Diallel analyses for dry forage yield among some alfalfa cultivars

The objective of this study was to develop population hybrids by crossing five alfalfa cultivars of different geographic origin (Ghareh Yonjeh, Hamedani and Mahalie-Esfahan from Iran, Elchi from Turkey and Ordobad from Azerbaijan) and assessment of combining ability among them using diallel analysis. A half diallel was performed during 2012 between the selected cultivars. For each pairwise cross, ten plants were chosen at random to obtain F1 generation. Heterotic responses were determined by evaluation forage yield of the cultivars and their 10 half-diallel hybrids in seeded plots that were harvested three times in each of 2 years (2014 and 2015). Variation among crosses was attributed primarily to general combining ability (GCA) effects. However, specific combining ability (SCA) effects were also significant. Midparent heterosis ranged from 7.1% in the Elchi x Hamedani to -9.9 % in the Ghareh Yonjeh x Mahalie-Esfahan and high-parent heterosis ranged from 3.4 % in the Elchi x Hamedani to 16.7% Ghareh Yonjeh x Mahalie-Esfahan. Results indicated that Elchi cultivar could be considered as a member of a potential heterotic group for adapted cultivars (Ghareh Yonjeh and Hamedani) to the studied environment.