磷对薄皮甜瓜生理代谢和产量形成影响的研究

为探究磷素对甜瓜生理代谢和产量形成的影响,以金妃甜瓜为材料,采用基质培养方法,研究不同浓度的磷素处理后,甜瓜果实横径、纵径、叶绿素含量、硝态氮含量、硝酸还原酶活性、可溶性糖含量、过氧化氢酶活性、超氧化物歧化酶活性、单果重和产量的变化规律。结果表明,在结果期,0.9~1.2mmol·L~(-1)范围内的磷用量对甜瓜果实生长促进作用最强,叶片中生理活性物质含量和保护性酶活性提高,进而提高甜瓜光合能力和生理代谢水平,增加果实横径和纵径,提高甜瓜产量。在授粉后30 d,0.9~1.2 mmol·L~(-1)范围内的磷用量显著提高了果实横径、果实纵径和产量,与0.3 mmol·L~(-1)(T1)磷用量相比,分别增加21.38%~26.00%、12.62%~34.09%和36.62%~46.72%;同时,在授粉后20~25 d,与T1相比,该范围内的磷用量显著提高了叶片叶绿素含量、硝态氮含量、可溶性糖含量以及硝酸还原酶、过氧化氢酶、超氧化物歧化酶活性,分别增加21.23%~29.99%、102.55%~128.59%、51.10%~56.51、24.91%~39.92%、7.46%~9.26%和13.23%~18.62%。而当磷用量低于0.6 mmol·L~(-1)(T2)或高于1.5 mmol·L~(-1)(T5)时,各项指标均显著下降。因此,0.9~1.2 mmol·L~(-1)范围内的磷素量施用可以提高甜瓜植株生理活性物质含量和保护性酶活性,促进甜瓜产量形成,但甜瓜植株的生理特性和产量指标在不同磷浓度下有显著差异。本研究结果为甜瓜生产合理施用磷肥提供了理论依据和实践指导。

The Research of Phosphorus on the Physiological Metabolism and Yield Formation in Muskmelon

To explore the physiological mechanism of phosphorus element on the physiological metabolism and yield formation in muskmelon,muskmelon (Jin-fei) was used as experimental material by substrate culture to reveal the change laws of fruit transverse diameter,fruit vertical diameter,chlorophyll content,nitrate nitrogen content,nitrate reductase activity,soluble sugar content,catalase activity and superoxide dismutase activity,single fruit weight and yield.The results showed that the dosage of phosphorus element at the range of 0.9 to 1.2 mmol· L-1 can best promote fruit growth of muskmelon through enhancing the leaf physiological active substance content and protective enzyme activity during fruit-bearing stage,which can improve the photosynthesis ability and physiological metabolism level,increase fruit transverse diameter and fruit vertical diameter,and promote the raising of muskmelon yield.Compared with 0.3 mmol· L-1 (T1) phosphorus content,the fruit diameter,the diameter of the fruit and the yield per hectare increased significantly at the range of 0.9 to 1.2 mmol·L-1 about 30d after pollination were 21.38％ to 26.00％,12.62％ to 34.09％,36.62％ to 46.72％,respectively.At the same time,compared with 0.3 mmol· L-1 (T1) phosphorus content,chlorophyll content,nitrate nitrogen content,soluble sugar content,nitrate reductase activity,catalase activity and superoxide dismutase activity increased significantly at the range of 0.9 to 1.2 mmol· L-1 during 20 to 25d after pollination,and were 21.23％ to 29.99％,102.55％ to 128.59％,51.10％ to 56.51％,24.91％ to 39.92％,7.46％ to 9.26％ and 13.23％ to 18.62％,respectively.When phosphorus dosage was less than 0.6 mmol· L-1 (T2) or higher than 1.5 mmol·L-1 (T5),all indexes decreased significantly.Therefore,phosphorus element at the range of 0.9 to 1.2 mmol·L-1 can improve physiological active substance content and protective enzyme activity of the melon plants,and can promote the yield formation of muskmelon.However,the physiological characteristics and yield index of muskmelon during the fruit-bearing stage were different under different phosphorus concentrations.The results provided a theoretical basis and practical guidance for the proper application of phosphorus fertilizer in muskmelon production.