RT Journal T1 DECIPHERING THE CHANGE IN ROOT SYSTEM ARCHITECTURAL TRAITS UNDER DIFFERENT NITROGEN REGIMES IN WHEAT (Triticum aestivum L.) A1 Rubab Iqbal A1 Aysha Kiran A1 Muhammad Ramzan Khan A1 Muhammad Shahbaz A1 Abdul Wakeel JF Journal of Animal and Plant Sciences JO JAPS SN 1018-7081 VO 36 IS 6 YR 2026 FD 2026 DO DOI https://doi.org/10.36899/JAPS.2026.6.0150 AB

Root system architecture (RSA) plays a critical role in plant adaptation to varying nitrogen (N) availability by influencing soil exploration, nutrient acquisition, and plant growth. To investigate the diversity of RSA responses to contrasting N availability, a diverse panel of 453 wheat genotypes, including landraces, historical cultivars, and modern varieties, was evaluated.cultivars, exotic cultivars, gene pool accessions and advanced wheat breeding lines and were assessed in controlled glasshouse conditions. A completely randomized design with three biological replicates was used to phenotype the RSA at the tillering stage under two N doses N50 (60 kg N ha⁻¹), corresponding to 50% of the recommended N application rate and representing half of the recommended N availability, and N100 (120 kg N ha⁻¹), corresponding to the recommended field N application rate. Broad sense heritability of platform traits ranged from 0.50 for shoot fresh weight  to 0.83 for the root volume. The N regimes showed contrasting relationships between biomass and RSA traits in a correlation analysis. The shoot biomass correlated positively with root traits, although not strongly, under N50, indicating a greater tendency to invest in root growth rather than shoot growth under low nitrogen availability. Contrary to this, positive trends between shoot biomass and RSA traits were observed under N100, indicating enhanced functional integration of root and shoot growth at N100 levels. Under N100, total root length had stronger positive correlations with both root surface area and root branching, indicating the more coordinated and efficient root system organization under optimal N availability. The genotypes were categorized as superior, intermediate and poor performing plants based on the RSA Index (RSAI) and Total Plant Biomass (TPB) under N50. Several genotypes like WATAN, CHIRYA-3, 1PFAU, M07_FRET-1, MEHRAN-89 and Fakhr-e-Sarhad remained in the top 20% in all the trials and showed better root architecture and biomass production under N deficient conditions. Genotypes such as Chakwal-50, BORLAUG-16, HUW-234, EXCALIBUR, and CS/TH exhibited vigorous root system under the evaluated nitrogen conditions. The genotype SC consistently ranked among the lowest performers, reflecting poor adaptation to low-N environments. The overall genetic variability for these RSA traits under contrasting N regimes indicated that root architectural traits could be valuable selection criteria for the development of wheat cultivars with improved adaptation and productivity under reduced N inputs.

K1 Nitrogen treatments, root imaging, rhizovision, wheat, multivariate analysis. PB Pakistan Agricultural Scientists Forum LK https://thejaps.org.pk/AbstractView.aspx?mid=2026-JAPS-755