Nitrogen Use Efficiency Components and Biomass Partitioning of Solanum Chacoense Across Growing Environments

Abstract

The robust root system of Solanum chacoense Bitt. (Chc) offers potential for improving nutrient use efficiency in potato breeding. This study investigated methods and traits associated with nitrogen uptake efficiency (NUpE) to facilitate the selection of superior Chc parents for developing improved potato varieties for two consecutive growing seasons. The objectives were to (1) determine correlations between phenotypic traits and nitrogen use efficiency (NUE) components in Chc genotypes, (2) evaluate the reliability of a greenhouse-based screening method for predicting field performance of NUE-related traits in Chc, and (3) identify Chc genotypes with superior NUpE for introgression into cultivated potato (S. tuberosum, Tbr) to improve NUE. Eight Chc genotypes and three Tbr cultivars (‘Atlantic’, ‘Elkton’, and ‘Harley Blackwell’) were grown in greenhouse and field environments under two nitrogen (N) application rates (84 and 168 kg ha⁻¹). Above-ground dry weight (AGDW), root and stolon dry weight (RSDW), tuber dry weight (TBDW), and total dry weight (TDW) were measured and correlated with N accumulation, NUpE, nitrogen utilization efficiency (NUtE), and NUE. AGDW and TDW in Chc were positively correlated with N accumulation, NUpE, and NUE in both environments over two years. Positive correlations for N accumulation and NUpE between greenhouse and field performance were observed for Chc genotypes in 2015, supporting the reliability of the greenhouse screening method. One Chc genotype (C-9) exhibited superior NUpE compared to the Tbr cultivar ‘Atlantic’ in both environments in the second season. These findings demonstrate the potential of using superior NUpE Chc parents for introgression into Tbr to develop potato cultivars with enhanced NUE.