Document Type : Research Paper

Authors

• Ali Salehi Sardoei ¹
• mehdi Sharifani ²
• mostafa khoshhal sarmast ³
• mahmoud Ghasemnezhad ⁴

¹ Horticulture Department, Faculty of Plant Production, University of Agriculture and Natural Resources, Gorgan, Iran

² Associate Professor, of Horticulture, Faculty of Plant Production, Gorgan University of Agriculture and Natural Resources, Gorgan, Iran

³ Assistant Professor, of Horticulture, Faculty of Plant Production, Gorgan University of Agriculture and Natural Resources, Gorgan, Iran

⁴ Professor of Horticulture, Faculty of Agriculture, University of Guilan, Guilan, Iran

Abstract

Citrus sinensis cv Thomson Navel and Citrus limon cv Lisbon are known as relatively resistant and cold-sensitive garden products. Thus, in the present study attempts are made to investigate the vulnerability of Thomson oranges and Lisbon lemons to cold stress under controlled environmental conditions compared to treatment temperatures (4, -4 and -8 °C). This factorial experiment was conducted according to a completely randomized design. The ANOVA results showed that the temperature/cultivar interaction can significantly affect some traits such as lipid peroxidation, superoxide dismutase, ascorbate peroxidase, total flavonoids, ion leakage, chlorophyll a, carotenoids, total chlorophyll and LT50 (P> 0.001). However, the catalase/chlorophyll b interaction was found to be significant at p= 5%. The highest levels of ion leakage (59.65%), lipid peroxidation reaction (0.77 µg g−1 FW MDA) in lemon and catalase and superoxide dismutase (33.43 µmol•g−1 FW and 160.3.3 μmol g −1FW min respectively) in orange was recorded at -8 °C. In contrast, the highest levels of ascorbate peroxidase (39.7 µg g−1 FW) was recorded in lemon and total flavonoids (32.48 mg g−1 FW of catechin) was recorded in oranges at 4 °C. in the present study, different reactions were also observed at different temperatures. Oranges showed higher resistance to cold compared to lemons. As for the measured traits, however, oranges were mostly ranked higher than lemons. Exposure of genotypes to cold stress led to an increase in malondialdehyde.

Keywords

• Citrus genotype
• Chlorophyll
• Free radical
• Lipid peroxidation

Main Subjects

• Physiology