Breeding for high-yield and nitrogen use efficiency in maize: Lessons from comparison between Chinese and US cultivars

High yield and efficient use of nitrogen is one of the major target for maize breeding worldwide. Both yield potential and nitrogen use efficiency (NUE) of maize is lower in China compared to that in the US. In this study, we analyzed the change of the plant traits related to high yield and NUE of maize cultivars registered and planted in China and US during the past 40 decades. Compared to the cultivar released in the US, Chinese cultivar are less tolerant to high planting density, higher ratio of ear height to plant height, low grain filling rate, more stay-green and longer growth period. We suggest an ideal plant architecture of maize for high yield and NUE. To achieve high yield and high NUE under intensive production conditions (medium and high nitrogen input, high density planting), an ideotype plant architecture is proposed which includes compact plant architecture, low ratio of ear height to plant height (around 0.36–0.38, close to the golden rate.), medium ear, small tassel, medium root size, one-layer brace root, half stay-green, efficient N remobilization, fast grain filling rate etc. The parameters can be utilized to guide future breeding.