Evaluation of Morpho-Physiological Diversity of Durum Wheat Genotypes using Genotype x Trait Biplot Method

The primary goal of the plant breeding program is to evaluate the genotypes based on different traits and select the best genotypes based on the studied traits. The aim of this study was investigation of durum wheat genotypes diversity based on agro-physiological traits and study the interrelationships between the traits using the genotype x trait (GT) biplot technique.

In this study, 86 durum wheat genotypes, including 82 breeding lines received from CIMMYT along with four check genotypes were examined as an augmented design in the Dryland Agricultural Research Sub-Institute (Sararoud Station) during 2017-18 crop season. Genotypes were evaluated based on 22 different agronomic, morphological and physiological traits. Analysis of variance and comparison of genotypic means were performed based on the best linear unbias prediction (BLUP) method and then based on the BLUP data, the GT biplot analysis was performed.

Based on the results, a significant difference was observed between the studied genotypes in terms of all studied traits except for canopy temperature and spike length, which indicates a significant genetic diversity between genotypes for the studied traits. Based on the representation of polygon view of the GT biplot, the genotypes were divided into eight groups and the traits into six groups. Genotype #17 had the highest value in terms of combination of grain yield, biological yield, harvest index, 1000-grain weight and relative chlorophyll content index (SPAD-reading). Genotype #3 had the best combination of plant height, number of grains per spike, initial growth rate, spike length, relative leaf water content and flag-leaf length. Genotype #27 had the highest values ​​in terms of canopy temperature and peduncle length and genotype #76 had the highest value in terms of canopy temperature compared to other genotypes. Genotype #4 had the highest combination of traits number of days to booting and external peduncle length. Genotype #10 had high values ​​in terms of number of days to physiological maturity and number of spikes per square meter, which is a late genotype in this regard. Based on the results of correlation analysis and GT biplot analysis, biological yield, harvest index, 1000-kernel weight, SPAD-reading, number of spikes per square meter were identified as the most important traits affecting grain yield.

Based on selection criteria, genotypes # 75, 17, 72, 13, were identified as ideal genotypes under rainfed condition and are recommended for further studies in durum wheat breeding program.