Assessment of Relationships among Yield and Quality Traits in Alfalfa (Medicago sativa) under Dryland Farming System, Hamadan, Iran

Seeds of 200 accessions of alfalfa (Medicago sativa L.) were provided from Iranian natural resource gene bank and were sown as drilled plot using alpha designs/unreplicated with 2 repeated entries within all of 10 blocks under dry land farming system in agricultural research center of Hamadan, Iran during 2009 to 2010. The data were collected and analyzed for plant height, stem number, leaf stem ratio (LSR), node number, vegetation score, forage dry matter yield (DM yield), crude protein (CP), dry matter digestibility (DMD), water soluble carbohydrates (WSC), crude fiber (CF), acid detergent fiber (ADF), and total ash. DM yield was positively correlated with node number, plant height, stem number, vegetation score and negatively correlated with leaf/stem ratio, DMD(%), CP(%)and WSC(%). The factorial analysis was based on the principal component extraction and varimax rotation method. Results of factor analysis were accounted for 81% of total variance for first six factors. Factor 1 which was accounted for 19% of variation was associated with DMD, WSC and ADF. This factor was regarded as quality factors. Factor 2 accounted for 17% of variation was named as the productivity factor since it included DM yield, vegetation score and leaf/stem ratio. Since the third (CP and CF) and forth factors (plant height and node number) were important. Based on ward cluster analysis, 200 entries were divided into 7 groups. Accessions in 4 clusters were calculated well above the overall mean for DMD, CP, WSC and total ash. The accessions in cluster 7 had higher values for DM yield and morphological traits. The results of this study indicate that selection of variables in productivity factor (factor2) could enable breeders to release the desirable increment in forage yield of alfalfa.