SNP Discovery and Genetic Diversity in Spinach.

Spinach (Spinacia oleracea L., 2n=2x=12) is an economically important vegetable crop worldwide and one of the healthiest vegetables due to its high concentrations of nutrients and health-promoting compounds. The objective of this research is to discover single nucleotide polymorphism (SNP) using a genotyping by sequencing (GBS) platform and conduct genetic diversity analysis of world-wide spinach germplasm using SNP markers. A total of 413 spinach genotypes including 323 USDA-GRIN germplasm originally collected from 33 countries were used in this study. Around half million SNPs were discovered from the 413 spinach genotypes using GBS by de novo assembly. But only 380 SNPs were used for genetic diversity analysis due missing data. The genetic diversity analysis indicated that there was a geography (country) factor during spinach variety development and spinach production. The spinach germplasm from China, India, Iran, Japan, and Nepal were grouped together; the most Europe spinach lines belong to same group but Turkey spinach has own two groups; most of US spinach lines had one large group but the spinach lines developed from University of Arkansas were very closer each other and were grouped together differential from other US spinach lines. This research will provide SNP markers for molecular breeding and genetic diversity information for selecting parents in spinach breeding program.