Alternative screening criteria for selecting nitrogen-use efficient genotypes of maize [electronic resource].
معايير التصفية لإنتخاب تراكيب وراثية من الذرة الشامية ذات كفاءة استخدام نيتروجين عالية.
- p.27-40.
Includes references.
Developing nitrogen-use efficient (NUE) genotypes of maize (Zea mays L.) could reduce crop N fertilizer requirement However, determining N uptake and utilization efficiencies can he costly and time consuming. The main objective of this investigation was to evaluate alternative criteria for determining N-use efficiency traits in maize genotypes in an attempt to save time and reduce expenses in selection for N-use efficiency. The results .showed that under low-N, genetic correlation coefficient (rg) was .significant, positive and very high in magnitude for economic nitrogen use efficiency (NUEg) vs. grain dry matter (GDM) (rg = 1.00), biological nitrogen efficiency (NUE,) vs. total dry matter (TDM) (rg = 1.00), nitrogen uptake efficiency (NUPE) va. each ofGDM (rg 0= 1.00) and TDM (rg = 1.00). Furthermore, the genetic correlation between plant nitrogen utilization efficiency (NUTEJ and each of GDM and harvest index (HI) under low-N was positive and very strong (rg = 1.00). A positive and significant rg value was found between HI and nitrogen translocation efficiency (NTRE) (0.82). Therefore, grain dry matter, total dry matter and harvest index could be considered as good alternative screening criteria for NUE", NUPE, and NTRE (or NUTEJ traits respectively. These result indicate that grain nitrogen content (GN) could also be used as an alternative selective criterion for measuring most nitrogen efficiency traits, especially under low-N conditions. under low-N, broad-sense heritability (h2b) of the two alternative screening criteria: . .:.''tl I(88.84 %) and HI (77.65 %) was much higher than that of NUPE (30.44 %) and NTRE (50.82 %) or NUTEp (6.42 %) and that of GDM (80.60 %) was comparable to that of NUEc (80.61 %). Results suggest that future research should focus on the incorporation of some secondary traits such as GN and GDM traits in the selection programs along with NUEc trait in order to maximize the genetic gain from selection for improving NUE".
Summary in Arabic.
Corn--Genetics. Corn--Breeding Corn--Selection. nutrient use efficiency.