THE VARIABILITY OF THE MORPHOLOGICAL TRAITS OF TETRAPLOID 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 22 tetraploid red clover cultivars, as well as their impact on productivity and the quality of the forage. In the breeding programmes carried out at Cluj-Napoca, in order to improve the morphological traits responsible for green matter yields, it is recommended that cultivars from Central and Western Europe should be used (subvar. intermedium).Within this sub-variety, the Temara cultivar originating from Switzerland was particularly noticed, because of its 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.