A BIBLIOGRAPHIC STUDY ON GENETIC PROGRESS IN THE SPECIES MEDICAGO SATIVA PUBLISHEDDorin GAITIN, Ionel SAMFIRA
Alfalfa (Medicago sativa L.) has been the main forage crop in Romania: the area cultivated with alfalfa cultivars oscillated, between 1938 and 2008, between 136,300 and 442,000 ha, i.e. 29.7-31.6% of the forage crop structure, or 4.8-5% of the arable land. Romania ranges among the largest alfalfa cultivating countries after the U.S.A., Argentina, and Italy (Anuarul Statistic al Romaniei, 1938-2008). In this context, it is important to increase the nutrient value of forage crop cultivars (to improve the content of digestible dried matter, particularly digestible protein and soluble sugars) (Schitea et Varga, 2007). The annual area cultivated with alfalfa cultivars in Romania ranges between 400,000 and 500,000 ha of pure alfalfa cultivars crop, and reaches about 1,000,000 ha of alfalfa cultivars mixed with other species of perennial gramineae. Alfalfa forage is noted for its high content of nutrients varying between wide limits depending on vegetation (Moisuc, 1991). In fact, alfalfa is a great water lover, and drought resistance comes from its capacity of developing a root system as rich and deep as possible and from its ability of overcoming hydric stress periods and of recovering quickly after the hydric deficit ceases (Ittu et Varga, 1975; Ittu et al., 1978). The advantages of cultivating alfalfa cultivars are numerous: it is a perennial legume, it can be exploited for 3-5 year, it yields highly (14-20 t dry matter per ha, in an intensive system), it has a high content of crude protein (19-20% crude protein of the dry matter); in addition, it plays a very important role in crop rotations, as improving sole, leaving in the soil important amounts of nitrogen fixed symbiotically (Varga et al. 1998). Improving forage quality was a very important objective in alfalfa cultivars improvement through the selection of genotypes with rich foliage, short internodes and fistulous shoots.
Medicago sativa, alfalfa, genetic progress, breeding features, hay production