Photosynthetic capacity and water use efficiency in Ricinus communis (L.) under drought stress in semi-humid and semi-arid areas

Abstract

Castor bean is one of the crops with potential to provide raw material for production of oils for biodiesel. This species possess adaptive mechanisms for maintaining the water status when subjected to drought stress. A better understanding these mechanisms under field conditions can unravel the survival strategies used by this species. This study aimed to compare the physiological adaptations of Ricinus communis (L.) in two regions with different climates, the semi-arid and semi-humid subject to water stress. The plants showed greater vapor pressure deficit during the driest hours of the day, which contributed to higher values of the leaf temperature and leaf transpiration, however, the VPD (leaf-air) had the greatest effect on plants in the semi-arid region. In both regions, between 12:00 p.m. and 2:00 p.m., the plants presented reduction in the rates of photosynthesis and intracellular CO 2 concentration in response to stomatal closure. During the dry season in the semi-arid region, photoinhibition occurred in the leaves of castor bean between 12:00 p.m. and 2:00 p.m. These results suggest that castor bean plants possess compensatory mechanisms for drought tolerance, such as: higher stomatal control and maintenance of photosynthetic capacity, allowing the plant to survive well in soil with low water availability.

Gas exchange characteristics and their influencing factors for halophytic plant communities on west coast of Bohai Sea

“…The photosynthetic capacity was determined by the surroundings and influenced by genetic factors. To some extent, the photosynthetic capacity and water use efficiency of the plants are determined by their intrinsic factors under specific environmental conditions [42]. In this research, the Fratios of species are higher than the site, and their interaction also confirmed the inference in Table 2.…”

Water Use Efficiency of Acacia seyal (Del.) in extreme arid environment prevails in South-Western Desert, Egypt

“…Online ISSN: 2735-4237, Print ISSN: 2735. http://aujes.aswu.edu.eg/ maintain photosynthetic activities (Roel et al, 2011;Broeckx et al, 2014;Dos Santos et al, 2017). Fig.…”

Photosynthetic performance in Eucalyptus clones cultivated in saline soil

“…Besides that, the Eucalyptus clones submitted to salt stress showed an inverse correlation between VPD (leaf-air) with stomatal conductance and transpiration. In that the increase of the VPD (leaf-air) possibly influenced in the stomatal closure and the reduction of the transpiration probably due to the low water availability present in the saline soil (Pinheiro et al, 2008;Santos et al, 2017).…”

“…In the most C3 species, high values of VPD (leaf-air) are related to stomatal closure as well as high values of VPD (leaf-air) reducing transpiration, especially when developed in environments with low soil water availability (Santos et al, 2017). The positive correlation between stomatal conductance, transpiration, and photosynthesis that was found among the clones in this study confirms that the plants were under water stress in response to high soil salinity, which led to the partial stomata closure, decreased transpiration and led to sharp decline in photosynthetic rates.…”