Polymorphism analysis in some Algerian Opuntia species using morphological and phenological UPOV descriptors

Boubakr Hadjkouider 1,2*, Ammar Boutekrabt 1, Bahia Lallouche 2, Salim Lamine 3,4, Néjia Zoghlami5 Botanical Sciences 95 (3): 391-400, 2017 DOI: 10.17129/botsci.887 Copyright: © 2017 Hadjkouider et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. All authors contributed equally during the preparation of this work. Department of Agricultural Sciences. Faculty of Nature and Life Sciences. Saad Dahlab University, Blida, Algeria. 2 Department of Agricultural Sciences, Faculty of Science, Mohamed Boudiaf University, M’sila, Algeria. 3 Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Ceredigion, UK. 4 Laboratory of Management and Valorization of Natural Resources and Quality Assurance. University of Bouira, Bouira, Algeria 5 Laboratory of Plant Molecular Physiology, Biotechnology Centre of Borj-Cédria, Hammam-lif, Tunisia. * Corresponding author: 1 Abstract Background: In the present study, we have investigated the morphological variation in a set of five Opuntia species from the Algerian steppes using 49 UPOV descriptors. Questions: Which of the 49 descriptors that can be used as powerful estimators of the phenotypic diversity within Opuntia species? How is the morphological diversity patterned in Algerian Opuntia? Species study/ Mathematical model: Opuntia ficus-indica, Opuntia amycleae, Opuntia streptacantha, Opuntia engelmannii, Opuntia robusta. Principal Components Analysis (PCA) and Hierarchical Cluster Analysis were used. Study site: Four counties were studied located in the Algerian steppes. The present research was carried out during 2014. Methods: 49 descriptors adopted by the International Union for the Protection of New Varieties of Plants (UPOV) were employed in the present research, where cladode, flower and fruit traits were used to determine the overall degree of polymorphism among 5 Opuntia species. Results: Principal Component Analysis and Hierarchical Cluster Analysis indicated a consistent differentiation between all studied species. The relative magnitude of the first two PCA eigenvectors showed that 8 descriptors out of 49 were identified as the most important descriptors for the classification of the species. The dendrogram performed on the calculated Euclidean distances between all species pairs allowed the identification of 3 groups, unlike the PCA that identified 4 groups. The species Opuntia ficus-indica and Opuntia amycleae were identified as very close morphologically. Conclusions: The present outcome represents a paramount step towards the fast selection of interesting species and for their best management and conservation. Key words: Opuntia, diversity, multivariate analyses, clustering, UPOV. Resumen Antecedentes: En el presente estudio, hemos investigado la variación morfológica en un conjunto de cinco especies de Opuntia de las estepas argelinas utilizando 49 descriptores UPOV. Preguntas: ¿Cuáles de los 49 descriptores que pueden ser utilizados como estimadores poderosos de la diversidad fenotípica dentro de las especies de Opuntia? ¿Cómo se modela la diversidad morfológica en el Opuntia Argelina? Especie en estudio/ Modelo matemático: Opuntia ficus-indica, Opuntia amycleae, Opuntia streptacantha, Opuntia engelmannii, Opuntia robusta. Análisis de Componentes Principales (PCA) y un Análisis de Agrupamiento Jerárquico fueron usados Sitio de estudio y fechas: Se estudiaron cuatro condados situados en la estepa argelina. La presente investigación se realizó durante el año 2014. Métodos: En la presente investigación se utilizaron 49 descriptores adoptados por la Unión Internacional para la Protección de las Obtenciones Vegetales (UPOV), en los que se utilizaron características de cladodio, flor y fruto para determinar el grado global de polimorfismo entre 5 especies de Opuntia. Resultados: Se aplicó un análisis multivariado, constituido por un análisis de componentes principales (PCA) y un análisis de agrupamiento jerárquico, cuyo resultado indicó una diferenciación consistente entre las especies estudiadas. Con base en la magnitud relativa de los dos primeros eigen-vectores del PCA se seleccionaron 8 de los 49 descriptores morfológicos como los más relevantes para la clasificación de las especies siendo los que más contribuyeron a la variación morfológica detectada. Dichos descriptores pertenecen a la lista de descriptores primarios establecida por la UPOV para la caracterización de Opuntia. El dendrograma obtenido aplicando el método de Ward (1963) para el cálculo de las distancias euclídeanas entre pares de poblaciones permitió identificar tres grupos distintos, mientras que el análisis PCA diferenció cuatro grupos. Por consiguiente, las especies Opuntia ficus-indica y Opuntia amycleae fueron identificadas como especies muy cercanas filogenéticamente. Conclusiones: Estos resultados representan un avance crucial para la selección e identificación rápida de poblaciones de interés y una mejora para las estrategias de gestión y conservación. Palabras clave: Opuntia, la diversidad, análisis multivariado, agrupación, UPOV. 391 Boubakr Hadjkouider et al. T he Cactaceae are dicotyledonous angiosperms, most plentiful in the arid and semi-arid regions between 35 N and 35 S composed of about 2,260 accepted species (Taylor 1997). Among these, the genus Opuntia L. Mill. has as many as 215 species. Opuntia has been exploited since the pre-Columbian times and is mainly present in North and South America, but has also been introduced into the Mediterranean basin, Middle-East, South Africa, India, Thailand and Australia. The species reached the Mediterranean basin during the 16th century (Barbera 1995). Nevertheless, only towards the end of the 20th century have large plantations been established, where only rough estimates of the worldwide plantation area (Zoghlami et al. 2007) are allowed due to the absence of updated statistical data from countries in which this species is cultivated. During the last decade, cacti (Opuntia ficus-indica) They have been used for almost 500 years as a fruit crop, a defensive hedge, and, more recently, as a fodder crop and as a standing buffer feed for drought periods; they can also play a key role in erosion control and land rehabilitation, particularly in arid and semi-arid zones, and as a shelter, refuge and feed resource for wildlife (Le Houérou 1996a). Generally, the characterization of Opuntia genus is incomplete due to few morphological characters taken into account to classify them into the genus (Rebman & Pinkava 2001); also, the inadequate descriptors have led to misclassification (Caruso et al. 2010, Majure et al. 2012), they usually lack botanical references and other data, which makes it difficult to properly document and register different varieties under the basis of a reliable c (...truncated)