Extensive livestock is a basic socio‐economic feature of the Mediterranean region whose environmental and economic sustainability depends on the ability of forage resources to withstand climatically stressful conditions. Perennial forages such as tall fescue can be a valuable alternative to annuals, if they can survive across successive summer droughts. Three‐year dry matter yield and plant survival of five cultivars of Mediterranean‐type tall fescue were evaluated in six sites of Algeria, France, Italy, Morocco and Portugal, with the following objectives: (i) modelling adaptive responses and targeting cultivars as a function of environmental factors associated with genotype × location interaction; and (ii) defining plant ideotypes, adaptation strategies and opportunities for international co‐operation for regional breeding programmes. Site mean yield and winter temperatures were positively correlated, whereas sward persistence was positively correlated to lower site heat and drought stress. Cultivar adaptation was adequately modelled by factorial regression as a function of site spring–summer (April–September) drought stress (long‐term potential evapotranspiration minus actual water available) for yield, and annual drought stress for final persistence. Specific‐adaptation responses to high‐ or low‐stress environments emerged which were consistent with drought‐stress levels of cultivar selection environments. However, the wide‐adaptation response of cultivar Flecha suggested that breeding for wide adaptation can be feasible.

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A B S T R A C TM. minima (L.) Bart. is a pasture legume native to the Mediterranean Basin and is present throughout the Algerian territory. The work reported in this study was conducted in the aim to evaluate the diversity of pheno-morphological and agronomic traits in some local populations of Population from Oued Touil region was the earliest and has presented the best vegetative development in winter and in spring. On the other hand, population from Charef presented the best pod and grain yields. The PCA based on morphological and agronomic data clearly discriminated the M. minima populations. For morphological characterization, the two principal components (PC1 and PC2) explained 84.85% of the total variation and for agronomic evaluation, they describe 79.79%. The large variability observed in all traits studied gives the opportunity to select a suitable plant material to exploit to regenerate degraded rangeland and crop-livestock farming systems in Algeria.

A prime objective for improving perennial grasses for Mediterranean environments is the identification and selection of genotypes well adapted to semi-arid conditions. This study was conducted at an experimental site in Algeria over three consecutive seasons, with the aim of evaluating the agronomic performance and genetic diversity of 13 cultivars of two species of perennial grasses: six cocksfoot (Dactylis glomerata L.) and seven tall fescue (Festuca arundinacea Schreb. = syn.Lolium arundinaceum (Schreb.) Darbysh.) cultivars. Variation was found in both species for dry-matter yield, sward recovery, heading date, water-use efficiency (WUE), and summer senescence. Tall fescue cultivars gave greater yield in spring, with earlier heading date and higher WUE than cocksfoot, with no differences for the other traits. Among the genotypes, `Flecha' was the most promising, together with `E-542', `Fraydo' and `Centurion', all of which are tall fescue cultivars. Principal component analysis indicated that persistence of grass cover is relatively independent from dry-matter yield and water-use efficiency. The level of genetic diversity within each species was assessed using AFLP markers, and the molecular variation was analysed together with agronomic trait variation, with identification of molecular markers potentially associated with the relevant traits

Recently, drought stress became more frequent and this presents a serious challenge for plant breeders to create tolerant barley genotypes with good stability under water deficit conditions. The present study aims to evaluate the effects of water deficit stress with 20% of maximum soil water capacity at heading stage on the physiological traits of some barley genotypes and to set recommendations on their possible use in drought tolerance breeding programs. The results revealed significant differences between genotypes in all tested traits. In this regard, Rahma and Tissa maintained a high relative water content and cell membrane stability under water deficit stress, respectively. These characteristics present effective mechanisms to face drought stress in semi-arid regions. Jaidor was the most stay-green genotype characterized by maintaining a high level of chlorophyll content after water deficit stress treatment. Moreover, Acsad176 accumulated high soluble sugars content as a response to water deficit stress. These genotypes could be considered as potential sources of genes for selection of drought tolerant barley varieties.