氮磷鉀配比施肥對巨尾桉葉片及根系有機酸質量分數的影響1)

胡厚臻 李桃禎 李茹 侯文娟 陳鑫 滕維超 王凌暉

(廣西大學，南寧，530000)

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氮磷鉀配比施肥對巨尾桉葉片及根系有機酸質量分數的影響1)

胡厚臻 李桃禎 李茹 侯文娟 陳鑫 滕維超 王凌暉

(廣西大學，南寧，530000)

采用正交L9(34)試驗設計，研究不同氮(N)磷(P)鉀(K)配比施肥下巨尾桉GL9(Eucalyptusgrandis×E.urophylla)葉片、根系中有機酸種類及質量分數和根系有機酸酶活性。結果表明：葉片有機酸質量分數是根系的4.03～6.64倍；與對照(CK)相比，N3P2K1、N2P3K1的葉片有機酸質量分數分別比CK低7.44%和19.70%，其余配比均比CK高；而根系中N1P2K2、N1P3K3、N2P3K1的有機酸質量分數比CK低22.02%～31.07%，有機酸質量分數越低，表明巨尾桉的養分越均衡，肥料的元素配比越合理。葉片中蘋果酸、檸檬酸、乙酸占所有酸的85.21%～95.32%，根系中蘋果酸及檸檬酸占所有酸的54.99%～85.21%。相關分析表明，葉片與根系的總有機酸質量分數均與蘋果酸、檸檬酸顯著相關(p<0.05)，這兩種酸作為巨尾桉的優勢酸，可能是植物遭受養分脅迫的指示型酸；而有機酸酶PEPC、NAD-IDH酶活性與根系有機酸質量分數顯著相關(p<0.05)，PEPC是促進巨尾桉根系蘋果酸、檸檬酸積累的重要酶，NAD-IDH是與有機酸分解相關的酶。N素和P素是影響有機酸的主要因子，高氮低磷的配比加劇植物養分脅迫，產生更多的有機酸。綜合分析表明，中氮高磷低鉀的配比即N2P3K1遭受的養分脅迫最小，有機酸的質量分數最低，推薦最佳N、P2O5、K2O施肥量分別為15、9、6 g·株-1。

巨尾桉；氮磷鉀配比；有機酸；有機酸酶

A fertilization experiment was tested using an L9(34) orthogonal design and regression analysis to study the effects of the different combined fertilization of nitrogen (N), phosphorus (P) and potassium (K) on the characteristics of organic acids in roots and leaves ofEucalyptusgrandis×E.urophylla, and the activities of acid-metabolizing of roots. The content of organic acid in leaves was 4.03-6.64 times of that of the roots. Compared with CK, the organic acid contents in leaves of N3P2K1and N2P3K1were 19.70% and 7.44% lower than that of CK, and the rest ratio was higher than CK. The organic acid contents of N1P2K2, N1P3K3and N2P3K1in roots were 22.02%-31.07% lower than that of CK. The lower the organic acid content, the more balanced the nutrient, the more reasonable the element ratio of the fertilizer. The malic acid, citric acid and acetic acid accounted for 85.21%-95.32% of all acids in the leaves, Malic acid and citric acid accounted for 54.99% to 85.21% of all acids in root system. By correlation analysis, the total organic acid content of leaves and roots was significantly correlated with malic acid and citric acid (p<0.05), and those two acids, as the dominant acids of the eucalyptus, may be instruction type acid plant suffer from stress. Organic acid enzyme PEPC, NAD-IDH enzyme activity was associated with a significant root organic acid content (p<0.05), PEPC was to promote the root, malic acid, citric acid accumulation of key enzyme, NAD-IDH was related to the decomposition of organic acid enzymes. N and P is the main factor affecting the organic acid content, high nitrogen and low ratio of phosphorus increased plant nutrient stress and produce more organic acid. By comprehensive analysis, the ratio of high phosphorus and low potassium and potassium N2P3K1suffered the least nutrient stress, organic acid content was the lowest, recommended the best fertilization amount for N, P2O5and K2O were 15, 9 and 6 g per seedling.

植物在生長的過程中其不同的組織往往都會通過產生許多重要生理產物來調節自身的生命活動，其中有一種重要的物質就是有機酸，如蘋果酸、草酸、檸檬酸、丁二酸、酒石酸、乙酸、乳酸等[1]。植物組織中的有機酸不但參與了光合作用和呼吸作用，還參與了植物體內元素的吸收、運輸、積累等代謝過程，而且在應對養分豐缺、金屬脅迫等過程中扮演著重要的角色[2-3]。因此，可以根據植物體內有機酸種類和質量分數的變化，對植物所進行的生命活動和所處的環境進行一定的診斷。目前，對有機酸的研究已成為了植物生理學和植物營養學的一個熱點領域。……