Relationship of Nitrogen Use Efficiency with the Activities of Enzymes Involved in Nitrogen Uptake and Assimilation of Finger Millet Genotypes Grown under Different Nitrogen Inputs

Abstract

Nitrogen responsiveness of three-finger millet genotypes (differing in their seed coat colour) PRM-1 (brown), PRM-701 (golden), and PRM-801 (white) grown under different nitrogen doses was determined by analyzing the growth, yield parameters and activities of nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase; GOGAT, and glutamate dehydrogenase (GDH) at different developmental stages. High nitrogen use efficiency and nitrogen utilization efficiency were observed in PRM-1 genotype, whereas high nitrogen uptake efficiency was observed in PRM-801 genotype. At grain filling nitrogen uptake efficiency in PRM-1 negatively correlated with NR, GS, GOGAT activities whereas it was positively correlated in PRM-701 and PRM-801, however, GDH showed a negative correlation. Growth and yield parameters indicated that PRM-1 responds well at high nitrogen conditions while PRM-701 and PRM-801 respond well at normal and low nitrogen conditions respectively. The study indicates that PRM-1 is high nitrogen responsive and has high nitrogen use efficiency, whereas golden PRM-701 and white PRM-801 are low nitrogen responsive genotypes and have low nitrogen use efficiency. However, the crude grain protein content was higher in PRM-801 genotype followed by PRM-701 and PRM-1, indicating negative correlation of nitrogen use efficiency with source to sink relationship in terms of seed protein content.

A Review of Nutrient Management Studies Involving Finger Millet in the Semi-Arid Tropics of Asia and Africa

“…Genotypic variability among different finger millet cultivars has been reported for responsiveness to N and P [54]. Gupta et al [6] ) under pot conditions. They found that there was genotypic variability among the finger millet genotypes' responses to different N inputs, wherein some varieties were highly responsive to N. Therefore, identification of genotypes with higher N use efficiency and N utilization efficiency especially under low available soil N levels will benefit farmers who cannot afford N fertilizer or who do not have access to N fertilizer sources.…”

“…Finger millet responds well to N application [6,22,50], since many of the soils in the semi-arid regions of Asia are deficient in N [25]. Studies concerning N management in finger millet are mainly focused on the amount of N applied, timing of application, and varietal responses to N. Rao et al [51] reported increases in yield and grain protein content in finger millet due to N fertilizer application rates of up to 40 kg N ha −1 in Andhra Pradesh, India.…”

Evaluation of Sensor-Based Nitrogen Rates and Sources in Wheat

“…However, excessive N fertilization in cultivated land has profound environmental impacts such as nitrate leaching, soil denitrification, ammonia volatilization, and nitrous oxide emissions, which contaminate water and air and aggravate the climate change [4,5]. While N losses cannot be avoided completely, they can be substantially reduced with sustainable agricultural practice such as adjusting N rate, timing and using the most appropriate fertilizer source, and adopting precision nutrient management technologies [6].…”

Energetic and Economics of Different Tillage Methods and Conservation Farming in Finger Millet

“…Dida et al, (2008) reported that the crop was domesticated in the highlands of Ethiopia and Uganda 5000 years ago, but reached India 3000 years ago. Today, the crop is ranked fourth globally in importance among the millets, after sorghum, pearl millet, and foxtail millet (Gupta et al, 2012). In India, finger millet is primarily grown in the states of Karnataka, Andhra Pradesh, Odisha, and Tamil Nadu (Dass et al, 2013).…”