雾培对网纹甜瓜根系生长和氮代谢的影响

Effects of Aeroponical Culture on Growth and Nitrogen Metabolism of Muskmelon Root

为了探讨雾培对网纹甜瓜生育的影响,以中蜜一号网纹甜瓜品种为试材,水培和基质培为对照,研究雾培对网纹甜瓜果实发育期根系生长和根系氮代谢的影响。结果表明:同水培和基质培相比,雾培显著促进网纹甜瓜植株根系生长和干物质积累,雾培根系伤流液流出速率、电导率和pH均最高。在果实发育初期雾培促进根系NO3--N和NH4+-N的暂时积累,但随着果实的发育,根系内氮含量逐渐下降。雾培根系的硝酸还原酶(NR)活性在花后0～30d低于水培和基质培,30d后迅速增加,花后40d时显著高于水培和基质培。谷氨酰胺合成酶(GS)、谷草转氨酶(GOT)和谷丙转氨酶(GPT)活性在果实发育期间均高于水培和基质培。蛋白质含量在花后0～20d内与水培和基质培差异不显著,30d时雾培根系蛋白质含量迅速增加,并显著高于水培和基质培。可见,雾培显著促进网纹甜瓜果实发育到成熟期间根系对氮的吸收和代谢。

Abstract In order to study the effect of aeroponics culture on growth and development of muskmelon root, this experiment was conducted with the muskmelon cuhivars of ＂First mark of Zhongmi＂ as ex perimental material and solution culture and matrix culture as the comparison. The effects ofaeropon- ics culture on root growth and root nitrogen metabolism of muskmelon were studied. The results were as follows： Compared to the control, aeroponics culture promoted the root growth and the dry matter accumulation of muskmelon. The flow rate of root xylem sap, conductivity and pH of aeroponics cul ture were the highest. The contents of NO3- N and NH4＋ -N were temporary accumulating in the aeroponics culture root during fruit development early. But with the development of fruit, the content of nitrogen in root was gradual decline. The activity of nitrate reductase （NR） of muskmelon root in aeroponics culture was lower than in the solution culture and matrix culture within 0--30 d flowering, and increased rapidly after flowering 30 d, and significantly higher than in the solution culture and ma- trix culture after 40 d flowering. The activity of glutamine synthetase （GS）, the activity of glutamic acid oxaloacetate transa-minase （GOT） and glutamic acid-pyruvic acid transa-minase （GPT） were higher in aeroponlcs cuhure than in solution culture and matrix culture during fruit development. The content of protein in the three planting methods was no significant differences within 0--20 d flower- ing. The protein content of muskmelon root cultured in aeroponics increased rapidly and significantly higher than in the solution culture and matrix culture after 30 d flowering. In conclusion, the aeropon- ics culture can significantly increase nitrogen uptake and metabolism in muskmelon root during the period of fruit development to mature.