Selection criteria that can facilitate grain yield improvement would be considered important plant breeding tools. Knowledge on the association of yield with other agronomical traits is essential in understanding the magnitude and direction of changes expected during selection. Correlation and path coefficients were estimated to evaluate the importance of different agro-morphological traits in wheat, to determine the direct and indirect effects of these components on yield, and to develop selection criteria for higher grain yield. Fourteen wheat genotypes (Triticum aestivum L.) were grown under two environments (irrigated and rainfed). The experiment was performed, based on randomized complete block designs (RCBD) with three replications. Mean grain yield in rain-fed conditions was 11.26% lower than that in irrigated conditions. The genotypes Marvdasht and M-81-13 exhibited the highest grain yield per unit area in rain-fed conditions. A highly significant positive correlation between grain yield and grain/spike (r = 0.836**) and also peduncle length (r = 0.698**) was found in water stress conditions. Therefore grains/spike and peduncle length could be used as reliable criteria for selection of bread wheat genotypes for water stress tolerance. Four main factors accounted for 85% of the total variability in the dependent structure. Factors 1, 2, 3 and 4 explained 27.7%, 19.6%, 19.3% and 18.4% of total variation, respectively. The first factor comprised Fv/Fm, spike/m2, stomatal conductance and leaf chlorophyll content. Therefore the factor emphasized on photosynthetic components. The second factor included grain yield, grain/spike, spike/m2, W1000, spike length and spike weight (with positive factor loadings). The suggested name for the factor is yield and yield components. Factor 3, growth characteristics, consisted of biological yield (biomass), plant height, peduncle length and awn length. Factor 4 was named phonological traits because it was significantly affected by days to heading and days to anthesis.
