To minimize unused nitrogen (N) fertilizer in the soil, improving the nitrogen use efficiency of the cropping system is of utmost importance. Plants mainly absorb N from the soil through roots. The study was, therefore, carried out to know the inheritance pattern of root traits responsible for N uptake. Extreme six spring wheat lines selected from 175 genotypes screened for root dry weight under hydroponic condition were crossed in half diallel to generate 15 F_1s. These F_1s along with their parents were evaluated under hydroponic condition for rooting depth (RD), root surface area (RSA), root volume (RV), total root length (TRL) and numbers of root tips (N tips) under N-limiting and N-non-limiting environment. Combining ability analysis revealed significant contribution due to both general combining ability and specific combining ability for all root traits indicating the importance of both additive and non-additive gene actions under both N environments. However, the relative importance of each was different in the two environments, indicating, therefore, separate breeding strategies for the two environments. Early generation selection for the root traits like RD, TRL, RSA, RV and N tips under N non-limiting can be effectively integrated into the breeding programme as indicated by preponderance of additive gene effects in the study. The distribution pattern of the various roots traits in the F₂ generation of a specific cross indicates the involvement of multiple genes with minor effects for the most of root traits and therefore confirms our earlier observations that selection for the root traits can be effective; however, the stage of selection (early vs. late generation) depends upon the N environment.

为了最大限度地减少土壤中未使用的氮 (N) 肥料，提高种植系统的氮利用效率至关重要。植物主要通过根系从土壤中吸收氮。因此，进行这项研究是为了了解负责氮吸收的根性状的遗传模式。从水培条件下根干重筛选的175个基因型中选出的极端6个春小麦品系以半双列杂交产生15个F _1s。这些 F ₁与他们的父母在水培条件下对生根深度 (RD)、根表面积 (RSA)、根体积 (RV)、总根长 (TRL) 和根尖数 (N 尖) 在 N 限制和 N 下进行评估- 非限制性环境。配合力分析显示，由于所有根性状的一般配合力和特定配合力都有显着贡献，表明在两种 N 环境下加性和非加性基因作用的重要性。然而，每种环境的相对重要性在两种环境中是不同的，因此表明两种环境的育种策略不同。RD、TRL、RSA 等根特征的早期选择 正如研究中加性基因效应的优势所表明的，在 N 非限制条件下的 RV 和 N 提示可以有效地整合到育种计划中。F 中各根性状的分布格局₂代特定交的指示的多个基因的与用于最根性状的影响较小的参与，因此证实了我们的早期观察该选择为根性状可以是有效的; 然而，选择的阶段（早期与晚期）取决于 N 环境。