Calcium sulfate ameliorates the effect of aluminum toxicity differentially in genotypes of highbush blueberry (Vaccinium corymbosum L.)

Abstract

The effect of gypsum (CaSO 4 ) amendment in the reduction of Al phytotoxicity of blueberry cultivars differing in Al resistance (Legacy and Brigitta, Al-resistant and Bluegold, Al-sensitive) was studied in a Hoagland's nutrient solution under acidic conditions for 2 weeks. Treatments were: Control (Hoagland solution), 2.5 mM CaSO 4 , 5 mM CaSO 4 , 100 µM Al (AlCl 3 ), 100 µM Al + 2.5 mM CaSO 4 , 100 µM Al + 5 mM CaSO 4 . Physiological, biochemical and chemical features of leaves and roots were determined to establish the amendment efficiency in the reduction of Al toxicity in these cultivars. Results showed that under Al toxicity the three investigated cultivars accumulated high Al concentrations in leaves and roots. These concentrations decreased with CaSO 4 application. Statistically significant interactions among Al in leaves but not in roots (p=0.719) and cultivars (p<0.001), were found. The lowest Ca concentration was found in the most Al-sensitive cultivar (Bluegold) and the highest in the more Al-resistant cultivars (Legacy and Brigitta). Among the underlying processes affected by Al stress in these blueberry cultivars the most evident changes were exhibited by the Al-sensitive cultivar Bluegold, where the photosynthetic performance decreased showing a slight recovery in presence of gypsum amendment at the end of experiment. Instead, the more Al-resistant cultivar (Legacy) did not change its photosynthetic parameters in presence of the gypsum amendments during the treatment, whereas in Brigitta, only a slight recovery at the end of treatment was evidenced by the gypsum application. Thus, in relation to these parameters the gypsum amendment was efficient in complete recovery from the toxic Al effect in the Al-resistant cultivar Brigitta and a slight recovery of the toxic Al effect in the Al-sensitive cultivar Bluegold. Nonetheless, this amendment is a good alternative to ameliorate Al toxicity in Al-sensitive cultivars and additionally provides a good source of Ca and S.

Photosynthetic and Antioxidant Performance Are Differentially Affected by Short-Term Nitrogen Supply in Highbush Blueberry Cultivars at the Short-Term

“…Assimilation of CO 2 was measured at the end of experiment between 9 and 10 a.m. in intact leaves belonging to the second node using a portable photosynthesis system (LI-6400, LI-COR Bioscience, Inc., Lincoln, Nebraska, US & Canada) as described by Reyes-Díaz et al (2011).…”

Comparative study of methodologies to determine the antioxidant capacity of Al-toxified blueberry amended with calcium sulfate

“…Highbush blueberry is commonly cultivated in soils with a pH between 4.0 and 5.5; however, it is well known that in acidic soils, high amounts of toxic Al 3+ can be released into the soil solution, damaging the roots and retarding shoot growth (Reyes-Díaz et al, 2011). This cation may be associated with ROS production, which induces oxidative stress in cell organelles (Yamamoto et al, 2002;Ma et al, 2007).…”

“…For plant species well adapted to acidity, such as blueberry, CaSO 4 represents an optimal alternative because it does not alter soil pH (Meriño-Gergichevich et al, 2010;Reyes-Díaz et al, 2011). The effect of CaSO 4 on biochemical features such as the antioxidant capacity of blueberry has been poorly studied.…”

“…The effect of CaSO 4 on biochemical features such as the antioxidant capacity of blueberry has been poorly studied. Reyes-Díaz et al, (2011) as an oxidant (Benzie and Strain, 1996); ii) 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), where ABTS ·+ is the radical cation used for the assay (Re et al, 1999); and iii) The Folin-Ciocalteu method or total phenolics assay (Singleton and Rossi, 1965).…”

Aluminum buffering in acid soil under mineral gypsum application

“…Gypsum application in the soil can promote modifications in these different Al compartments (Takahashi et al, 2006;Li et al, 2010;Álvarez et al, 2012). This is important because plants have different tolerance to the presence of exchangeable Al in the soil (Reyes-Díaz et al, 2011). Decrease in soil Al contents occurs due to the formation of Al-hydroxides and Alsulfate minerals of low crystallinity resulting from the gypsum application (Takahashi et al, 2006).…”