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 semi-hydrophonic 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 well-spred 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.

Genotypic dependence of wheat species in nitrogen uptake determines by root morphology at maturity

“…At maturity, spelt produced 59% and 67% of greater root length than bread wheat and emmer, respectively. Fernando et al (2021) found that two weeks old seedlings of emmer had wider emergence angles and tip angles in seminal roots than spelt, bread wheat and einkorn. According to the results of the present study, emmer genotypes developed shallow root systems at maturity.…”

“…After that, WinRHIZO regular V.2002c software was used to analyse all scanned root images (Fig. 4C) (Fernando et al 2021). Following scanning, roots together with shoots were oven-dried at 80 o C for 48 hours before determining their dry weight.…”

Influence of Sediment, Plants, and Microorganisms on Nitrogen Removal in Farmland Drainage Ditches

“…From April to June, the nitrogen removal rate increased rapidly with increases in temperature. This was because appropriate high temperatures facilitate the microbial nitrification and denitrification reactions for removing nitrogen from the ditches [32]. From June to August, the purification rate of plants and microorganisms showed an oscillating trend with increases in temperature, which was due to the sensitivity of plants and microbial growth to external factors [32,33].…”

“…This was because appropriate high temperatures facilitate the microbial nitrification and denitrification reactions for removing nitrogen from the ditches [32]. From June to August, the purification rate of plants and microorganisms showed an oscillating trend with increases in temperature, which was due to the sensitivity of plants and microbial growth to external factors [32,33]. At high temperatures, the growth of plants, as well as the nitrification and denitrification of microorganisms were inhibited to a certain extent, thereby decreasing the nitrogen removal rate; moreover, the microbial population may reach a peak at this time due to the nutrients in the substrate that may not be sufficient to sustain the growth of the population, leading to a dynamic equilibrium [34,35].…”