Uptake and utilization of different nitrogen forms in erect panicle japonica rice cultivar

Abstract

The response of rice to nitrogen (N) was compared between three rice cultivars and three N treatments: 1:0, 0:1, and 1:1 NH4+:NO3−. The three rice cultivars used were: Shennong1401 (SN1401, erect panicle rice cultivar) and Habataki and Sasanishiki (curved panicle rice cultivars). At the booting stage, higher gene expression and enzyme activity associated with N metabolism of rice in the including-NO3− solutions effected the secondary assimilation of N metabolism, and ultimately increased grain development. During the tillering stage, lower NO3− uptake rates and glutamine synthetase and NADH-dependent glutamate synthase activity in Habataki and Sasanishiki under the NO3− treatments resulted in lower effective panicle number per plant. However, no significant differences were observed in the grain yield per plant of SN1401 between NH4+ and NO3− treatments. Our results indicate that the erect panicle rice cultivar can grow better under the including-NO3− treatment.

Keywords

• erect panicle japonica
• hydroponics
• metabolic genes
• nitrogen uptake rate
• nitrogen use efficiency