Mo Xiaorong, Chen Chuanwu, Riaz Muhammad, Moussa Mohamed G, Chen Xiangling, Wu Songwei, Tan Qiling, Sun Xuecheng, Zhao Xiaohu, Shi Libiao, Hu Chengxiao
Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China.
College of Resources and Environment, Beibu Gulf University, Qinzhou 535011, China.
Plants (Basel). 2022 Nov 1;11(21):2943. doi: 10.3390/plants11212943.
The effects of the increased soil copper (Cu) on fruit quality due to the overuse of Cu agents have been a hot social issue. Seven representative citrus orchards in Guangxi province, China, were investigated to explore the fruit quality characteristics under different soil Cu levels and the relationship between soil-tree Cu and fruit quality. These results showed that pericarp color a value, titratable acid (TA), and vitamin C (Vc) were higher by 90.0, 166.6, and 22.4% in high Cu orchards and by 50.5, 204.2, and 55.3% in excess Cu orchards, compared with optimum Cu orchards. However, the ratio of total soluble solids (TSS)/TA was lower by 68.7% in high Cu orchards and by 61.6% in excess Cu orchards. With the increase of soil Cu concentrations, pericarp color a value and Vc were improved, TA with a trend of rising first then falling, and TSS/TA with a trend of falling first then rising were recorded. As fruit Cu increased, pericarp color a value and TSS reduced and as leaf Cu increased, TSS/TA decreased while Vc was improved. Moreover, a rise in soil Cu enhanced leaf Cu accumulation, and a rise in leaf Cu improved fruit Cu accumulation. Fruit Cu accumulation reduced fruit quality by direct effects, leaf Cu improved fruit quality by direct and indirect effects. Soil Cu affected fruit quality by indirect effects by regulating leaf Cu and fruit Cu. Therefore, reasonable regulation and control of soil Cu concentrations can effectively increase pericarp color, sugar, and acid accumulation in citrus fruit.
由于铜制剂的过度使用，土壤铜（Cu）含量增加对果实品质的影响已成为一个社会热点问题。对中国广西的7个代表性柑橘果园进行了调查，以探究不同土壤铜水平下的果实品质特征以及土壤-树体铜与果实品质之间的关系。这些结果表明，与最佳铜果园相比，高铜果园的果皮颜色a值、可滴定酸（TA）和维生素C（Vc）分别高出90.0%、166.6%和22.4%，而铜过量果园则分别高出50.5%、204.2%和55.3%。然而，高铜果园的总可溶性固形物（TSS）/TA比值降低了68.7%，铜过量果园降低了61.6%。随着土壤铜浓度的增加，果皮颜色a值和Vc有所改善，TA呈先上升后下降趋势，TSS/TA呈先下降后上升趋势。随着果实铜含量增加，果皮颜色a值和TSS降低，随着叶片铜含量增加，TSS/TA降低而Vc改善。此外，土壤铜含量的增加增强了叶片铜的积累，叶片铜含量的增加改善了果实铜的积累。果实铜积累通过直接作用降低果实品质，叶片铜通过直接和间接作用改善果实品质。土壤铜通过调节叶片铜和果实铜间接影响果实品质。因此，合理调控土壤铜浓度可有效增加柑橘果实的果皮颜色、糖分和酸积累。
