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Pak. J. Bot., 47(6): 2093-2105, 2015.

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CAPABILITY OF MULTIPLE SELECTION CRITERIA TO EVALUATE CONTRASTING SPRING WHEAT GERMPLASMS UNDER ARID CONDITIONS

SALAH E. EL-HENDAWY ^1,2*, NASSER A. AL-SUHAIBANI¹, KHALED AL-GAADI³,

AND SHAFIQ UR REHMAN^5*

¹Plant Production Department, College of Food and Agriculture Sciences, King Saud University,

11451 Riyadh, Saudi Arabia

²Agronomy Department, Faculty of Agriculture, Suez Canal University, 41522 Ismailia, Egypt

³Department of Agricultural Engineering, Precision Agriculture Research Chair, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia

⁵Department of Botany, Kohat University of Science & Technology, Kohat, Pakistan

^*Co-Corresponding authors: mosalah@ksu.edu.sa, drshafiq@yahoo.com

Abstract: Selection criteria that would evaluate a large number of germplasm in a rapid and non-destructive manner would be considered advantageous in plant breeding programs. Trade-off between traditional and non-destructive screening criteria in evaluating 90 wheat accessions under water shortage was tested using multivariate statistical techniques. Only three irrigations during the growing cycle of germplasm were applied with the amount of water totalling 2550 m³ ha^-1. Sequential path analysis identified one traditional trait (grain weight per plant) and two non-destructive traits (leaf area index and stomatal conductance) as important first-order traits that influenced final grain yield. The three traits, taken together, explained 96.8% of the total variation in grain yield. Total dry weight per plant, green leaf area per plant, harvest index, grain number per plant, leaf water content and canopy temperature were identified as important second-order traits that influenced grain yield. Although canopy temperature was ranked as a second-order trait, it explained 64.4% of the total variation in stomatal conductance. Approximately 78.0% of the total variation in grain weight or leaf area index was explained by the leaf water content (66.2%) and total dry weight (11.5%). The 90 examined spring wheat germplasms were grouped into five clusters based on all agro-physiological traits using the centroid linkage method. The tested wheat germplasm that produce high grain yield under water shortage were characterised by good performance of certain rapid, easy and non-destructive physiological traits such as high leaf area index, high stomatal conductance and low canopy temperature. Therefore, these three traits could be used in combination as quick and easy screening criteria to select suitable genotypes for water-limiting conditions.

Key words: Canopy temperature; Leaf area index; Phenomics; Sequential path analysis; Stomatal conductance.