Study of Relationship Between Some Agro-Morphological Traits With Yield in M7 Generation of Soybean Mutant lines Irradiated by Gamma Ray

thirty-three M7 soybean mutant lines which originated by ray (co-60) fromcultivar L17 irradiated with doses150, 200 and 250 Gray (absorbed dose), L17 cultivarand two commercial cultivars; Clark (CL) and Williams (WI) were evaluated in view ofsome agronomical and morphological traits under completely randomized design withthree replications. In M7 mutant lines all traits except number of seed per pod showed asignificant difference at =1% or 5% in comparison with L17 and commercial cultivars.The difference of seed per pod was not significant amongst studied lines. Seed yield perplant showed positive and highest correlation (0.886) with harvest index. Stepwiseregression analysis showed 99.7% variation of yield per plant as a depended variablejustified with harvest index and plant dry weight traits that harvest index value weremore than plant dry weight. By using forward regression analysis except two mentionedtraits other traits with low importance including number of leaf per plant, plant heightand root dry weight were inserted in final regression model. Path analysis resultsshowed that harvest index and plant height have respectively highest (0.6) and lowest(0.001) positive direct effects on seed yield per plant. Therefore harvest index trait canbe used as relevant selection criteria for yield in plant breeding programs. By using ofprincipal factor analysis with varimax rotation for studied traits, 6 factors weredetermined that these factors justified 89% of total variation. First factor justified 35%of total variation and this factor called as a yield factor.