Root System Architecture and Nitrogen Uptake Efficiency of Wheat Species

Abstract

Purpose : Plant nitrogen use efficiency can be increased by improving N uptake efficiency (NUpE). Root system architecture of the plant plays a vital role in uptaking water and nutrients including N. The present study was conducted to compare root architectural traits of different wheat species at early seedling development and vegetative growth stage while plant nitrogen uptake at vegetative and mature stages under controlled environment. Research Method : Ten genotypes belong to four wheat species; einkorn, emmer, spelt and modern bread wheat were compared. Growth pouches were used to develop root systems of seedlings and images were analysed by using RootNav software. Root charcteristics and above-graound growth at vegetative growth phase was studied using semihydrophonic system where WinRhizo software was used to analyse root images. Finally, glasshouse pot experiment was conducted to calculate NUpE at maturity. Findings : The highest number of seminal roots, total root length and wider tip angle of seminal root were recorded in emmer. However, total root length was not significantly different from spelt cv. Oberkulmer. Genotypes with narrow and wide tip angles of seminal roots produced deep and shallow seedling root systems, respectively. Positive relationship between root traits and nitrogen uptake at the vegetative growth stage was found. Fertiliser NUpE of ancient wheat species varied significantly among genotypes where emmer recorded the highest value followed by spelt, bread wheat and einkorn. Originality/ Value : Wheat species varied for seedling root system architecture. Emmer had wide and shallow seedling root systems while having high NUpE at maturity. It suggests the importance of a wellspred shallow root system to uptake N fertiliser rapidly before leached down. Further, emmer is an ancient wheat species with an ability to uptake N efficiently which suggests that when bread wheat was selected for high yield, favourable root traits related to NUpE might be neglected. Favourable root traits in emmer related to NUpE could be introduced to bread wheat through the direct crossing or creating synthetic wheat.