Study On The Relationship Between Nutrition Elements And Mastication In Citrus Fruit

Mastication is an important quality trait that affects taste and consumer preference of citrus fruits.The edible part of citrus fruits are segments,containing juice sacs and separated by segment membranes.In this experiment,segment membranes of citrus variety named,Citrus reticulata cv."Kinokuni",was used as research material to study dynamics of fruit mastication trait,concentrations of cell wall components and nutrient elements in segment membranes during fruit development;in addition effect of foliar fertilization and drought stress on cell wall components and nutrient elements of citrus segment membranes were also analyzed.We hope to explore a relationship between nutrient elements and mastication of citrus segment membranes.The results are as follows1.Differences in content of cell wall components of citrus segment membranes among different varieties during fruit ripening.Among three experimental varieties named Jinqiu,Nanfengmiju,and Nanfengmiguang;Jinqiu had the highest water-soluble pectin/pro-pectin(WSP/PP)ratio,at 0.42;while,lowest content of cellulose and hemicellulose were observed,at 24.57 g/kg and 26.78 g/kg,respectively.There was no difference in mastication between Nanfengmiju and Nanfengmiguang,both were at 0.2 But the cellulose and hemicellulose content of Nanfengmiguang were lower than that of Nanfengmiju,significantly reduced by 64.86 percent and 22.88 percent2.Differences in content of nutrient elements of citrus segment membranes among different varieties during fruit ripening.P,Fe,Mn,Cu and Zn content increased in the order Nanfengmiju>Nanfengmiguang>Jinqiushatangju.N,Mg,B content increased in the order Nanfengmiju>Jinqiushatangju>Nanfengmiguang.Ca content increased in the order Jinqiushatangju>Nanfengmiju>Nanfengmiguang K content increased in the order Jinqiushatangju>Nanfengmiju>Nanfengmiguang3.Changes of content of cell wall components of citrus segment membranes among different varieties during fruit development.As fruit mastication improved,WSP/PP ratio of Nanfengmiju,Nanfengmiguang and Ehima No.28 gradually increased During fruit development,the WSP/PP ratio of Nanfengmiju with worse mastication was consistently observed lower than that of Nanfengmiguang and Ehima No.28;while,its cellulose content was consistently higher than that of Nanfengmiguang and Ehima No.28,and its hemicellulose content was consistently higher than that of Ehima No.284.Changes of content of nutrient elements of citrus segment membranes among different varieties during fruit development.During 2018,from 102 to 190 days after flowering(DAF),content of macro and trace elements from segment membranes in Nanfengmiju showed a downward trend;in addition,content of Ca,Mg,Mn,B,and Zn in Nanfengmiguang also showed a downward trend,and content of N,P,K,and Fe first decreased and then increased,and content of Cu showed an upward trend From 104 to 147 DAF,content of N,P,K and Cu of segment membranes in Nanfengmiju were consistently higher than those in Nanfengmiguang,and were lower than those in Nanfengmiguang at 180 DAF.From 104 to 190 DAF,content of Ca,Mn,B,and Zn of segment membranes in Nanfengmiju were consistently higher than those in Nanfengmiguang,and content of Mg and Fe were consistently lower than those in Nanfengmiguang.During 2019,from 96 to 180 DAF,content of N,P,K,Ca,Mg,B,and Cu of segment membranes in Nanfengmiju showed a downward trend,and content of Fe,Mn and Zn first decreased and then increased;content of N,P and Cu of segment membranes in Ehima No.28 showed a downward trend,and content of Ca and Mn showed an upward trend,and content of K,Mg and Fe firstly decreased and then increased,and content of B and Zn first increased and then decreased.From 117 to 180 DAF,content of N from segment membranes in Nanfengmiju were lower than those in Ehima No.28;from 96 to 180 DAF,content of Mg and Fe in Nanfengmiju were higher than those in Ehima No.28.and content of K were lower than those in Ehima No.28;from 96 to 147 DAF,content of Ca and Mn of segment membranes in Nanfengmiju were higher than those in Ehima No.28,and lower than those in Ehima No.28 at 180 DAF;from 96 to 147 DAF,content of Zn in Nanfengmiju were lower than those in Ehima No.28,and higher than those in Ehima No.285.The effect of different foliar fertilizers application on fruit mastication trait and content of nutrient elements in Satsuma mandarin.Foliar spraying of Ca fertilizer reduced fruit mastication and content of P,K,Mg,and Mn;while,increased content of Ca,B and Zn were analyzed.Foliar application of Mg fertilizer reduced fruit mastication and mineral contents of Ca and Mg in segment membranes,and increased contents of Fe.Foliar spraying of Fe fertilizer on plant canopy reduced fruit mastication and K,Ca and Mg contents;while,increased contents of N,Fe,Mn,B,and Cu.6.The effect of drought stress on fruit mastication and content of nutrient elements in citrus.Drought stress reduced fruit mastication of Bendizao and mineral contents of K,Ca,B,Cu in its segment membranes,and increased contents of N,P,Mg,Fe,Mn,and Zn.Drought stress had no significant effect on fruit mastication of Nanfengmiju and Ca content;while,increased contents of N,P,K,Mg,Fe,Mn,B and Cu,reduced contents of Zn.In summary,as citrus fruits mature,the fruit mastication gradually improves.If the WSP/PP ratio of segment membranes is higher,fruit mastication is better.Moreover,if WSP/PP ratio is similar but cellulose and hemicellulose content is lower in segment membranes,fruit mastication is also known to be better.While,lower Ca and B mineral contents in segment membranes of citrus fruits noticed with better mastication trait.