Studies on the molecular basis of flowering in longan (dimocarpus longan)

We attempt to identify the molecular basis of flower induction in Longan by expression patterns of genes that encode for proteins similar to Arabidopsis thaliana flowering genes. Potassium chlorate (KClO3) was applied as a soil drench at 150 g/tree to fully mature field grown trees in April 2008 at the Banpong Research Centre, Mae Jo University, Thailand. Samples of terminal buds and leaves were collected 12 times at 2 day intervals following KClO3 application for RNA extraction. Four degenerate primer pairs of the flowering locus T (FT) were designed by using highly conserved regions in eleven plant species, including Arabidopsis thaliana. Two pairs of the FT degenerate primers were successfully amplified in Longan by nested PCR and fragments were subsequently cloned and sequenced. BLAST searches with this sequence aligned with the Arabidopsis genome identified FT with an amino acid identity of 68% and homology of 68%. It was concluded that Longan homologue of FT was successfully isolated.