REPORT Morphological and physiological characterization of two new pineapple somaclones derived from in vitro culture Guillermo Pérez & Andrew Mbogholi & Fernando Sagarra & Carlos Aragón & Justo González & Miriam Isidrón & José Carlos Lorenzo Received: 2 June 2010 /Accepted: 4 January 2011 / Editor: D. T. Tomes # The Society for In Vitro Biology 2011 Abstract We previously reported a partial agricultural and amplified fragment length polymorphism (AFLP) characterization of two new pineapple somaclones (P3R5 and Dwarf) derived from in vitro culture of the donor cv. Red Spanish Pinar. Both somaclonal variants showed different AFLP banding patterns compared to the donor cultivar, although they were separated by less than 0.09 U of genetic distance. The present report shows data of various indicators of morphology and physiology of P3R5 and Dwarf D leaves. The stoma diameter, number of stomata per square millimiter, diameter of leaf vascular tissue, thickness of the leaf aquiferous parenchyma, and thickness of the leaf photosynthetic parenchyma were measured. The photosynthetic rate, the transpiration rate, the water use efficiency, the internal leaf CO 2 concentration, and the chlorophyll pigment contents were recorded as well. Between the somaclonal variant P3R5 and the donor genotype, statistically significant differ- ences were recorded in all indicators with the exception of the stoma diameter and the photosynthetic rate. Compar- ing the somaclonal variant Dwarf and the cv. Red Spanish Pinar (donor), statistically significant differences were also recorded in all parameters except in the stoma diameter and in the transpiration rate. This investigation was performed to demonstrate that small changes in the pineapple DNA may result in relevant phenotypic modifications. Keywords Ananas comosus (L.) Merr. . Phenotype variation . Leaf morphology . Physiology Introduction Pineapple belongs to the Bromeliaceae family and is one of the most economically important tropical fruits. The worldwide production in 2008 was 19.16 million tons (Food and Agriculture Organization of the United Nations (FAOSTAT) 2010). Because of this, several research groups are developing basic and applied studies to create new varieties with better agronomic performance. As classical pineapple breeding is extremely laborious and time consuming (Cabot and Lacoevilhe 1990), biotech- nology is an attractive tool for improving elite clones (Sripaoraya et al. 2001; Espinosa et al. 2002; Botella and Fairbairn 2005; Sripaoraya et al. 2006; Carlier et al. 2007; Yabor et al. 2009). Genetic variation is very important in crop improvement and forms the basis of development of new varieties. Somaclonal variation is a valuable tool in plant breeding wherein variation in tissue culture regenerated plants from somatic cells can be used in the development of crops with novel traits (Cardoza and Stewart 2004). Larkin and Scowcroft (1981) were the first researchers to demonstrate and coin the term somaclonal variation. Variations may pre- exist in the natural population of plants from field collection or genebank or it may develop de novo as a result of tissue culture conditions (Castillo et al. 2010). In recent years, a number of studies have measured, through molecular markers, the extent of somaclonal variation in plants (Aversano et al. 2009). Lack of polymorphisms associated with in vitro regeneration was reported in tomato (Smulders et al. 1995), Norway spruce G. Pérez (*) : A. Mbogholi : F. Sagarra : C. Aragón : J. González : M. Isidrón : J. C. Lorenzo Laboratory for Plant Breeding, Centro de Bioplantas, Universidad de Ciego de Ávila, Ciego de Ávila 69450, Cuba e-mail: pfa_guillermo@agronomia.unica.cu URL: www.bioplantas.cu In Vitro Cell.Dev.Biol.—Plant DOI 10.1007/s11627-011-9342-y