Investigation of genetic parameters and general combining ability of genotypes  of tall fescue

Shah-nazari, Marzieh; Siyahsar, Boratali; Khayamnekoei, Seyed-mojtaba; Mohammadi, Reza

Investigation of genetic parameters and general combining ability of genotypes of tall fescue

Document Type : Research Paper

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Abstract

Objectives of the study were to assess general combining ability on fifty genotypes of tall fescue. During 2006, the genotypes were sown in the nursery polycross. Polycross seeds were sown based ob a randomized complete block design with 3 replications to evaluategeneral combining ability of several traits in tall fescue during 2007. Analysis of variance showed significant differences among the genotypes for most of the studied traits. The highest coefficients of variation were obtained for forage dry yield, forage fresh yield, number of stems and rust resistance. Least coefficients of variation were obtained for crown diameter per plant, plant height and peduncle length. Broad-sense heritability was very high for forage dry yield, forage fresh yield, number of stems, crown diameter per plant and plant height. Genetic advance was optimistic for dry yield, forage fresh yield and number of stems. Cluster analysis classified the genotypes into three groupes. Using principal components analysis, the first three components determined 78/80% of the total variance. GCA for trait forage dry yield, forage fresh yield, number of stems, crown diameter per plant were the most important traits in the first component. The highest values were observed for GCA on 9 genotypes for forage dry yield and forage fresh yield, 10 genotypes for crown diameter per plant, 5 genotypes for plant height and 5 genotypes for peduncle length. Thus, selecting genotypes for the characters must be effective in achieving suitable parent for producing synthetic variety

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