Path Analysis of Grain Yield and Yield Components and Some Agronomic Traits in Bread Wheat

JANMOHAMMADI MOHSEN, SABAGHNIA NASER, NOURAEIN MOJTABA. 2014. Path Analysis of Grain Yield and Yield Components and Some Agronomic Traits in Bread Wheat. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 62(5): 945–952. Development of new bread wheat cultivars needs effi cient tools to monitor trait association in a breeding program. This investigation was aimed to characterize grain yield components and some agronomic traits related to bread wheat grain yield. The effi ciency of a breeding program depends mainly on the direction of the correlation between diff erent traits and the relative importance of each component involved in contributing to grain yield. Correlation and path analysis were carried out in 56 bread wheat genotypes grown under fi eld conditions of Maragheh, Iran. Observations were recorded on 18 wheat traits and correlation coeffi cient analysis revealed grain yield was positively correlated with stem diameter, spike length, fl oret number, spikelet number, grain diameter, grain length and 1000 seed weight traits. According to the variance infl ation factor (VIF) and tolerance as multicollinearity statistics, there are inconsistent relationships among the variables and all traits could be considered as fi rst-order variables (Model I) with grain yield as the response variable due to low multicollinearity of all measured traits. In the path coeffi cient analysis, grain yield represented the dependent variable and the spikelet number and 1000 seed weight traits were the independent ones. Our results indicated that the number of spikelets per spikes and leaf width and 1000 seed weight traits followed by the grain length, grain diameter and grain number per spike were the traits related to higher grain yield. The above mentioned traits along with their indirect causal factors should be considered simultaneously as an eff ective selection criteria evolving high yielding genotype because of their direct positive contribution to grain yield.