ObjectivesResponse of photosynthetic characteristics and chloroplast ultrastructure of different Fe sensitivity citrus rootstocks to different iron (Fe) treatments was studied.
MethodsA hydroponic experiment was carried out with –Fe (0 μmol/L) and +Fe (37.3 μmol/L), and citrange and trifoliate orange rootstocks were selected as research materials. The contents of Fe, photosynthetic pigment and carbohydrates and chloroplast ultrastructure of samples were analyzed.
ResultsThe results showed that Fe deficiency significantly decreased the contents and accumulation of Fe, photosynthetic pigment contents in both rootstocks, and the photosynthetic pigment content in citrange rootstock was decreased in a larger extent. The iron deficiency significantly decreased carbohydrates contents in leaves of trifoliate orange, and the contents of total soluble sugar and glucose in leaves of citrange were significantly increased under Fe-deficiency, however, the contents of fructose and starch in leaves of citrange were significantly decreased with no Fe supply. Lamellae structure in chloroplast became fuzzy, and the numbers of plastoglobulus were increased without the Fe application. Compared with the Fe-sufficiency treatment, the chloroplast length and the chloroplast thickness of trifoliate were decreased by 22.1% and 26.4%, and those of the citrange orange were decreased by 55.1% and 40.4%.
ConclusionsThe content and accumulation of iron, the content of photosynthetic pigment and the ultrastructure of chloroplast of citrange rootstocks were more sensitive to Fe deficiency.
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