Nitrogen use efficiency and low nitrogen tolerance in waxy corn

Abstract

Nitrogen use efficiency was evaluated in 27 genotypes of waxy corn to utilize as germplasm in breeding program for sustainable agriculture. Yield, yield components and agronomic traits analyzed similarity coefficient by Squared Euclidean and cluster analysis by Ward’s method could separate genotypes into 4 groups depending on ear size, plant height and flowering date. The large ear group gave yield higher than that of the small ear group and showed high value of low nitrogen tolerant index (LNTI) and nitrogen use efficiency (NUE). The genotypes, namely BW, PEK and SLKM showed high NUE, high yield in high nitrogen condition (HN) and low yield in low nitrogen condition (LN). WPP, BW and NSW genotypes showed high value of LNTI, and high yield in both low and high nitrogen conditions. The genotypes, namely THT and TNO gave low yield in both LN and HN; they showed low NUE and poorly responded to nitrogen fertilizer. The relationship among yield, LNTI and NUE indicated that the best genotype should be good LNTI and high NUE, and also gave high yield in both LN and HN. Selections of high yield genotype in HN and LN are suitable method for NUE improvement and low nitrogen tolerance genotype respectively.