Research advances and prospects of spinach breeding, genetics, and genomics

Abstract

Spinach (<i>Spinacia oleracea</i>) is a diploid (2n = 2x = 12), wind-pollinated crop, and highly heterozygous crop. The plants are mostly dioecious, although some monoecious plants exist. Spinach is an economically important cool-season leafy vegetable crop. Demand for spinach is increasing worldwide, particularly with its high nutritional contents. Spinach is a versatile crop eaten raw or cooked and used as salads or mixed with other cuisines. This review article provides an overview of origin and domestication, genetic diversity and population structure, genetic and genomic resources, major diseases threatening spinach production, breeding progress, and synthesizing how these resources can help spinach improvement. The rapid development of genomic and sequence resources of spinach has increased biological and genetics research and laid the foundation for adopting molecular breeding. Downy mildew is the most serious disease of spinach and the breeding programs focus on developing cultivars resistant to continually emerging new races of downy mildew pathogens. The use of genomic and molecular approaches offers promises in population improvement and hybrid development to address the production challenges of biotic and abiotic stresses and provide improved breeding materials and strategies against the rapidly changing pathogen races and climatic conditions.