Characterizing Palestinian snake melon (Cucumis melo var. flexuosus) germplasm diversity and structure using SNP and DArTseq markers.

BACKGROUND: Crop landraces embody a source of beneficial genes potentially providing endurance to environmental stress and other agronomic qualities including yield. Our study included 88 snake melon accessions (Cucumis melo var. flexuosus) collected from 9 districts in the Palestinian West-Bank. These accessions represent four landraces of Palestinian snake melon: Green, and White Baladi, and Green, and White Sahouri.

RESULTS: This is the first report on successful application of genotyping by sequencing in snake melon. Nine thousand seven hundred fifty single-nucleotide polymorphism (SNP) and 7400 DArTseq genetic markers were employed to evaluate genetic biodiversity and population structure of Palestinian snake melon germplasm collection. Clustering based on neighbor-joining-analysis, principle coordinate and Bayesian model implemented in Structure showed that patterns of genetic diversity of snake melon landraces depends on their geographical source and unraveled the presence of two major local landraces (Sahouri, and Baladi) with accessions from each group clustering together. A significant correlation was observed between both types of markers in Mantel correlation test. A significant association between genetic and geographic matrices (P < 0.0001) was also detected. AMOVA indicated that majority of variation (90%) was due to the difference within accessions.

CONCLUSION: The Palestinian landraces seem to have unique genes that may allow the enhancement of the global snake melon gene pool and developments of the plant production worldwide. Our subsequent objective is to detect genotypes with promising qualities and to conduct association mapping studies concentrating on Fusarium-wilt resistance, yield, and environmental stresses.