中文摘要：

为研究盐胁迫下不同水氮对小桐子（Jatropha curcas）形态特征和水分利用的影响,采用3种施盐水平（S1：0 g,S2：3 g,S3：6 g）,3种供水水平（W1：12.7 mm,W2：25.4 mm,W3：38.1 mm）和2种施氮水平（N1：0 g,N2：0.4 g）进行盆栽试验。结果表明：随着施盐量的增多,小桐子胡伯尔值显著上升,而总干物质质量、壮苗指数和灌溉水利用效率均显著下降;随着灌水量的增加,小桐子灌溉水利用效率显著下降,而在S2和S3盐分胁迫下,小桐子总干物质质量和壮苗指数均在W2处理时达到最大值,胡伯尔值在W2处理时处于最小值;在每个灌水量与施盐量水平上,施氮处理（N2）的小桐子幼树总干物质质量、壮苗指数和灌溉水利用效率都比对照有显著增加,而胡伯尔值显著下降;在中盐胁迫（S2）条件下,与W3N2相比,W2N2的总干物质质量、壮苗指数和灌溉水利用效率分别显著增加了23.0%、16.6%和84.6%,胡伯尔值显著降低了21.1%,节约灌溉量达33.3%;在高盐胁迫（S3）条件下,与W3N2相比,W2N2的总干物质质量、壮苗指数和灌溉水利用效率分别增加了21.9%、5.6%和81.7%,胡伯尔值降低了7.3%,节约灌溉量达33.3%;在一定盐胁迫下,有利于小桐子生长、形态特征和灌溉水利用效率提高的最佳水氮耦合处理为W2N2处理。

英文摘要：

To study the effect of different water and nitrogen additions on Jatropha curcas mor- phological characteristics and water use efficiency under salt stress, a pot experiment was conduc- ted using three levels of salt application （SI： 0 g,S2：3 g, S3：6 g） , three levels of irrigation （ W1 ： 12.7 mm, W2 ： 25.4 mm, W3 ： 38.1 mm） and two levels of nitrogen supply （ N1 ： 0, N2 ： 0.4 g）. The results showed that with the increase of salt application, the Huber values of J. cur- cas increased significantly, while the total dry mass, seedling index and irrigation water use effi- ciency decreased significantly. With the increase of irrigation amount, the irrigation water use ef- ficiency decreased significantly. Under salt stress of S2 and S3 treatments, the maximum total dry matter weight and seedling index and the minimum Huber values were found in W2 treatment. On each level of irrigation and salt, the total dry mass of J. curcas saplings, seedling index and irri- gation water use efficiency under N treatment （N2） were significantly increased compared to the control, while the Huber value was significantly decreased. Under the intermediate salt stress （S2）, compared to W3N2 treatment, the total dry mass, seedling index, and irrigation water use efficiency under W2N2 treatment were respectively significantly increased by 23.0%, 16.6% and 84.6%, the Huber value was significantly decreased by 21.1%, and the irrigation amount was saved by 33.3%. Under the high salt stress condition （S3） , compared to W3N2 treatment, the total dry mass, seedling index, and irrization water use efficiency under W2N2 treatment were re-spectively increased by 21.9%, 5.6% and 81.7%, the Huber value was significantly decreased by 7.3%, and the irrigation amount was saved by 33.3%. In conclusion, under salt stress, W2N2 was the best treatment for facilitating the growth and morphological characteristics of J. curcas and improving irrigation water use efficiency.