Shoot and root traits of summer maize hybrid varieties with higher grain yields and higher nitrogen use efficiency at low nitrogen application rates

Wennan Su; Muhammad Kamran; Jun Xie; Xiangping Meng; Qingfang Han; Tiening Liu; Juan Han

doi:10.7717/peerj.7294

Shoot and root traits of summer maize hybrid varieties with higher grain yields and higher nitrogen use efficiency at low nitrogen application rates

PeerJ. 2019 Jul 15:7:e7294. doi: 10.7717/peerj.7294. eCollection 2019.

Authors

Wennan Su^{1

2}, Muhammad Kamran², Jun Xie², Xiangping Meng^{1

2}, Qingfang Han^{1

2}, Tiening Liu^{1

2}, Juan Han^{1

2}

Affiliations

¹ Key Laboratory of Crop Physio-ecology and Tillage Science in North-western Loess Plateau, Ministry of Agriculture / College of Agronomy, Northwest A&F University, Yangling, Shaanxi, China.
² Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semi-arid Areas, Ministry of Education / Institute of Water Saving Agriculture in Arid Areas of China, Northwest A&F University, Yangling, China.

Abstract

Breeding high-yielding and nitrogen-efficient maize (Zea mays L.) hybrid varieties is a strategy that could simultaneously solve the problems of resource shortages and environmental pollution. We conducted a 2-year field study using four nitrogen application rates (0, 150, 225, and 300 kg N hm^-2) and two maize hybrid varieties (ZD958 and QS101) to understand the plant traits related to high grain yields and high nitrogen use efficiency (NUE). We found that ZD958 had a higher grain yield and nitrogen accumulation in the shoots at harvest as well as a higher NUE at lower nitrogen application rates (0 and 150 kg hm^-2) than QS101. The grain yields and NUE were almost identical for the two hybrid varieties at nitrogen application rates of 225 and 300 kg N hm^-2. Compared with QS101, ZD958 had higher above-ground and below-ground biomass amounts, a deeper root distribution, longer root length, root active absorption area, greater grain filling rate, and higher photosynthetic NUE than QS101 at lower nitrogen application rates. Our results showed that ZD958 can maintain a higher grain yield at lower nitrogen rates in a similar manner to N-efficient maize hybrid varieties. The selection of hybrids such as ZD958 with a deeper root distribution and higher photosynthetic NUE can increase the grain yield and NUE under low nitrogen conditions.

Keywords: Nitrogen use efficiency; Nitrogen-efficient hybrid variety; Photosynthetic nitrogen use efficiency; Root; Shoot.

Grants and funding

This study was supported by funding from the National High-Tech Research and Development Programs of China (“863 Program”) for the 12th Five-Year Plants (No. 2013AA102902), the Agro-scientific Research in the Public Interest under Grant (201303104), and the National Natural Science Foundation of China (No. 31601256). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.