This study evaluated whether the herb Ruellia nudiflora is locally adapted to a specialist insect seed predator (SP) and insect folivores, and if plant local adaptation (LA) to the former is more likely. A reciprocal transplant experiment was conducted using three sites in Yucatan (Mexico) (n = 864 plants). A third of the plants of each origin were placed at each site, and we recorded the following during a 9‐month period: fruit number, leaf damage, and fruits attacked by SP. Results indicated lack of plant LA for all the variables measured. Instead, seed predation was c. 100% greater for native plants at one study site, suggesting insect LA or plant maladaptation; folivory was homogeneous across sites/origins. Based on these results, we discuss differences in the potential each herbivore guild has to promote plant LA, as well as divergent evolutionary outcomes of plant–herbivore interactions across sites.

Different environmental factors can have contrasting effects on the extent of plant local adaptation (LA). Here we evaluate the influence of folivory and soil type on LA in Ruellia nudiflora by performing reciprocal transplants at two sites in Yucatan (Mexico) while controlling for soil source and folivory level. Soil samples were collected at each site and half of the plants of each source at each site were grown with one soil source and half with the other. After transplanting, we reduced folivory by using an insecticide applied to half of the plants of each population source grown on each soil at each site. This resulted in a fully-crossed design with site, population source, soil source and folivory as main effects. We evaluated LA by means of a significant site 9 origin interaction showing a home-site advantage of native plants. Additionally, to test for an effect of soil source and folivores on LA, we estimated the three-way interactions of site 9 origin 9 soil source and site 9 origin 9 folivory. We recorded fruit number and survival throughout an 8-month period. For survival, we found evidence of home-site advantage at one site, while for fecundity we found no evidence of LA and at one site even observed evidence of lower fecundity for local relative to foreign plants. Importantly, folivory had no influence on the degree of home-site advantage for either response variable, while soil source influenced the degree of home-site advantage in fecundity at one site (suggesting some degree of specialization to soil characteristics in R. nudiflora). Our results emphasize the need for simultaneously evaluating multiple factors of influence in tests of LA.

Revista Mexicana de Biodiversidad 86 (2015) 508-520 Evolution Genetic diversity, outcrossing rate, and demographic history along a climatic gradient in the ruderal plant Ruellia nudiflora (Acanthaceae)Diversidad genética, tasa de entrecruzamiento e historia demográfica a lo largo de un gradiente climático en la planta ruderal Ruellia nudiflora (Acanthaceae) AbstractRuellia nudiflora has shown a high potential to easily invade disturbed areas. Outcrossing rate and genetic structure and diversity in this species were examined along a climatic gradient in the Yucatán Peninsula (Mexico) in order to understand the effects of environmental heterogeneityisolation by environment (IBE) -as well as correlation in herkogamy on genetic structure, diversity, and demographic history in this species. Nine populations were sampled along a temperature-precipitation gradient with marked differences in vegetation, measuring the degree of herkogamy in each sampled plant. To evaluate genetic diversity and structure, amplified fragment length polymorphism (AFLP) markers from 76 plants in these populations were used, while the outcrossing rate was evaluated in 22 genetic families from six populations. All populations had high levels of within-population genetic diversity and high outcrossing rates. Virtually all populations were also undergoing demographic and spatial expansion. The partial Mantel test found a positive correlation between geographic and genetic distance, but none between mean temperature, precipitation, and herkogamy with genetic distance. In this context, R. nudiflora shows incipient evidence of genetic differentiation on a small geographical scale (isolation by distance, IBD) but not along the environmental gradient (IBE). Results suggest that under conditions of constant disturbance, R. nudiflora is able to continuously colonize new areas. All Rights Reserved ResumenRuellia nudiflora ha mostrado un alto potencial para invadir fácilmente áreas perturbadas. Con la finalidad de comprender los efectos de la heterogeneidad ambiental (aislamiento por el ambiente, IBE) y de la correlación en la hercogamia, sobre la diversidad, estructura genética e historia demográfica de esta especie, se examinaron la tasa de entrecruzamiento, la estructura y diversidad genética a lo largo de un gradiente climático en la península de Yucatán (México). Se muestreó un total de 9 poblaciones a lo largo de un gradiente de temperatura-precipitación con marcadas diferencias en la vegetación, en donde además se midió el grado de hercogamia en cada planta. Para evaluar la diversidad y estructura genética, se usaron AFLP's en 76 plantas de estas poblaciones, mientras que la tasa de entrecruzamiento se evaluó en 22 familias genéticas de * Corresponding author.

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