THE MORPHO-PRODUCTIVE CHARACTERIZATION OF THE PERENNIAL RYEGRASS GERMPLASM IN THE WESTERN PART OF ROMANIA

Perennial ryegrass-dominated grassland ecosystems are typically stable in terms of resilience, as persistence is an important evaluation criterion in perennial breeding programs. The aim of the study was to analyze the morpho-productive characterization of the germplasm collection of the perennial ryegrass collection to identify local provenances that exceed in phenotypic expression under current cultivation conditions in the western part of Romania. For that, numerous observations were made regarding the dynamics of the following traits: plant height (cm), number of leaves per plant, leaf width (cm), leaf length (cm) and the number of shoots. The biological material was made up of local provenances of Lolium perenne collected from three geographical areas: the Almaju Mountains, the Mehedinți Plateau and the Blahniței Plain. From the analysis of the correlation relationships highlighted between the five morpho-productive traits investigated, it can be observed the determining role of the height of the perennial ryegrass plant in the dimensioning and phenotypic expression of the traits. Thus, the height of the plant is in a direct interdependence relationship with traits such as the number of leaves per plant and the length and width of the leaf. These interdependencies are subject to the bio-morphological composition of the grass species in which the stem comprises nodes and internodes, and a leaf leaves from each node. In other words, the taller the plant is and the more nodes it has, the more leaves it has. The distinctly significant correlation relationship between the number of leaves per plant and the number of shoots where the growth in the form of a bush in perennial ryegrass explains this high correlation is also highlighted. The study provides a detailed analysis of linear regressions for different morpho-productive traits plant height (cm), number of leaves per plant, leaf width (cm), leaf length (cm) and number of shoots, with the aim of understanding how the collected genotypes influence these traits.