Investigation of genetic diversity of forage yield and morphological traits in tall fescue (Festuca arundinacea Schreb.) populations

Tall fescue (Festuca arundinacea) is one of the most important forage plants in the Gramineae family. Due to its resistance to salinity, drought, heavy metals, excessive grazing, as well as preventing soil erosion, tall fescue can be an appropriate choice for large-scale cultivation in Iran because of recent droughts and declined rangelands area. In the present study, the genetic diversity of 90 tall fescue populations was evaluated using 10 morphological and yield related traits including; canopy diameter, days to flowering, days to pollination, plant height, panicle length, collar diameter, number of stems, leaf length, dry forage yield and seed yield in Basmanj region, Tabriz (East Azerbaijan), Iran, during 2015 to 2017. According to the mean of the populations,there were significant differences (p < 0.01) among populations for all of studied traits except for canopy diameter. The results of correlation coefficients revealed that the number of stems, peduncle length, collar diameter and canopy area had a positive and significant correlation with dry forage and seed weight. The heritability of all studied traits was moderate to high. The highest heritability was related to seed yield, dry forage yield and flowering date, respectively. Based on the results of cluster and principal component analyses, studied tall fescue populations were divided into two main groups of ornamental and forage and four clusters (clusters I and II including early- and late-maturing forage populations and clusters III and IV including ornamental populations). The cluster IV included ornamental populations showed the highest difference and genetic distance with cluster I including forage populations and then more heterosis is expected by realizing cross between them. The results showed that the populations investigated in this study had the necessary diversity to running tall fescue breeding programs and can be potentially used in future breeding programs of this plant.