Asian Journal of Agricultural Sciences 4(5): 346-351, 2012 ISSN: 2041-3890 © Maxwell Scientific Organization, 2012 Submitted: June 28, 2012 Accepted: July 31, 2012 Published: September 25, 2012 Corresponding Author: N. Khan, Department of Genetics, University of Karachi, 75270, Pakistan, Toronto, Canada 346 Correlation and Path Coefficient Analysis in Wheat Genotypes under Irrigated and Non-Irrigated Conditions N. Khan and F.N. Naqvi Department of Genetics, University of Karachi, 75270, Pakistan, Toronto, Canada Abstract: Current research was conducted with the objectives to identify the utmost traits that may be beneficial for the higher productivity of the grains under stress environment. Research material consisted of thirteen genotypes which were obtained from different sources. Experiment was carried out in randomized complete block in a split plot design. Water regimes (irrigated and non-irrigated) were allocated to the main plots and genotypes to the subplots. Path coefficient could be used as an important tool to bring about appropriate cause and effects relationship between yield and yield components. According to obtained results the selection on the basis of number of spikes, number of spikelet’s and number of grains in this material would likely to be most useful for increasing grain yield because of their direct positive contribution to grain yield under irrigated condition. However number of spikes, spikelet numbers, spike length and grains number may be used an effective selection criterion for increasing grain yield of wheat under different irrigation levels. Therefore it is concluded that these traits could be selected for the different stress environments and it would be beneficial for the yield. Keywords: Agronomic traits, correlation coefficient, path coefficient, wheat INTRODUCTION Wheat (Triticum aestivum) is an important Rabi food crop in Pakistan. Being a staple food, wheat has occupied a lot of area in Pakistan. The need and importance of wheat is increasing day by day due to increase in human population. Abiotic stresses limit crop productivity (Boyer, 1970; Araus et al., 2002). Among various biotic stresses drought is undoubtedly one of the worst natural enemy of life. It can occur in any region of the world and can affect life from very basic personal inconvenience to nationwide. Drought can reduce crop yield, pasture deterioration and death of livestock. It strongly affects the production of cereals and poses a serious threat to the food security of households. World food security is dependent on continuous crop improvement; in particular, the development of crops with increased tolerance to abiotic stresses especially drought and salinity (Denby and Gehring, 2005). Yield is a complex quantitative trait, considerably affected by environment. Therefore, selection of genotypes based on yield is not effective. Selection has to be made for the components of yield. Bhatt (1972) reported that only correlation studies not clearly reveal such sort of information and inadequate knowledge interrelationships of heritable traits may lead to negative results. On the other hand, path coefficient analysis measures the direct and indirect effect for one variable upon another and permits the separation of the correlation coefficient into components of direct and indirect effect (Dewey and Lu, 1959). Path analysis focused direct and indirect effect of component traits on yield. With these objectives, present study was carried out to detect correlation and path for increased yield in wheat under irrigated and non-irrigated conditions. MATERIALS AND METHODS Plant materials: The experimental material comprised of thirteen wheat genotypes included eleven advanced wheat lines, one synthetic hexaploid and their durum parent which were provided by CIMMYT, Mexico and NARC, Islamabad, Pakistan. Water stress imposed by withholding irrigation, were as follows: Control plants were watered regularly and never allowed to dry out whereas tillering stress was imposed at 38 days after sowing and continued till 47 days after sowing or completion of tillering. Stress was also imposed before anthesis began in each genotype (avoiding spikes with any sheded pollens), with subsequent irrigations at intervals of fifteen days till harvesting and was named as anthesis stress. Grain-filling stress was imposed after anthesis and continued till harvesting. Plants were watered at fifteen days intervals during this period. All the genotypes were grown in the screen house of Genetics department, University of Karachi. Data was recorded for the year 2006-2007. Experiment was repeated twice. Experiment was carried out in a randomized complete block in a split plot arrangement.