Resumen de Variabilité phénotypique de la phénologie végétative et de la biomasse d'une espèce d'intérêt écologique et économique au Maroc: Atriplex halimus L.
Abdelmajid Haddioui, Mohamed Mahmoud Ould Mohamed Lamine, Lalla Hasna Zinelabidine, Said Bouda
- English
The halophyte plant, Atriplex halimus L., is of a great ecological and economical interest by its adaptation to the climatic and pedological conditions of the arid and semi-arid Mediterranean regions. This species, particularly adapted to arid and salt-affected areas, is used as a food for livestock forage, a wood source and a plant barrier against desert invasion (McKell 1989). In Morocco, A. halimus is widely distributed as a wild species. The description and the conservation of A. halimus genetic resources seem particularly important for the rehabilitation and disturbed areas by salt and low rainfall. Early study analysing the isoenzyme polymorphism, showed high genetic diversity in Moroccan populations of A. halimus(Haddioui & Baaziz 2001; Abbad et al. 2004a). In this study, the plant life history traits diversity of the same populations as studied by Haddioui & Baaziz (2001) was assessed using eleven morphological and phenological parameters. The morphological traits related with the ramification, leaves and fresh and dried mass production, which contributed mainly in the forage value of each plant were studied. The analysis of variance (ANOVA) has exhibited significant differences between populations for most of the morphological characters. Principal component analysis (PCA) highlighted two groups of population according to their geographical origin. The first group is composed by the littoral populations which are characterized by an increased vigour and high levels of forage production. All the remaining continental populations characterized by a weak vegetative development and low levels of forage production are clustered in the second group. This study showed a significant phenotypic heterogeneity between the nine studied populations. This variability is all the more significant as the populations are located in different climates.
- français
Dans une perspective de caractérisation des ressources naturelles d'Atriplex halimus L. au Maroc, la diversité phénotypique de neuf populations a été évaluée à l'aide de onze caracteres morphométriques. Les paramètres phénologiques, l'aspect morphologique des rameaux et des feuilles et la production des matières fraîche et sèche d'A. halimus ont été étudiés, en raison de leur contribution à la valeur fourragère. Des différences significatives des paramètres phénologiques, de taille et de production des matières fraîche et sèche ont été observées entre populations. Deux groupes de populations ont été distingués par ACP. Le premier groupe est constitué des populations qui proviennent de stations littorales, caractérisées par des plantes plus vigoureuses ayant une biomasse fraîche et sèche élevée. Le second groupe est constitué de populations continentales caractérisées par des plantes moins vigoureuses ayant une biomasse fraîche et sèche faible.
