THE VARIABILITY OF THE MORPHOLOGICAL TRAITS OF DIPLOID RED CLOVER CULTIVARS STUDIED IN CLUJ-NAPOCA ENVIRONMENTAL CONDITIONS

The valuable characteristics of red clover (productivity, resistance to biotic and non-biotic factors, as well as quality) depend on a series of morphological and physiological traits, which, in turn, are influenced by genetic and environmental factors. The purpose of our research, carried out at Cluj-Napoca, was to study the variability of the morphological and physiological traits of 45 diploid red clover cultivars, as well as their impact on productivity and the quality of the forage. In the breeding programmes carry out at Cluj-Napoca, in order to improve the morphological traits responsible for green matter yields, recommend that cultivars from Central and Western Europe should be used (subvar. intermedium). Were noticed, within this subvariety, the cultivars originating from Switzerland (Renova, Ruttinova), because of their increased earliness and good after-cut regeneration capacity. The late North-European cultivars (var. serotinum) are valuable for increasing the leaf percentage and cold resistance. It was noticed that cold resistance is a characteristic of this variety and that there is no obvious variability among the cultivars from that area. The cultivars with very good resistance to mildew powder were those from southern Europe (subvar. praecox); this characteristic is one of the most important goals of the breeding programmes in the origin area, given the specific climatic conditions (increased soil and air drought).