TY - JOUR AU - Pérez-Molina, Junior Pastor AU - Castro Lara, Raquel AU - Portuguez Brenes, Ian AU - Araya Trejos, Valerie AU - Quesada Traña, Andrey PY - 2020/03/27 Y2 - 2024/03/29 TI - Chlorophyll fluorescence and biomass partitioning within light and nitrogen deficiency: An example of the use of the R programming language for teaching JF - UNED Research Journal JA - URJ VL - 12 IS - 1 SE - Articles DO - 10.22458/urj.v12i1.2629 UR - https://revistas.uned.ac.cr/index.php/cuadernos/article/view/2629 SP - e2629 AB - <p><strong>Introduction:</strong> Chlorophyll Fluorescence (<em>Fv/Fm</em>) detects damage in photosystem II (PSII) in plants exposed to stress (biotic and/or abiotic). <strong>Objective:</strong> In this context, <em>Fv/Fm</em> for the diagnosis of the effect of <em>N</em> deficiency and light in tomato plants (<em>Solanum lycopersicum</em>) was evaluated. <strong>Methods: </strong>We used the software R to analyze data from an experiment consisted of two light treatments (<em>high</em> and <em>low</em>) and two Hoagland nutritive solutions (<em>N</em> deficiency: <em>(-)N</em>; and complete solution: <em>C</em>). Twenty tomato plants within the two light treatments, with two nutrient levels (<em>(-)N</em> and <em>C</em>) were used. For four weeks, weekly measurements for height (<em>H</em>), leaf number (<em>NL</em>), and <em>Fv/Fm</em> were made. On the fourth week, the dry mass partitioning (root: <em>RMR</em>; stem: <em>SMR</em>; and leaves: <em>LMR</em>) and chlorophyll concentration (<em>a</em>, <em>b</em>, <em>a/b</em>, and <em>total</em>) was measured. <strong>Results:</strong> We found statistically significant differences between treatments for <em>H</em>, <em>NL</em> and <em>Fv/Fm</em> (<em>KW</em>&gt; 14,5, g.l.= 3,76, P&lt;0,01), but no differences for chlorophyll concentration (<em>F</em>&lt;2,2; g.l.=1, 16, P&gt;0,05). In both light conditions it was higher <em>LMR</em> in <em>C </em>treatment, but with lower <em>RMR</em> compared to <em>(-)N</em>. Statistically significant correlations (% <em>Spearman</em>, P&lt;0,05) between <em>Fv/Fm</em> and <em>LMR</em>, <em>RMR</em>, and <em>SMR</em> (-76%, 69%, and 37%, respectively) were found. <strong>Conclusion:</strong> Overall, we can emphasize that the <em>Fv/Fm</em> is a sensitive variable to the stress caused by nitrogen and light deficiency, whose progress of stress time-course can assess. Finally, <em>Fv/Fm</em> proved to be an indicator of the dry mass partition of stress induced by <em>N</em> deficiency and could be implemented as diagnostic in breeding programs.</p><p><strong>&nbsp;</strong></p><p><strong>&nbsp;</strong></p> ER -