Boron (B) toxicity, an important agricultural problem that limits crop productivity in different regions of the world, can occur in B-rich soils or in soils exposed to B-rich irrigation waters, fertilizers, sewage sludge, or fly ash. Boron toxicity can affect tomato (Solanum lycopersicum), which is one of the most widely grown vegetables worldwide, with more than 3 million ha under cultivation.
The typical symptoms shown by plants exposed to excess of B are reduced vigour, retarded development, leaf burn (chlorotic and necrotic patches in older leaves), and decreased number, size, and weight of fruits.
The incidence of boron (B) toxicity has risen in areas of intensive agriculture. The objective of this research was to study the how B toxicity (0.5 and 2 mM B) affects the time course of different indicators of abiotic stress in leaves of two tomato genotypes having different sensitivity to B toxicity (cv. Kosaco and cv. Josefina). Under the treatments of 0.5 and 2 mM B, the tomato plants showed a loss of biomass and foliar area. At the same time, in the leaves of both cultivars, the B concentration increased rapidly from the first day of the experiment. These results were more pronounced in the cv. Josefina, indicating greater sensitivity than in cv. Kosaco with respect to excessive B in the environment. The levels of O2 and anthocyanins presented a higher correlation coefficient (r > 0.9) than did the levels of B in the leaf, followed by other indicators of stress, such as GPX, chlorophyll b and proline (r > 0.8). Results of research indicate that these parameters could be used to evaluate the stress level as well as to develop models that could help prevent the damage inflicted by B toxicity in tomato plants.
Reference: Cervilla, Luis M., Blasco, Begoña, Rios, Juan J., Rosales, Miguel A., Sánchez-Rodríguez, Eva, Rubio-Wilhelmi, Maria M., Romero, Luis, Ruiz, Juan M., Parameters Symptomatic for Boron Toxicity in Leaves of Tomato Plants, Journal of Botany, 2012, 726206, 17 pages, 2012. https://doi.org/10.1155/2012/726206
