Vanilla planifolia Andrews (Orchidaceae): Labellum Variation and Potential Distribution in Hidalgo, Mexico

Abstract

Vanilla planifolia is a species of commercial importance. However, vanilla presents gene erosion problems due to its clonal reproduction. In the Huasteca of Hidalgo, there is no information on vanilla populations. Therefore, the objectives of this study were to identify the current populations and the potential distribution of, and the morphological variation in, the labellum of V. planifolia in the Huasteca of Hidalgo. Twenty-two accessions were located and selected. Based on 21 environmental variables, the niche modeling of the potential distribution was carried out with the MaxEnt program; with the Jackknife test being used to identify the variables that contributed to the model. Flowers from 22 accessions were collected and the labellum of each flower was dissected. Subsequently, 64 morphological variables were obtained and various multivariate analyses were performed. The results showed three regions, defined by the highest to the lowest probability that V. planifolia was distributed. The precipitation of the driest month, altitude, and vegetation cover delimited the distribution. Five different morphotypes were distinguished, and the main differences were associated with the middle part of the labellum as well as the entrance of pollinators to the flower; therefore, the characterization of the labellum showed an infraspecific variation in V. planifolia in populations of the Huasteca of Hidalgo.

Vanilla pompona Schiede (Vanilloideae-Orchidaceae): Morphological Variation of the Labellum in the Mexican Localities of Veracruz, Puebla, Jalisco and Oaxaca

“…Thus, in the V. pompona collections evaluated in our study, the middle and apical regions and the length of the labellum explain the variation. According to the studies conducted on variation of the labellum of the genus Vanilla [21][22][23][24], the variables used are suitable since, despite differences in the measures, shapes and size of the labellum in V. pompona and V. planifolia, these traits allow for the analysis of infraspecific variation and the variation between species.…”

“…Another cause of variation in the V. pompona labellum could be the environment, caused by the geographic location different from the collection sites. In Vanilla, the environment where the plants are found plays a highly important role in terms of availability of resources such as water, carbon and nutrients, and only the apical region of the labellum can be modified by the availability of these resources [24].…”

“…Infraspecific variation has also been evaluated by characterizing the labellum shape of species such as V. planifolia [21] and V. pompona [22]. In the Mesoamerican region, V. planifolia variation is identified by four morphotypes in Oaxaca [23], four morphotypes in the San Luis Potosí Huastec region, Mexico [21], and five morphotypes in the Hidalgo Huastec region, Mexico [24]. For V. pompona, floral morphological variation of the labellum is still being studied; to date, there is only one study that reports four morphotypes in collections from localities in Oaxaca.…”

“…The evaluation includes the morphological variation of Pseudolaelia vellozicola Hoehne populations [38] and populations of Pseudorchis straminea Fernald and P. albida Á.Love and D.Love [39]. In addition to studies on morphological variation in species of the Vanilla genus [21][22][23][24], studies of the labellum variation can be related with biotic factors (pollinators) and abiotic factors (environment). In orchids, biotic and abiotic factors, such as temperature and light, have been reported to influence the flowering period [40,41].…”

Frequency and behavior of Melipona stingless bees and orchid bees (Hymenoptera: Apidae) in relation to floral characteristics of vanilla in the Yucatán region of Mexico

“…The pre-Columbian people of north-central Veracruz, Mexico, are believed to be the earliest to cultivate vanilla; however, the oldest reports of vanilla refer to its use as spice for cacao-beverage by the Maya [ 8 ]. Today, production of vanilla in Mexico is concentrated around the eastern tropical regions, encompassing the states of San Luis Potosí, Hidalgo, Puebla and Veracruz [ 2 , 9 ]. In the South of Mexico, Chiapas and the Yucatán Peninsula are also home to vanilla cultivars, although cultivated at a lesser extent [ 10 ].…”