological characteristics of commercial jujube cultivars in the United States. This information can be used for germplasm management, nursery propagation and the selection of superior genotypes by researchers and growers in the jujube industry.