The phenotypic diversity and productivity of a diverse alfalfa (M. sativa subspp.) panel of cultivars, landraces and wild relatives with putative drought tolerance were evaluated in two Mediterranean environments (central Chile and Southern Australia). In Chile, 70 accessions were evaluated in rainfed conditions and in Australia 30 accessions under rainfed and irrigated conditions, during three growing seasons. Large phenotypic variation was observed among and within subspecies for NDVI, stem length, intercepted PAR and forage yield. Principal component analysis indicated that the first two principal components (PC) accounted for 84.2% of total variance; fall dormancy, taxa, and breeding status were closely related to the agronomical performance of alfalfa accessions. Forage yield varied largely among accessions across years and locations. A linear relationship was found between annual forage yield and annual water added to the experiments (R² = 0.60, p < 0.001). The GxE analysis for forage yield allowed the detection of the highest yielding accessions for each of the two mega-environments identified. The accessions CTA002 and CTA003 showed greater forage yield in both Chile and Australia environments. It is concluded that new breeding lines derived from crosses between cultivated alfalfa (M. sativa subsp. sativa) and wild relatives belonging to the primary (M. sativa subsp. falcata) and tertiary (M. arborea) gene pool, achieve outstanding agronomical performance in drought-prone environments.

The present review examines the main attributes and agronomic characteristics of arrowleaf clover (Trifolium vesiculosum Savi) and its incorporation into production systems in dryland areas of the Andean foothills of the humid Mediterranean climate zone of Chile. It is a new species of annual legume in Chile for light and medium textured soils. The root system can reach a depth of 1.5 m and its seeds have a high percentage of hardseedness (99.8%). It is an upright plant, with purplish-white flowers. The mature plant has large arrow-shaped leaves up to 50 mm long, often marked with a large white “V”. Dry matter and seed production in the Andean foothills is high (3.9-8.8 t DM ha-1 and 700-900 kg ha-1, respectively), surpassing the productivity of sub clover (Trifolium subterraneum L.) cv. Mount Barker and crimson clover (Trifolium incarnatum L.). However, DM production in the second year was lower, possibly because the high percentage of hardseedness inhibited plant emergence. The phenological records and productive performance suggest that arrowleaf clover could contribute to improving pastoral production in dryland areas with annual rainfall levels of more than 800 mm, such as the Andean foothills in the central-southern region of Chile.