Cloning and transcription analysis of an AGAMOUS- and SEEDSTICK ortholog in the orchid Dendrobium thyrsiflorum (Reichb. f.) Evolution of the Monocotyledonous PISTILLATA Lineage and its Utility as a Phylogenetic Marker Expression of PISTILLATA is not restricted to petals and stamens in the orchid Dendrobium thyrsiflorum (Reichb. f.) Identification and quantification of expression levels of three FRUITFULL-like MADS box genes from the orchid Dendrobium thyrsiflorum