| Abstract Detail
Economic Botany: Applied Plant Biology Lubinsky, Pesach [1], Kim, Seung-Chul [2]. Origins, variation and domestication of vanilla: the case of Vanilla tahitensis J.W. Moore. VANILLA Swartz [Orchidaceae] is a pan-tropical genus of more than 100 species of hemi-epiphytic and saprophytic herbs. While the source of over 95% of natural vanilla is the cured fruit of Vanilla planifolia G. Jacks. in Andrews, a rare, Mexico/Central America endemic, an important niche market also exists for V. tahitensis, coveted for its thicker, more oil-rich fruits and distinct flavor notes. Having never been found in the wild, V. tahitensis is most similar in general aspect to neotropical Vanilla, and unique in at least one respect: it is the only polyploid reported in the genus. On the basis of morphological characteristics, it has been hypothesized to be a hybrid of either (1) recent provenance between V. planifolia and Vanilla pompona Schiede or (2) a F1 hybrid between V. planifolia and Vanilla odorata Presl. All three species are occasionally sympatric in tropical America. In order to test the hybrid origin(s) of V. tahitensis, sequence data from the ITS region of nrDNA and psbA-trnH non-coding region of cpDNA were generated to discern patterns of parentage, kinship, additivity, and overall phylogenetic signal. The results of the analysis from both trees indicate that V. pompona is distantly related to V. tahitensis. Non-congruence of the ITS and psbA-trnH topologies suggests genetic contributions from different species, with V. planifolia acting as the maternal donor. Analysis of ITS sequence data demonstrates a closer relationship of V. tahitensis to V. odorata, the latter highly divergent from V. planifolia in both the nrDNA and cpDNA trees. Low levels of observed additivity between putative parental species in ITS sequences contradict the suspected F1 hybrid status of V. tahitensis. Preliminary results of an AFLP survey looking for genome-wide patterns of additivity, the mixed ploidy levels observed in V. tahitensis, and historical geography of vanilla domestication will be discussed.
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1 - University of California Riverside, Department of Botany & Plant Sciences, Plant Resources Informatics Laboratory, Riverside, California, 92521-0124, USA
2 - University of California Riverside, Department of Botany & Plant Sciences, Riverside, California, 92521-0124, USA
Keywords:
Vanilla
domestication
neotropics
hybridization
Tahiti
polyploidy.
Presentation Type: Oral Paper:Papers for Topics
Session: 47-2
Location: 304/Bell Memorial Union
Date: Tuesday, August 1st, 2006
Time: 11:15 AM
Abstract ID:930 |
