Evaluation of the changes of chlorophyll a fluorescence factors in the symbiosis of rosemary plants with mycorrhiza under traffic

The phenomenon of pollution emerges as an outcome of progress in industrialization and urban development. A substantial number of heavy metals, which possess the potential to impact both human well-being and the ecological surroundings, are found in traffic dust. Consequently, the discharge of heavy metals from automobiles emerges as a principal contributor to the contamination of metal substances in urban settings, owing to the heightened traffic volume. The presence of heavy metals can adversely influence photosystem reactions, disrupt the normal course of photosynthetic reactions, and ultimately lead to a decline in plant performance. Moreover, the establishment of mutualistic associations between mycorrhizal fungi and plants has the potential to further diminish pollution by inducing alterations and regulation of plant physiological mechanisms. This study was done to evaluate the effects of Mycorrhiza symbiosis on chlorophyll a fluorescence measurements in the Rosemary plant grown in high-traffic area of Shiraz city, Fars Province, Iran. The study was performed as a factororial and in the form of a randomized complete block design (RCBD) with three replicas and three factors. The first factor included Mycorrhiza symbiosis (control and inoculation); the second factor was traffic (control, ۱۲۰, ۳۰۰, ۶۰۰, ۹۵۰, ۱۲۰۰, ۱۸۰۰, ۲۴۰۰, ۳۰۰۰, ۳۶۰۰ and ۴۲۰۰ vehicles/h); and the third factor was covering the pot’s soil (control and cover). At the end of the experiment, some properties were studied such as by using the OJIP-test, various parameters like Area, Fo/Fm, Fv/Fm, N, Sm/t (Fm), ψo Po, ψo Eo, and ψo Po/ (۱- ψo Po). The results showed that inoculation led to increasing of Area, Fv/Fm, N, ψo Po, ψo Eo, and ψo Po/(۱- ψo Po) with ۵۷, ۱, ۷, ۲, ۲۵ and ۳۳% by compare to control, respectively. According to the results, it was found that the effects of inoculation, traffic and cover factors were significant at the ۱% statistical level on the studied traits. Based on the results of this experiment, it was found that plants inoculated with mycorrhizal fungi had a higher efficiency of the biochemical reaction of electron transfer compared to the control. Rosemary plants were located in the traffic paths of ۰ and ۱۲۰ vehicles/h and had a higher efficiency of the biochemical reaction of electron transfer. Plants that were in the path of ۳۰۰۰, ۳۶۰۰, and ۴۲۰۰ vehicles/h were significantly different in terms of the efficiency of the biochemical reaction of electron transfer with the control treatment (without traffic).

Keywords:

Chlorophyll a fluorescence , Photosynthesis , Traffic , Pollution , Chlorophyll a fluorescence , Photosynthesis , Traffic , Pollution