Cloning and Sequence Analysis of Phytoene Synthase cDNA from Lycium barbarum Allelic Variations of Phytoene Synthase Genes Controlling Yellow Pigment Content in Durum Wheat (Triticum turgidum L.) Cloning and sequential analysis of phytoene synthase (PcPSY1)gene in Pogostmen cablin Isolation and Characterization of Watermelon Partial cDNA Ecoding Phytoene Synthase Gene Isolation and Expression of Phytoene Synthase Gene in Gardenia jasminoides