Using double and triple biplots for the identification of the superior winter wheat genotypes with elevated performance for root traits, yield and yield components for rainfed conditions

Sadegh Ghol Moghadam, Ramin; Saba, Jalal; Shekari, Farid; Roostaei, Mozaffar

doi:10.22124/cr.2025.28331.1834

Using double and triple biplots for the identification of the superior winter wheat genotypes with elevated performance for root traits, yield and yield components for rainfed conditions

Document Type : Research Paper

Authors

¹ PhD graduate

² zanjan university

³ Wheat Breeder and head of cereal recherch department

10.22124/cr.2025.28331.1834

Abstract

Introduction
Selection and breeding to increase yield always has been one of the main goals of wheat breeders. Since the yield of rainfed wheat is dependent on the moisture stored in the soil during the rainy season, therefore, in different regions, adapted cultivars for each region should be evaluated in terms of the potential of using the water stored in the soil during long periods of drought. Roots are the main organs to respond, understand and maintain yield in drought conditions, which are known as the hidden half of the plant and their function plays an important role in the growth and yield of plants. On the other hand, selection based on multiple traits increases the suitability of crop varieties for farmers. genotype×trait (Jia et al.) and triple genotype×yield×trait (Faheem et al.) biplots are graphic methods that have been presented to evaluate and identify favorable genotypes in terms of several traits.

Materials and methods
In this study, 11 varieties of rainfed winter wheat along with 13 advanced lines of bread wheat were cultivated and evaluated in the form of a completely randomized block design with three replications in the research farm of the Faculty of Agriculture of Zanjan University during the two crop years of 2016-2017 and 2017-2018 under rainfed conditions. In this research, two genotype x trait (Jia et al.) and genotype x yield x trait (Faheem et al.) plots were used to identify the relationship between root traits and grain yield and yield components and to select the best wheat genotypes based on multiple traits.

Research findings
The results showed that using GYT biplot is more efficient than GT biplot. Based on GYT biplot and superiority index (Bakhshi et al.), genotype 2 was identified as the superior genotype considering all yield-trait combinations except yield- root length and surface greater than 25cm deep. Genotypes No. 10 and 11 were favorable genotypes in terms of yield combination with root length and surface greater than 25cm deep. In the GYT method, root penetration depth, number of spikes per square meter, root diameter to a depth of 25cm, and after them thousand kernel weight, root volume, length, dry weight and root surface to a depth of 25cm and root diameter greater than 25cm deep are important traits for determining the genetic gain in breeding programs and considering these traits, genotype 2 was identified as the closest genotype to the ideal genotype.

Conclusion
The results of this research showed that there is potential for simultaneous genetic improvement of root traits, especially in the surface part of the soil along with grain yield in wheat. Based on the obtained results, it can be said that the GYT graphic method is a new efficient and practical method to identify superior genotypes based on multiple traits in breeding programs.

Keywords