ESTABLISHMENT OF PHENOTYPIC VARIABILITY AND CORRELATIONS OF SEED YIELD AND YIELD RELATED TRAITS IN ALFALFA ( Medicago sativa L.) CLONAL PROGENIES

The aim of present study was to evaluate phenotypic variability of seed yield and yield-related traits and to establish the relationships among them at eleven alfalfa clonal progenies. The study was conducted in experimental field at Institute of Agriculture and Seed Science Obraztsov chiflik - Ruse under conditions of open pollination (polycross), from 2014 to 2016. The traits plant seed yield, plant height, generative stem number, inflorescence number, pod number, seed number and 1000-seed weight were evaluated. The main effect and second interaction (year, genotype and year x genotype) had a significant influence on all morphological and generative traits. There was wide range of variability for all analized traits between progenies and over study period. PM30 progeny showed superior scores regarding all traits studied and four progenies distinguished with high phenotypic expression of seed yield, pod number, seed number and 1000seed weight. The seed yield obtained was in range from 2.45 to 3.44 g plant-1. These progenies are valuable germplasm source to be used in further breeding to develop a new synthetic alfalfa variety with stable seed yield. It was found seed yield strongly and positively correlated with plant height (rp=0.752**), pod number per inflorescence (rp=0.700**) and seed number per pod (rp=0.611**), which suggest that selection for improving alfalfa seed yield may be performed directly through selection on these three traits.