Morphological and phenological variability within seven oasis populations of perennial alfalfa (Medicago sativa L.) in hyper-arid zone of southern Algeria

Abstract

In Algerian Saharian oases, the surfaces reserved for local populations of perennial alfalfa (Medicago sativa L.) have declined significantly in favor of other introduced cultivars. Their preservation has become more than necessary. In this perspective, a study conducted over two successive campaigns, in an hyper-arid area of Algeria (Adrar region), focused on the expression of twenty seven (27) morphological and phenological characteristics related to plants, pods and seeds within seven (07) local populations of different provenances: El-Menea (Ghardaïa), Tamentit (Adrar), Timimoun (Timimoun), El Guerrara (Ghardaïa), Aoulef (Adrar), In Ghar (In Salah) and Temacine (Touggourt). The ecological factors (rainfall, temperature, altitude) of the alfalfa provenance environments were also considered. The trial was carried out in a randomized complete block design with four (04) replications. The results indicate the existence of a great morphological variability between the populations for traits related to flowering and pods. The study revealed very strong correlations, particularly between the number of pods per plant (NPPl), the number of seeds per plant (NSPl) and the number of flowers per plant (NFPl) during the two successive years. The rainfall and the temperature (provenance environmental factors) acted on almost the totality of the studied characteristics, whereas the effect of the altitude seems to be of less importance. The three factors (respectively, temperature, rainfall and altitude) would have an influence on the precocity of the populations Aoulef, Inghar, Tamentit and El menea which showed a better performance for seed number, in spite of the very difficult climatic conditions characterizing this region of the country.