NITROGEN USE EFFICIENCY: RELEVANT TRAITS AND INHERITANCE, KEYS TO ENHANCING WHEAT PRODUCTIVITY UNDER LOW N-INPUT

Abstract

Six parents i.e. 1) Line 1, 2) Line 2, 3) Line 3, 4) Sakha 93, 5) Giza 168 and 6) Gemmeiza 10 were crossed in a half diallel to demonstrate performance, important criteria, gene action and heritability for NUE components. Available soil nitrogen 40.5 kg N/fad. was expressed as low N-level (L1), then 35 Kg N/fad was added to give 75.5 kg N/fad which represents the normal N-level (L2) and 70 kg N/fad was added to give 110.5 Kg N/fad as high N-level (L3), were implemented in three adjacent experiments, separately in a RCBD. Parents P1, P2, P6 and F1 crosses P2 x P5 and P3 x P4, P4 x P6 made more efficient use of each amount of nitrogen uptake for grain and straw yield. N-stress tolerance indices showed that P1, P5, P1 x P4, P1 x P5, P3 x P4, P3 x P5 and P5 x P6 were more tolerant to N-deficiency stress. Factor analysis shows that DH, DM, SGD, PH and yield components of first factor had high loading coefficients with highest participation in NUE. Also, SYP, BYP, SRI and NUtE of second factor were important. Hierarchical cluster analysis heatmap illustrated that P2 and P6 were the best for NUE, NUtE, DH, DM and SGD and cross P3 x P6 for NUtE and NUE. Both additive and dominance genetic components were significant for NUE, NUtE, SRI and SSI with greeter role for dominance. Narrow sense heritability was moderate for NUE, NUtE and SRI, but low for SSI.