[Effects of applying calcium on peanut physiological characteristics, its yield and kernel quality under cadmium...

Taking high-oil peanut cultivar Yuhua15 and high-protein peanut cultivar XB023 as test materials, a pot experiment was conducted in both 2009 and 2010 to study the effects of applying different concentration calcium (Ca) on the vegetative growth, leaf chlorophyll content, photosynthetic rate, and protective enzyme activities, as well as the yield and kernel quality of the cultivars under cadmium (Cd) stress. Applying Ca alleviated the inhibitory effects of Cd on the height growth of peanut main stem and the length growth of the branches, resulting in the increase of plant dry mass, and mitigated the Cd damage on peanut leaf, manifesting in the increase of leaf chlorophyll content, photosynthetic rate, superoxide dismutase (SOD), peroxidase (POD), and catlase (CAT) activities, and soluble protein content, and the decrease of leaf malondialdeyde (MDA) content. Under the application of Ca, both the pod yield and the kernel yield increased, mainly because of the increase of pod number per plant and of the kernel number per pod. Applying Ca also promoted the transformation of soluble sugar into fat and protein in peanut kernel, increased the kernel fat and protein contents, and improved the kernel quality under Cd stress. Ca application decreased the kernel Cd content of the cultivars, with better effect on Yuhua15 than on XB023.