摘要 : The use of <i>Jatropha curcas</i> oil as a source of biofuel has been well-explored. However, the physiological and growth studies of <i>J. curcas</i> have received considerably lesser attention. In this study, leaf gas exchange m... 展开 The use of <i>Jatropha curcas</i> oil as a source of biofuel has been well-explored. However, the physiological and growth studies of <i>J. curcas</i> have received considerably lesser attention. In this study, leaf gas exchange measurements and leaf nitrogen content were determined for four varieties of <i>J. curcas</i>, grown in the field or in pots. Based on stable carbon isotope analysis ( delta ¹³C) and gas-exchange studies, <i>J. curcas</i> is a C₃ sun plant and the range of leaf photosynthetic rates (or CO₂ assimilation rates, <i>P</i>_Nmax) were typically between 7 and 25 micro mol(CO₂) m^-2 s^-1 and light saturation generally occurred beyond 800 micro mol(quanta) m^-2 s^-1. Higher rates of leaf photosynthesis were generally obtained with the mature leaves. In addition, increased foliar <i>P</i>_Nmax were recorded in potted <i>J. curcas</i> variety Indiana with increasing nitrogen (N) nutrition levels. These plants also showed greater growth, increased leaf N content, higher maximum CO₂ assimilation capacity (<i>P</i>_NhighCO2) and chlorophyll (Chl) content, indicating the potential of optimizing the growth of <i>Jatropha</i> by varying fertilizer nutrient levels. A rapid assessment for leaf N using a nondestructive and portable Chl meter had been established for <i>J. curcas</i>. This approach will allow repeated sampling of the same plant over time and thus enable the monitoring of the appropriate levels of soil fertility to achieve good <i>Jatropha</i> plantation productivity. High N nutrition improved the overall plant oil yield by increasing the total number of fruits/seeds produced per plant, while not affecting the intrinsic seed oil content. 收起