Effects Of Phosphorus On Absorption Of Mineral Elements And Metabolism Of Carbon And Nitrogen In Pineapple Leaves

Phosphorus is an elements necessary for the growth and development of pineapples.At the present,effects of phosphate fertilizers or different phosphate fertilizers on the plant growth and development have been widely reported in crops,such as corn and rice,but the mechanism of phosphorus on the growth and development of pineapple is still unclear.This thesis used"golden pineapple"as the material,and designed 4 treatments,including K₂HPO₄treatment（T1）,Na H₂PO₄treatment（T2）,MS nutrient solution treatment（T3）and H₂O treatment（CK）,to study the effects of different phosphorus treatments on the mineral elements absorption and utilizations in pineapple.The main results obtained were as followings:1.Among different fertilization treatments,the SPAD value of pineapple leaves treated by K₂HPO₄（T1）was significantly higher than the other three treatments.2.Different fertilization treatments have no effects on the starch content of pineapple leaves.The soluble sugar content of leaves treated with K₂HPO₄（T1）,Na H₂PO₄（T2）and H₂O treatment（CK）significantly decreased,while the soluble sugar content of leaves treated with MS nutrient solution（T3）did not change significantly.3.Different fertilization treatments have an effect on the nitrogen metabolites of pineapple leaves.The soluble protein content of pineapple leaves treated with Na H₂PO₄（T2）,MS nutrient solution（T3）and H₂O（CK）decreased significantly.The amino acid content of leaf under each treatment decreased first and then increased.Six days after treatment,the amino acid content of pineapple leaves under each treatment increased significantly,and the amino acid content under the Na H₂PO₄treatment（T2）was significantly higher than that of the other treatments.4.Different fertilization treatments affected the content of nitrogen,phosphorus and potassium of pineapple leaves.After K₂HPO₄treatment（T1）and Na H₂PO₄treatment（T2）,the nitrogen and potassium content decreased;after treatment with K₂HPO₄treatment（T1）,Na H₂PO₄treatment（T2）and MS nutrient solution treatment（T3）,the phosphorus content of pineapple leaves significantly decreased;4 days after treatment,the phosphorus content of pineapple leaves under K₂HPO₄treatment（T1）,Na H₂PO₄treatment（T2）and MS nutrient solution treatment（T3）were significantly higher than that under H₂O treatment（CK）.5.Different fertilization treatments have effects on the content of boron and magnesium in pineapple leaves.The content of boron and magnesium in pineapple leaves after Na H₂PO₄treatment（T2）increased significantly,and the content of boron in pineapple leaves after MS nutrient solution treatment（T3）decreased.K₂HPO₄treatment（T1）had no significant effects on the contents of boron and magnesium in pineapple leaves.6.Different fertilization treatments affected the expression levels of phosphorus transporter genes in pineapple leaves.After K₂HPO₄treatment（T1）,the expression levels of AcPHT1,AcPHT2,AcPHT3,and AcPHT4 genes increased first and then decreased;after Na H₂PO₄treatment（T2）,the expression levels of AcPHT1,AcPHT2,AcPHT5 genes first increased and then decreased,and the expression of AcPHT3,AcPHT4 genes decreased gradually;the expression levels of AcPHT1,AcPHT2,AcPHT3,AcPHT4 AcPHT5 genes under MS nutrient solution treatment（T3）showed a downward trend.The expression levels of AcPHT1,AcPHT2,AcPHT3,AcPHT4and AcPHT5 genes under CK treatment were significantly higher than other treatments.Under K₂HPO₄treatment（T1）,Na H₂PO₄treatment（T2）and MS nutrient solution treatment（T3）,the expression level of AcPHT6 gene showed an increasing trend.7.Under K₂HPO₄treatment（T1）and Na H₂PO4 treatment（T2）,the expression level of Ac GOGAT1 gene increased first and then decreased.After K₂HPO₄treatment（T1）,the expression level of Ac GOGAT2 gene first decreased and then increased.After MS nutrient solution treatment（T3）,the expression levels of Ac GOGAT1 and Ac GOGAT2 genes showed a downward trend.The expression levels of Ac GOGAT1and Ac GOGAT2 genes under H₂O treatment（CK）were significantly higher than that under other treatments.