Genetics analysis of nitrogen use efficiency component traits under nitrogen-limiting environment

Abstract

To address the environmental concerns and increases the total factor productivity to the farmers simultaneously, forces the breeders to develop the genotypes adapted to low input agriculture especially, low nitrogen (N) management practices. However, inadequate knowledge about the genetics of plant response to the low nutrient regime is complicating the breeding procedure. Therefore, the present study was designed to work out the genetics of nitrogen use efficiency (NUE) and its component traits under N-limiting (LN) environment in Indian wheat germplasm. Analysis of variance showed the presence of a large amount of genetic variability for NUE as well as its component traits. Combining ability analysis for N efficiency under LN indicated the importance of both additive and nonadditive gene action in their inheritance. Additive gene action was more important for shoot dry weight, NUE, and maximum root length. Improvement in these traits can be achieved by targeting the selection in early fixed lines (F4–F5) in the breeding population created by crossing good general combining ability (GCA) lines such as DPW 621-50 and HD2967/HD3024. Whereas, root dry weight (RDW), gram N in shoot (gN), nitrogen uptake efficiency (NUpE) are influenced by nonadditive gene effects which can be improved either through population improvement programme or hybrid breeding approach. Recurrent selection can be quite useful in developing the desirable recombinants for RDW, gN, NUpE, and nitrogen utilization efficiency from crosses with high specific combining ability (SCA) effects and involving high × low GCA parents.