Identification of Nitrogen Efficient Indica Rice (Oryza sativa L.) Genotypes: A physiological and Multivariate statistical approach

Nitrogen efficiency (NE) is an important approach to develop nitrogen use efficient (NUE) genotypes in rice growing regions globally. Identification of nitrogen (N) tolerant genotype is the foremost step to develop Nitrogen Use Efficient (NUE) genotypes. In order to identify the N tolerant genotypes in popular indica rice a hydroponic experiment was conducted in glass house with various concentrations of N and 26 genotypes were screened by measuring growth dynamics, biomass accumulation and NE traits. The data revealed that growth dynamics viz., morphological (TNL, RL and SL), biomass (RFW, SFW, RDW, SDW and TDM) and NE traits showed high genotypic variation for N treatments. Of which root and shoot traits were significantly influenced the nitrogen efficiency trait of genotypes. Based on NE; genotypes were categorized as High Efficient; Medium efficient and Low efficient genotypes. Growth dynamics and NE traits were higher in DRRH3 at low N condition; while BPT5204 responds very poor under low N which confirmed that DRRH3 as most N-efficient and BPT5204 as most N-inefficient genotypes. Further experimental data was subjected to multivariate statistical analysis by means of Pearson correlation, PCA and hierarchical clustering of heatmap analysis. The statistical data is in tune with the experimental data and strongly supported that root and shoot traits are most contributing traits for NE of genotypes. The data generated in the present study is very useful for the selection of genotypes as parents for the development of NUE genotypes of rice.