Highre-solution linkage map and chromosome-scale genome assembly for cassava (Manihot esculenta Crantz) from 10 populations

Cassava (Manihot esculenta Crantz) is a major staple crop in Africa, Asia, and South America,
and its starchy roots provide nourishment for 800 million people worldwide. Although native to South
America, cassava was brought to Africa 400–500 years ago and is now widely cultivated across sub-Saharan
Africa, but it is subject to biotic and abiotic stresses. To assist in the rapid identification of markers for
pathogen resistance and crop traits, and to accelerate breeding programs, we generated a framework map
for M. esculenta Crantz from reduced representation sequencing [genotyping-by-sequencing (GBS)]. The
composite 2412-cM map integrates 10 biparental maps (comprising 3480 meioses) and organizes 22,403
genetic markers on 18 chromosomes, in agreement with the observed karyotype. We used the map to
anchor 71.9% of the draft genome assembly and 90.7% of the predicted protein-coding genes. The
chromosome-anchored genome sequence will be useful for breeding improvement by assisting in the rapid
identification of markers linked to important traits, and in providing a framework for genomic selectionenhanced
breeding of this important crop.