Agronomic Evaluation and Utilization of Red Clover (Trifolium pratense L.) Germplasm

Abstract

Germplasm collection as a source of variability and genetic diversity must be evaluated for an efficient management and effective utilization. This research was aimed to evaluate the agronomic value of red clover germplasm collection, to group the cultivars and population according to their morpho-agronomical traits, and to select valuable materials for future breeding programs. Thirty red clover cultivars and populations of different geographical origin were included in the study. Investigation was carried out at the experimental field of the Agricultural Institute Osijek in Croatia. The field trial was arranged in a randomized block design with four replications. Each plot included twenty spaced plants (50 x 50 cm) of each cultivar/population. During two consecutive years (2006, 2007) the following data were collected: yields of green mass, dry matter and seed (g/plant), plant height (cm), dry matter content (%), persistence (%), flowering time. The analysis of variance was carried out for all the traits, with the exception of seed yield and flowering time (which were not recorded as replicated data), using PROC GLM of SAS 9.1. Differences among cultivars/populations were highly significant for all analyzed traits. Hierarchical cluster analysis (Ward method) based on the seven morpho-agronomic traits allowed the identification of six groups of red clover cultivars/populations. This research shows that there is a great genetic variability in the investigated germplasm collection. The most promising materials were selected to form a new breeding gene pool that could be helpful for the improvement of our red clover breeding programme.