Characterization of Potassium Chloride Stress on Philippine Vigna radiata Varieties in Temperature-stabilized Hydroponics Using Genetic Programming

Abstract

Chloride is an important micronutrient for crop plant life. Excess chloride dehydrates the plant system and accumulates salt-like residue in leaves causing them to undergo chlorosis and necrosis. Micronutrient stress through potassium chloride that is used as fertilizers to common and industrial farms was not yet comprehensively explored concerning mung beans. This study aims to characterize the effects of potassium chloride (KCl) fertilization on stems and roots of two Philippine mung bean (Vigna radiata L.) varieties which are the yellow and green mongo. A temperature-stabilized hydroponics setup was developed based on Peltier technology. Three KCl treatments were employed: 50 μM (control), 10 μM (deficient), and 100 μM (toxic or excess). Morphological assay confirmed that KCl deficient mung beans have longer root and shoot systems and higher number of spanning leaves. Lowering KCl concentration to 10 10 μM also increases the germination rate by 111.536% than the control. Light microscopy was performed and confirmed that there is thicker cortex, denser vascular cambium, broader xylem and phloem vessels, and larger parenchyma cells in KCl deficient seedlings. Only the green mung bean seedling variety exposed in excess KCl have formed trichomes within 14 days. Multigene genetic programming was applied to generate mathematical models of seedling architectural traits as functions of KCl concentration and cultivation period. It was found out that less than 0.05 mM, 0.9 mM 0.7 mM, 4 mM of KCl promotes root growth, shoot length, leaf expansion, and the number of spanning leaves, respectively. Overall, chloride deficiency improves mung bean growth.