Variation in yield, forage quality and morphological traits of red clover (Trifolium pratense L.) breeding populations and cultivars

Abstract

The main objectives of this study were 1) to estimate variation in yield, forage quality and morphological traits of newly developed red clover (Trifolium pratense L.) breeding populations of different origin, 2) to compare their yield potential with foreign cultivars, 3) to determine the relationship between studied traits and 4) to identify and select the most promising populations for future breeding work. Eight red clover breeding populations of different origin (OPCD-2, RCOP-1,3,4,5,6,7,8 created within the framework of the forage crops breeding program at the Agricultural Institute Osijek, Croatia) and eight foreign cultivars (‘Liepsna’, ‘Kamaniai’, ‘Nosovskij 5’, ‘Pallas’, ‘Astred’, ‘Redquin’, ‘Milvus’, ‘Amos’) were evaluated for thirteen morpho-agronomic and forage quality traits. Field experiment was designed as a randomised complete block with three replications over two consecutive years (2008 and 2009) at the Agricultural Institute Osijek, Croatia. The studied breeding populations/cultivars of red clover significantly varied in yields of green mass and dry matter, plant height, number of internodes, density of hairs, width and length of central leaflet, shape of medial leaflet, leaf to stem ratio, content of crude protein and relative feed value. Croatian breeding populations RCOP-3, OPCD-2 and RCOP-1 had significantly higher total yields of green mass (from 98.50 to 111.82 t ha -1 ) and dry matter (from 22.61 to 25.64 t ha -1 ) compared to the observed yields of other populations and foreign cultivars of red clover, which indicates their high genetic potential for yield. Besides the high forage yield, those breeding populations achieved favourable values of quality and other analyzed morphological traits, and they are representing valuable germplasm for further selection work and improving of our breeding program and/or application for plant cultivar registration. Positive correlations were found between forage yields and plant height, number of internodes and between width and length of central leaflet, and these properties were positively correlated with each other. Most quality traits were in negative correlation with yield and other observed morpho-agronomic traits.