Genomic Insights into the Cultivated Common Buckwheat: A Comprehensive Review on Genetic Diversity, Population Structure, and Marker Technologies

Abstract

Common buckwheat (Fagopyrum esculentum), a pseudo-cereal crop initially grown in Southern China, belongs to the Polygonaceae family. It has been cultivated extensively in Asia, America, and Europe, exhibiting traits like out-crossing and self-incompatibility. This review aims to consolidate studies on buckwheat's genetic diversity and population structure, utilizing a range of morphological and genetic traits for analysis. Genotyping is pivotal for pinpointing and assessing genes that offer agronomic benefits, and for comprehending population structures and allele frequency variations. Linkage models were first established in the 1980s using allozyme and morphological markers. Common buckwheat displays variations in its morphological traits, potentially attributable to its out-crossing behavior, also referred to as self-incompatibility. Allozyme markers were widely employed in population genetic research until the early 2000s. Conversely, RAPD analysis utilizes short 11 bp DNA fragments, amplified by PCR using RAPD primers at low annealing temperatures to facilitate DNA binding. The evolution of PCR technology spurred the development of diverse DNA marker schemes for linkage mapping in the 2000s. Nonetheless, these PCR-based markers failed to cover the entire genome, posing challenges for buckwheat genetic analysis. The emergence of next-generation sequencing has enabled genome-wide assessments across various species, buckwheat included. Recently, approximately 8,885 markers, representing 757 loci, were mapped to eight linkage groups in buckwheat, proving effective for genomic selection aimed at enhancing yield.