Análisis del contenido de nitrógeno y parámetros composicionales en relación con la productividad en líneas avanzadas de Solanum tuberosum Grupo Phureja

Abstract

The creole potato (Solanum tuberosum Group Phureja) represents one of the most important native crops in Colombia, both for its nutritional value and for its high adaptability to Andean agroecological conditions and short vegetative cycle. In this context, genetic improvement through mutation induction, such as cobalt-60 irradiation, has enabled the selection of advanced lines (MV6) with agronomic and compositional potential. These lines allow the exploration of new dynamics in the efficient use of nutrients, such as nitrogen, a key macronutrient in the physiological processes of the crop and its impact on agronomic yield. This study evaluates the relationship between nitrogen content (organic and total), compositional parameters (moisture, ash, and protein), and agronomic parameters (productivity) in MV6 advanced lines of Solanum tuberosum Group Phureja, with the aim of establishing correlations between nitrogen accumulation and productive performance.The research was carried out at El Pino farm, located in Subachoque (Cundinamarca). Seven mutant clones (MV6-07, MV6-33, MV6-37, MV6-39, MV6-42, MV6-43, MV6-FB) were used, selected based on their productivity level (high, medium, and low), along with the Colombia variety as the non-irradiated control. Foliar samples were collected during the flowering stage, and tubers at harvest. Total and organic nitrogen content was determined using two methods: elemental CHN analysis and the Kjeldahl method. Moisture, ash content, and protein precipitation by isoelectric point were also evaluated. Data were analyzed using descriptive statistics, analysis of variance (ANOVA), and principal component analysis (PCA). Results showed that foliar tissue presented higher nitrogen concentrations (4.27–5.21% total and 0.34–0.96% organic) compared to tuber tissue (0.80–1.07% total and 0.10–0.16% organic), with statistically significant differences among genotypes (ANOVA, p<0.001). Proximal composition revealed characteristic values of moisture (85–88% in leaves vs. 72–81% in tubers) and ash content (12–17% in leaves vs. 3–4% in tubers), while protein precipitation exhibited marked variability between tissues (4–10% in leaves and 6–23% in tubers). In terms of productivity, clones MV6-37 (30.55 t/ha) and MV6-43 (28.66 t/ha) significantly outperformed the control COL (17.64 t/ha), although correlation analyses did not reveal strong relationships between nitrogen parameters and yield (R²<0.47). Exploratory PCA highlighted complex patterns in the interaction between chemical composition and agronomic performance, showing that MV6-07 was associated with high nitrogen and protein contents along with high productivity, whereas MV6-43 presented the highest productivity, reporting low nitrogen contents in leaves and moderate levels in tubers.These findings suggest that, beyond nitrogen content, other physiological and environmental factors influence yield, underscoring the need to adopt integrated approaches for the genetic improvement and agronomic management of creole potato in Colombia.