Anales del Jardín Botánico de Madrid ISSN: 0211-1322 [email protected] Consejo Superior de Investigaciones Científicas España González, Ana María; Vesprini, José Luis Anatomy and fruit development in Schinopsis balansae (Anacardiaceae) Anales del Jardín Botánico de Madrid, vol. 67, núm. 2, julio-diciembre, 2010, pp. 103-112 Consejo Superior de Investigaciones Científicas Madrid, España Disponible en: http://www.redalyc.org/articulo.oa?id=55617069004 Cómo citar el artículo Número completo Sistema de Información Científica Más información del artículo Red de Revistas Científicas de América Latina, el Caribe, España y Portugal Página de la revista en redalyc.org Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto Anales del Jardín Botánico de Madrid Vol. 67(2): 103-112 julio-diciembre 2010 ISSN: 0211-1322 doi: 10.3989/ajbm.2254 Anatomy and fruit development in Schinopsis balansae (Anacardiaceae) by Ana María González 1 & José Luis Vesprini 2 1 Instituto de Botánica del Nordeste, Corrientes, Argentina. [email protected] 2 Facultad de Ciencias Agrarias, UNR. CONICET, Rosario, Argentina. [email protected] Abstract Resumen González, A.M. & Vesprini, J.L. 2010. Anatomy and fruit develop- González, A.M. & Vesprini, J.L. 2010. Anatomía y desarrollo de los ment in Schinopsis balansae (Anacardiaceae). Anales Jard. Bot. frutos en Schinopsis balansae (Anacardiaceae). Anales Jard. Bot. Madrid 67(2): 103-112. Madrid 67(2): 103-112 (en inglés). Schinopsis balansae Engl. is a dioecious tree; reproduction is by Schinopsis balansae Engl. es un árbol dioico, cuya reproducción woody samaras containing a single seed. Fruit set is high, even se realiza a través de sámaras uniseminadas. La producción de in isolated trees, empty fruits are frequent and account for a frutos es muy alta y una gran proporción de los mismos son va- high proportion of the total fruit production. To describe the nos. Con la finalidad de describir la anatomía y ontogenia de los anatomy and the ontogeny of seeded and seedless fruits, flow- frutos, con y sin semillas, se trabajó con flores y frutos en distin- ers and fruits at different development stages from bagged and tos estados de desarrollo. Se utilizaron inflorescencias femeninas pollen exposed flowers were studied. The development and the expuestas y embolsadas. El pericarpo de frutos con semilla y par- anatomy of the pericarp in seeded and parthenocarpic fruits did tenocárpicos presenta el mismo desarrollo y anatomía: está not differ. It consisted in an exocarp formed sensu lato from the constituido por un exocarpo formado sensu lato a partir de la external epidermis of the ovary and some layers of the underly- epidermis externa del ovario y algunas capas del parénquima ing parenchyma. The mature mesocarp was constituted by a subyacente. El mesocarpo maduro está constituido por es- sclerified tissue and lysigenous channels. The fruit is of Anac- clerénquima y canales lisígenos. Por las características del endo- ardium type: the endocarp presented three sclerenchymatic and carpo, este fruto se clasifica como tipo Anacardium, presentan- a crystalliferous layer. The endocarp development was also sen- do tres estratos esclerenquimáticos y uno cristalífero. El desarro- su lato because it was formed from the epidermis and the hypo- llo del endocarpo también es sensu lato, ya que deriva de la epi- dermis of the carpel. This organization agrees with the only dermis e hipodermis del carpelo. Esta anatomía concuerda con species described in the genus: S. haenkeana Engl. Schinopsis la descrita para S. haenkeana Engl., única especie estudiada de balansae is able to produce parthenocarpic fruits in the absence este género. S. balansae desarrolla frutos partenocárpicos aun- of pollination. Empty fruits from free exposed flowers presented que no se produzca polinización. Los frutos vanos producidos embryos arrested at different stages, although total absence of por polinización libre tienen embriones en distintas etapas de an embryo was the most common condition. Parthenocarpy desarrollo, no obstante, la condición más común es la ausencia seems to be a plesiomorphic trait within the Anacardiaceae, but del mismo. La partenocarpia parece ser un carácter plesiomórfi- regardless of its origin, the maintenance of empty fruit produc- co en las Anacardiaceae, sin embargo la producción de frutos tion in a wind-dispersed samara is difficult to explain. Whether vanos de dispersión anemófila es difícil de explicar. Si la parte- parthenocarpy has an adaptive value, or is an evolutionary con- nocarpia tiene un valor de adaptación o es una restricción evo- straint remains unclear in Schinopsis. lutiva sigue siendo poco claro en S. balansae. Keywords: dioecy, dry fruits, fruit ontogeny, parthenocarpy, Palabras clave: dioecia, frutos secos, frutos vanos, partenocar- agamospermy, samaras, quebracho, empty fruits, pericarp. pia, pericarpio, quebracho, sámaras. Introduction called “quebrachales”. Although most species of the Schinopsis balansae Engl. is a dioecious tree that Ana cardiaceae family has drupaceous fruits, many grows in Argentina, Bolivia, Paraguay and Brazil, of them adapted to different dispersers, S. balansae and is the dominant species of Argentine forests fruits are woody samaras with a single oblong wing 104 A.M. González & J.L. Vesprini and an ovoid seminiferous portion containing a single The aim of the present research was: seed. 1) To describe the anatomy and ontogeny of the Due to timber logging its populations have suffered pericarp. a marked reduction, and part of the area formerly cov- 2) To determine if fruit development is unrelated to ered by the species has been devoted to farming. De- fertilization, and if so, to compare pericarp develop- spite the economic, ecological and social importance ment in both seeded and seedless fruits. of the species, a basic knowledge on its biology is still lacking. Schinopsis reproduces only by means of seeds Material and methods and so, to determine the factors constraining fertile fruit production, how the samara develops, and Pistillate and staminate individuals growing in nat- whether or not pollination is necessary, is of funda- ural populations located at “Las Gamas” station, near mental importance for developing strategies for the Vera, Santa Fe province, Argentina, were studied. conservation of this species. Material from cultivated specimens in Corrientes City, Wannan & Quinn (1990) studied the fruit of 29 Argentina, was also studied. Vouchers of the speci- mens are deposited in the Herbarium of Instituto de genera in the Anacardiaceae. They recognized two ba- Botánica del Nordeste (CTES), Argentina. sic types of endocarp: the Spondias-type, which is In the natural population, inflorescences at flower composed of a mass of irregularly oriented scle- bud stage were bagged with two bags: an internal renchyma and the Anacardium-type, characterized by plastic mesh -to keep the outer bag free from the flow- a lignified outer epidermis and discretely layered and ers- and an external wax paper bag to impede pollen includes palisade like sclereids. Shinopsis haenkeana flow. Bagging was carried out during two flowering Engl was the only species studied by Wannan & periods: 2004 and 2005. One group of flowers was left Quinn (loc. cit.) and has been described and classified in the bags until fruit dispersal, when we determined: as Anacardium-type. So far the anatomic structure of the number of abscised flowers, and undeveloped and the fruit in S. balansae remains unknown. mature fruits. Empty fruits are frequent and can account for al- Subsets of the flowers and fruits were collected at most half the total fruit production (Alzugaray, 2005). different developmental stages from free exposed Fruit set is striking since before maturity the red sama- flowers, bagged flowers, and also from unbagged ras are easily observed on pistillate individuals. No- flowers of very isolated individuals from both popula- tably, isolated trees can also yield huge amounts of tions. This material was fixed in FAA (5% formalin, fruit as well as plants growing in dense populations, 5% acetic acid, and 90% ethyl alcohol), dehydrated and these observations led us to the hypotheses that in Johansen’s tert-butyl alcohol series and embedded fruit development may be independent of pollination, in paraffin (Johansen, 1940). Transverse (TS) and lon- and/or that embryo abortion does not prevent fruit gitudinal (LS) sections, 10-12 µm, were stained with a formation. safranin-Astra blue combination (Luque & al., 1986). Atypical fruit production is frequent in the Anacar- Histochemical tests included the FeSO4 (Ruzin, diaceae: there are cases of parthenocarpy (development 1999) and IKI-H2SO4 methods for tannins (Jensen, of fruit without fertilization) and fruit development fol- 1962), and phloroglucinol for cellulose/lignin. lowing embryo abortion. For instance, Grundwag & To check bagging efficiency and to detect pollen Fahn (1969) observed post-fertilization embryo abor- grain presence or germination, some bagged and free tion in Pistacia vera L., and Shuraki & Sedgley (1994) exposed flowers were fixed in FAA, stained with Ani- found that in P. vera funicle degeneration was the most line blue (Martin, 1949) and were observed using fluo- common cause to empty seeds. More recently, Polito rescence microscopy. The observations, drawings and (1999) found that vascular transport to ovules is photomicrographs were made with a Leica DM LB2 blocked at the placenta or in the funicle