Genetic linkage map construction and location of QTLs for fruit-related traits in cucumber

A 173-point genetic linkage map of cucumber (Cucumis sativus L.), consisting of 116SRAPs, 33 RAPDs, 11 SSRs, 9 SCARs, 3 ISSRs, and 1 STS, was constructed using 130 F-2 progeny derived from a narrow cross between line S94 (Northern China open-field type) and line S06 (greenhouse European type). The seven linkage groups spanned 1016 cM with a mean marker interval of 5.9 cM. Using the F-2 population and its F-3 derived families, a total of 38 QTLs were detected on five linkage groups with an LOD threshold of 3.0 for nine fruit-related traits: fruit weight, length, and diameter, fruit flesh thickness, seed-cavity diameter, fruit-stalk length, fruit pedicel length, length/diameter and length/stalk ratio. Of the identified QTLs, fs/4.3 for fruit-stalk length explained the largest portion of phenotypic variation (r(2) = similar to 30%). Several QTLs were detected in the same linkage region in different generations and different seasons. Additionally, several QTLs for various fruit traits were mapped to the same or neighbouring marker intervals, suggesting they are possible character associations for controlling cucumber fruit development.