Inter- and intra-specific diversity of Cuban Pinguicula (Lentibulariaceae) based on morphometric analyses and its relation with geographical distribution Yoannis Domínguez a,b *, Saura R. da Silva c , Cristina M. Panfet Valdés d and Vitor F.O. de Miranda c a Universidade de Mogi das Cruzes, Mogi das Cruzes, Brazil; b Departamento de Biología y Sanidad Vegetal, Universidad Agraria de La Habana, Laboratorio de Botánica, San José de las Lajas, Cuba; c Departamento de Biologia Aplicada à Agropecuária, Faculdade de Ciências Agrárias e Veterinárias, UNESP – Univ Estadual Paulista, Laboratório de Sistemática Vegetal e Palinologia, Jaboticabal, Brazil; d Universidad de La Habana, Jardín Botánico Nacional de Cuba, La Habana, Cuba (Received 27 March 2013; accepted 5 September 2013) Background: Phenotypic variations have been observed in populations of west Cuban Pinguicula species. Such populations occur in patches under different ecological conditions associated with specialised habitats and separated by geographical and ecological barriers, which can lead to morphological differentiation. Aims: To analyse morphological diversity among species and populations of Cuban Pinguicula; and to test if morphological variability is associated with geographical distribution and distance between populations. Methods: We sampled a total of eight populations of P. albida, P. cubensis and P. filifolia and tested for morphometric differences among them by Principal Component Analysis (PCA) and analysis of variance (ANOVA) based on 31 quantitative traits. We also assessed the geographical isolation with respect to morphological distance. Results: The studied species showed high morphological variability at both species and population level. Reproductive characteristics appeared to be more promissory than vegetative ones in distinguishing geographical groups since they clearly defined populations; nevertheless a strong component of individual variation was observed. According to the distance analysis, such morphological variations were correlated with fragmented populations and isolation and allowed the differentiation of two morphotypes of P. albida and two of P. filifolia. Conclusions: We conclude that high phenotypic variation of the analysed species is related to geographical and ecological isolation which have led to the differentiation of morphotypes within species. Keywords: carnivorous plants; ecological islands; fragmented populations; isolation; habitat specificity; morphometry; morphotype; restricted distribution Introduction The carnivorous plant genus Pinguicula L. (Lentibulariaceae) comprises about 100 species (Rondoni et al. 2010), although recent studies have revealed several new taxa throughout its distribution range. Pinguicula is mostly distributed in the northern hemisphere and in tro- pical and subtropical America, and is associated with poorly structured, wet soils. The Central American– Caribbean region is known as its diversity centre due to the great number of species occurring in these areas (Casper and Stimper 2009). In Cuba, 13 Pinguicula species have been recognised, all of which are endemic and considered threatened according to International Union for Conservation of Nature (IUCN) categories and criteria (Berazaín et al. 2005). In general, insular biotas are more susceptible to extinction than mainland ones due to the demographic and environmental stochasticity associated with small population size, discontinuous distribution and genetic factors (Frankham 1997). In addition, endemic species are seriously compromised due to their limited ability to adapt to environmental changes (Traveset 2001) and to colonise new habitats. It is known that insular endemic species show lower genetic variation than populations of related species from the mainland (Frankham 1997), and with increasing isolation, the probability or frequency of immigration decreases (Pickett and Thompson 1978; Gotelli 1991). Most conservation areas in the Cuban archipelago are located in the western region of the country because of the great diversity of ecosystems and their high biodiversity (Borhidi 1996; Urquiola et al. 2010). Throughout the last decades, however, the original landscapes of western Cuba have been modified due to increasing agriculture, cattle ranches, mining and other anthropogenic activities which have led to the fragmentation and/or loss of original popu- lations. Three Pinguicula species are known in western Cuba: Pinguicula albida C.Wright ex Griseb., P. cubensis Urquiola & Casper and P. filifolia C.Wright ex Griseb. As for many rare endangered species, all three occur in small local populations in fragmented habitats associated with specific conditions within patches (Table 1); consequently, they have a restricted and disjunct distribution due to the loss or modification of original habitats (Figure 1). Environmental conditions are often likely to vary between geographically distant sites, whereas conditions between *Corresponding author. Email: yoannisd@gmail.com Plant Ecology & Diversity , 2013 http://dx.doi.org/10.1080/17550874.2013.842616 © 2013 Botanical Society of Scotland and Taylor & Francis Downloaded by [Yoannis Domínguez] at 18:07 18 December 2013