Genetic variation for and interrelationships among seed vigor traits in wheat from the Caspian Sea coast of Iran

This study was undertaken to examine the interrelationships of several seed vigor traits in wheat (Triticum aestivum L.) through path-coefficient anal ysis, to determine broad-sense heritability, and to estimate genetic advanc e under selection. Germination rate (R50), germination uniformity, percenta ge of normal seedling, seedling dry weight, seed dry weight, seed water con tent, electrical conductivity of seed leachate (membrane integrity), seed r eserve utilization ratio (fraction of mobilized seed reserves) and seed res erve utilization efficiency (conversion efficiency of mobilized reserves) o f 15 wheat genotypes from the Caspian Sea coast of Iran were used for analy ses. The genotypes exhibited significant differences for all traits, except for seed. water content. Genetic correlations among R50, germination unifo rmity and seedling dry weight were not significant, showing that selection for any of them might be possible without hampering any other traits. Howev er, path-coefficient analysis indicated that genetic improvement in fractio n of mobilized seed reserve and conversion efficiency of mobilized reserves would have no beneficial effect on seedling dry weight, since it would be compensated for by indirect negative effects via seed dry weight. Moderate to high estimates of broad-sense heritability, genetic coefficient of varia tion and expected genetic advance were obtained for R50, germination unifor mity, seedling dry weight and membrane integrity, indicating the possibilit y for improving these traits. For successful long-term improvement, crossin g programs between the genotypes studied here and genotypes from other part s of the country or overseas might be necessary.