|QU, SHUPING - University Of Wisconsin|
|PAN, YUPENG - University Of Wisconsin|
Submitted to: Cucurbitaceae Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/1/2014
Publication Date: 10/14/2014
Citation: Qu, S., Pan, Y., Weng, Y. 2014. QTL mapping of flowering time and fruit shape in Xishuangbana cucumber WI767 (Cucumis sativus L. var. xishuangbannanesis Qi et Yuan). Cucurbitaceae Proceedings. p. 13.
Technical Abstract: The Xishuangbanna cucumber (XIS) is a semi-wild landrace growing in the tropical southwest China, which has some unique traits that are useful for cucumber breeding. One such accession is WI7167 that exhibits dark green leaves, short hypocotyl, round fruit shape, orange flesh color in mature fruits, but short-day length requirement for flowering. The genetic basis of these traits in the XIS cucumber is largely unknown. In this study, we developed a mapping population with 138 F2:3 families that was derived from a cross between WI7167 (XIS cucumber, late flowering, round fruit shape) and WI7200 (cultivated cucumber, early flowering, short columnar fruit). A genetic map was developed with 225 SSR loci covering 775 cM in seven linkage groups. Phenotypic data on flowering time, the length and diameter of mature fruits were collected from 136 F2 and F2-derived F3 families in both greenhouse and field trials. QTL analysis with composite interval mapping in R/qtl identified two major effect QTLs for female flowering time, one QTL for male flowering time, four QTLs for fruit length, and three QTLs for fruit diameter. These QTLs explained 10.1-65.3% of observed phenotypic variations. The major effect QTL fft6.1 for female flowering time and mft6.1 for male flowering time were co-localized in cucumber chromosome 6. Results from this study were discussed in the context of domestication and diversification selection in the origin of the XIS cucumber.