Nitrogen uptake and physiological use efficiency in Brazilian sugarcane (Saccharum £ spp.) cultivars: A gist of current understanding

Sugarcane (Saccharum spp.) cultivation in Brazil is more sustainable than in other producing countries because of better nitrogen (N) use efficiency (NUE). However, the physiological potential of Brazilian cultivars needs to be further explored in breeding programs by characterizing the efficiency of N acquisition (NUpE) and N utilization (NUtE). Among the most cultivated hybrids in Brazil, 18 cultivars developed since the 1970s were here evaluated upon greenhouse conditions exposed to two N levels (0.5 and 5 mM) provided as ammonium nitrate. Dry matter mass (roots, shoot, and total plant), N concentration (roots and shoot), and N accumulation (roots, shoot, and total) were determined and used to estimate NUpE and NUtE. Breeding after the 1990s appears to have favored NUtE in modern cultivars. The modern cultivars showed an average NUtE of 77.5 and 59.1 at 0.5 and 5 mM of N, respectively, while the eldest ones displayed lower NUtE values, 60.7 and 49.2 at each N level. However, NUpE was important for the response to N supplementation and the higher dry biomass production, and some old cultivars showed the best NUE associated with NUpE. N uptake was important for the performance of the eldest and more productive cultivars (e.g., SP81-3250 and RB72454). We observed that the improvement in NUE can be achieved by a more efficient uptake of N. This way, reintroducing the eldest cultivars to assist breeding programs and prioritizing the selection for better NUpE will probably improve NUE, favoring long-term environmental sustainability by reducing the need for nitrogen fertilization. (c) 2025 SAAB. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.