Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding CASRP΄s archiving and manuscript policies encouraged to visit: http://www.casrp.co.uk/journals Abstract Selection of genotypes based on high value of heritability and forecasted genetic conditions would be an effective method for improvement of wheat cultivars. The present investigation was carried out to estimate the genetic variability of agro-physiological characters using biometrical genetic techniques in 20 bread wheat genotypes under irrigated condition. For this purpose an experiment was conducted to estimate the genetic parameters of some agro-physiological traits and their relationship with yield under Irrigated conditions. High genetic variability was observed between the genotypes for the characters grain yield (GY), chlorophyll a (Chl a), chlorophyll ab (Chl ab), quantum yield (QY), performance index (PI), relative water loss (RWL) and leaf chlorophyll content (LCC), therefore direct selection is effective for improvement of these traits.Total chlorophyll content (Chl ab), chlorophyll b (Chl b) and PI revealed high heritability and co-heritability with yield. Hence, they can be used as indirect selection for the improvement of yield under irrigated condition.