QTL Analysis for Sugar Content Related Traits in Watermelon
CHENG Yao,LIU Shi,ZHU Zi-cheng,LUAN Fei-shi*
Horticulture College,Northeast Agricultural University,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops(Northeast region), Ministry of Agriculture,Harbin 150030,Heilongjiang,China
A recombinant inbred lines(RILs)of 125 F2S7 progenies were derived from the cross,a watermelon line‘ Huayuanmuben’ with high sugar content as female parent, and a watermelon line‘ LSW-177’ with low sugar content as male parent. A genetic linkage map was constructed by using cleavage amplified polymorphic sequence(CAPS) markers. The map contained 245 CAPS markers and grouped into 11 linkage groups,spanning a total length of 2 423.9 cM,with an average gap of 9.9 cM between each marker. A quantitative trait locus(QTL) analysis was conducted by using composite interval mapping method(CIM) to locate fruit sugar content locus. A total of 4 QTLs related to soluble solids content were identified,showing 14.80%,11.50%,32.10% and 8.60% phenotypic variances,respectively. 3 QTLs related to fruit fructose content were identified,showing 8.80%,20.50% and 9.50% phenotypic variances,respectively. One QTL related to fruit sucrose and 1 QTL related to glucose content were identified,showing 11.34% and 24.10% phenotypic variances,respectively.These 9 QTLs showed a positive additive effect for sugar content means cultivar‘ Huayuanmuben’ contributed the favorable alleles.