Alharbi Khadiga, Haroun Samia A, Kazamel Amany M, Abbas Mohammed A, Ahmaida Safia M, AlKahtani Muneera, AlHusnain Latifa, Attia Kotb A, Abdelaal Khaled, Gamel Rasha M E
Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
Botany Department, Faculty of Science, Mansoura University, Mansoura 35516, Egypt.
Plants (Basel). 2022 Jul 20;11(14):1884. doi: 10.3390/plants11141884.
This experiment was conducted to investigate the effects of different nitrogen fertilizers (potassium nitrate and/or urea) on shoot parameters, relative growth rate, net assimilation rate, and nitrogen fractions, as well as to conduct transmission electron microscopy, of L. (cowpea) and L. (sunflower) leaves. A general improvement was recorded in the shoot parameters of the two plants, except for a decrease in the net assimilation rate by treatment of the two plants with 100% potassium nitrate plus 100% urea. The total nitrogen, insoluble protein, and total soluble nitrogen generally decreased in cowpea shoots from the treatments but increased in case of cowpea roots and sunflower shoots and roots. The examination of the ultrastructure changes in cowpea leaves confirmed the presence of two starch granules (in response to 100% potassium nitrate, 100% potassium nitrate plus 100% urea, and the control) and three granules (in response to 50% potassium nitrate plus 50% urea) and the disappearance of the starch granules (in response to 100% urea). Despite the starch granules not being detected in the leaves of the untreated sunflower, the treated plant showed the appearance of the highest number after treatment with 50% potassium nitrate plus 50% urea (2) and the most cell size with the 100% potassium nitrate treatment. Generally, our findings demonstrated that fertilization with 50% potassium nitrate plus 50% urea has the best influence on the growth parameters and nitrogen content in the two plants, but the magnitude of response was more pronounced in case of cowpea plants.
本实验旨在研究不同氮肥（硝酸钾和/或尿素）对豇豆和向日葵叶片的枝条参数、相对生长速率、净同化率和氮组分的影响，并进行透射电子显微镜观察。除了用100%硝酸钾加100%尿素处理使两种植物的净同化率下降外，两种植物的枝条参数总体上有所改善。处理后豇豆枝条中的总氮、不溶性蛋白质和总可溶性氮总体下降，但豇豆根、向日葵枝条和根中的这些指标有所增加。对豇豆叶片超微结构变化的检查证实，存在两个淀粉粒（对100%硝酸钾、100%硝酸钾加100%尿素和对照的反应）和三个淀粉粒（对50%硝酸钾加50%尿素的反应），以及淀粉粒的消失（对100%尿素的反应）。尽管在未处理的向日葵叶片中未检测到淀粉粒，但处理后的植株在用50%硝酸钾加50%尿素处理后淀粉粒数量最多（2个），在100%硝酸钾处理下细胞大小最大。总体而言，我们的研究结果表明，50%硝酸钾加50%尿素施肥对两种植物的生长参数和氮含量影响最佳，但豇豆植株的反应程度更明显。
