Adaptation patterns of sixteen alfalfa (Medicago sativa L.) cultivars across contrasting environments of Algeria and implications for the crop improvement

摘要

The additive main effects and multiplicative interaction analysis was applied to assess the genotype × environment interaction (GEI) effects and stability for 4year dry matter yield (DMY) of 16 alfalfa (Medicago sativa L) cultivars of diversified geographic origin grown in four Algerian environments given by the combination of two water managements (rainfed and irrigated) and two evaluation sites, viz the subhumid location of Alger and the semiarid, salinityaffected site of Hmadna The analysis of variance (ANOVA) revealed significant variation among cultivars and environments (P0001) The GEI was significant (P0001) and the environment main effect had greater influence than the genotype effect on longterm yield according to ANOVA Rainfed conditions had 416% and 485% lower yield than the irrigated ones in Alger and Hmadna, respectively Alfalfa cropping in the semiarid location caused lower DMY than in the subhumid one (– 380% under irrigated and –452% under rainfed conditions) and a slightly lower persistence over the 4year period Outstanding environmentspecific cultivar responses were observed, fully justifying the large GEI effects, although the Italian cultivar Sicilian ecotype had remarkable yield stability and good mean yield The American variety Ameristand 801S and the Moroccan landrace Erfoud 1 were the most salttolerant cultivars The evaluated germplasm, and particularly some exotic cultivars, could be used as parents to breed new varieties more adapted to drought and salinity in the Mediterranean basin.