Abstract
AbstrAct. We used a set of 48 near-isogenic lines derived from the intraspecific cross between an inodorus and conomon
type melon to perform QTL analyses of Brix (°Brix) and soluble sugar content in three locations in summer 2011
and 2012. A QTL was detected in NIL SC5-1 (ssc5.1) in the three locations which decreased °Brix by 25 % to 35 %,
and sucrose content by 71 % in one location compared to the PS control. To develop recombinant sub-NILs containing
smaller introgressions of SC, NIL SC5-1 was crossed with PS to generate an F2 population. A set of 48 SNPs was
developed covering the SC introgression of approximately 1.92 Mb contained within scaffolld00022 in order to refine
the positions of the smaller introgressions of recombinants. Seventeen segregating lines containing SC introgressions of
various sizes (between 20 Kb and 1.8 Mb) were identified. The F3 seedlings derived from the segregating F2 lines were
genotyped to identify those fixed for SC or PS alleles. The °Brix assessment was repeated on mature fruits in one location.
Means varied between 10.6 and 14.9 °Brix and the ssc5.1 QTL was detected in 5 lines that decreased °Brix from
12 % to 29 % compared to the PS control. The F4 seed was obtained and a larger experiment with more replications
will be performed in 3 locations in 2014 to confirm the effect of the QTL in the sub NILs.
