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在盆栽半控制试验中,采用两因素的随机区组设计,在3个土壤水分梯度(分别为80%、50%和30%的田间持水量(FC))下研究了施氮肥和不施氮肥处理麻疯树(Jatropha curcas)幼苗的光合特性。比较了不同水分和氮素供应条件下麻疯树幼苗的光合-光响应和CO2响应曲线、PSII的最大光化学效率(Fv/Fm)、氮含量和光合色素含量之间的差异。结果表明:1)施氮肥处理中,随着土壤水分含量的增加,叶片表观量子效率(AQY)、光补偿点、最大净光合速率、羧化效率、光呼吸速率、暗呼吸速率和叶片氮含量均呈现增加的趋势,而且均在80%FC下最高。2)不施氮肥处理中,随着土壤水分含量的增加,麻疯树各光合参数均与施氮肥处理呈现相反的变化趋势。3)在30%FC下,施氮肥处理和不施氮肥处理相比,氮含量显著增加,AQY、Fv/Fm、光合色素含量无显著的变化,其他各项指标均显著降低。这些结果表明,水氮耦合效应对麻疯树光合特性有显著影响,尤其是在80%FC下增施氮肥的效果最为明显。因此,在土壤氮素含量不高的情况下,麻疯树更适宜在较低的土壤水分下生长,土壤水分较高反而不利于麻疯树的光合作用;而如果增施氮肥,麻疯树在土壤水分含量较高时生长更好。
In a potted half-controlled trial, a two-factor randomized block design was used to study the effects of nitrogen and nitrogen fertilizers on three soil moisture gradients (80%, 50% and 30% field capacity (FC) Treatment of photosynthetic characteristics of Jatropha curcas seedlings. The photosynthetic - photochemical response and CO2 response curves, maximum photochemical efficiency (Fv / Fm), nitrogen content and photosynthetic pigment content of Jatropha curcas seedlings under different water and nitrogen supply were compared. The results showed that: 1) With the increase of soil water content, the apparent quantum yield (AQY), light compensation point, maximum net photosynthetic rate, carboxylation efficiency, photorespiration rate, dark respiration rate and leaf nitrogen Content showed an increasing trend, and are the highest at 80% FC. 2) In the non-nitrogen fertilizer application, with the increase of soil moisture content, the photosynthetic parameters of Jatropha curcas showed the opposite trend with the nitrogen fertilizer application. 3) At 30% FC, the nitrogen content increased significantly and the content of AQY, Fv / Fm and photosynthetic pigment had no significant change compared with the no nitrogen fertilizer treatment, while the other indexes decreased significantly. These results show that water and nitrogen coupling effects have significant effects on the photosynthetic characteristics of Jatropha curcas, especially at 80% FC. Therefore, in the case of soil nitrogen content is not high, Jatropha curcas is more suitable for growth in lower soil moisture, higher soil moisture is not conducive to photosynthesis of Jatropha curcas; and if the nitrogen application, Jatropha curcas Grow better when soil moisture is high.