ARS | Publication request: A tale of two orchids: comparative reproductive development in Vanilla and Phalaenopsis

Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 8, 2009
Publication Date: July 18, 2009
Citation: O’Neill, S., W.-T. Yang, D. Gonsalves, and T. Matsumoto. A tale of two orchids: comparativereproductive development in Vanilla and Phalaenopsis. Plant Biology 2009. Honolulu, HI. P56035 pg. 369.

Technical Abstract: The orchid family of flowering plants (Orchidaceae) represents the largest, most diverse, and most successful family of flowering plants in the world yet they are one of the most understudied groups from a molecular and genomic perspective. To further the long-term goal of developing enabling genomic resources for key phylogenetic taxa within the Orchidaceae, we initiated fundamental and foundational studies of flower and fruit development in two phylogenetically distant orchid groups, the species Vanilla planifolia Jackson (Vanilloideae) and Phalaenopsis cv. V-3 (Epidendroideae), both economically important crop plants for agriculture and floriculture, respectively. Vanilla planifolia is an emerging tropical fruit crop for Hawaiian agriculture. Surprisingly, although Vanilla planifolia produces an agricultural fruit crop of major economic importance as a spice crop and is of critical importance to the basic subsistence income of many food-deficient, developing nations on Earth, there have been no recent studies of reproductive development. Nor has there been a contemporary anatomical and morphological investigation of flower development in the moth orchid, Phalaenopsis V-3, which is one of the most elite and valuable cultivars of ornamental orchids. In this study, we report our strategy for the development of genomic resources for Vanilla planifolia using Next Generation Sequencing technologies to characterize this relatively large and uncharacterized orchid genome. In addition, we present a comparative developmental study of gynostemium (fused female and male reproductive organs) development in Vanilla and Phalaenopsis, with a focus on the specific formation of the stigma and rostellum, both key floral modifications important for the initial pollen-signaling response, successful pollination and later fertilization, and for post-pollination development of the ovary, ovule, and fruit. This study provides crucial groundwork for applying genomic resources to understanding the evolution of orchid flower development in phylogenetically distant groups (primitive versus advanced). It will facilitate comparative studies among the Orchidaceae, as well as further ongoing international collaborative efforts for orchid crop improvement through genomic approaches.