Transgressive variation in quantitative traits is observed when the descendents of a sexual cross segregate with a range of phenotypes extending beyond that of their parents. Coupled with selection, the phenomenon of transgressive variation drives much of the continued progress achieved through plant breeding. In a previous study 11 QTLs affecting flowering time were identified in an advanced backcross quantitative trait locus (AB-QTL) study with the wild accession (IRGC 105491) as the donor parent and the tropical japonica cultivar Jefferson as the elite recurrent parent (Thomson et al. 2003). One of these transgressive loci, dth1.1, has been consistently detected in several studies using interspecific crosses (Xiao et al. 1998, Thomson et al. 2003; Cai and Morishima 2002; Septiningsih et al., 2003) but dth1.1 was not detected in studies using intraspecific crosses (Li et al. 1995; Yamamoto et al. 1998). Within the contiguous sequence across the dth1.1 region, six flowering time candidate genes were identified. Five candidate genes for dth1.1 had similarity with the protein sequences of Arabidopsis flowering time genes Gigantea (GI), Flowering Locus T (FT) [FTL and FT-L8], and Embryonic Flower 1 (EMF1). Finally, a candidate gene with similarity to PNZIP, a light regulated leucine (Leu) zipper gene from the Pharbitis nil was identified. The objective of this study is to use segregating NIL families to select lines with individual candidate gene locus as potentially underling the early flowering phenotype and test the hypothesis of multiple interacting loci participating in the early flowering associated within dth1.1