Iranian Journal of Plant Physiology
Volume:14 Issue: 1, Autumn 2024

This study aimed to investigate the changes in thermal indices of various clover genotypes under cold stress. A field experiment was conducted to evaluate the effect of different planting dates (14 Sep., 28 Sep., and 8 Oct.) and clover genotypes (late-maturity Persian clover, mid-maturity Persian clover, early-maturity Persian clover, berseem clover, red clover, and crimson clover). The results showed that delaying the planting date from September 14 to October 8 caused a significant decrease in growing degree-day (GDD), photothermal index (PTI), and heat use efficiency (HUE) in all studied genotypes. Early-maturity Persian clover and crimson clover had the lowest thermal requirements, while red clover had the highest GDD in all the investigated planting dates. During the first cut, the early-maturity Persian clover demonstrated the highest HUE (4.09 kg ha-1 °C days), followed by crimson clover. In contrast, red clover recorded the lowest HUE (1.43 kg ha-1°C days) on the last planting date. Early-maturity Persian clover and crimson clover may be preferred for forage production under cold stress due to their higher HUE values. The highest dry matter yield of the first cut (6300 kg ha-1) was obtained on the first planting date and by mid-maturity Persian clover, while the lowest yield (2429 kg ha-1) was obtained on the last planting date and by red clover. Overall, delayed planting dates resulted in accelerated development and decreased thermal requirements in clover species. The early-maturity genotypes were found to be more suitable for forage production under environmental stresses such as water shortages.

Peppermint infusion is a popular herbal drink with a number of benefits on cardiovascular, digestive, respiratory systems. Recent researches demonstrated that ultraviolet radiation can have an effect on peppermint essential oil. Considering the actual increasing of UV-B in the sun radiation, it’s important to estimate real conditions and which economic consequences it may have. Mentha x piperita L. plants grown in field were irradiated for one hour with UV-B light (310 nm, 3.8 Wm-2), in the middle of the day, for two days. The five upper leaves were collected at 4, 20, 24, 28, 44 and 48 h after the first treatment. Plants of M. x piperita cultivated under the same circumstances without the treatment were utilized as the control at each time point. Results showed that the biosynthesis of peppermint essential oil is modulated by UV-B irradiation, but the plants have also their mechanisms of protection from UV by increasing the ROS-scavenging enzymes activity. Also, expression of some involved genes in pathway modified in the presence of UV and showed regulating effect in essential oil biosynthesis significantly. Another confirmation of the protection from UV-B light was the stable concentration of photosynthetic pigments. Analysis of ROS-scavenging enzymes suggests that plants had an oxidative stress. In conclusion, this work is a one step to understand the regulation of terpenoid biosynthesis and the effects of UV-B radiation on it. Complex analysis of whole plant’ response will be helpful for this aim.

Sunburn is one of the significant problems in pomegranate growing, which reduces fruit yield and quality. This study was conducted to evaluate the impact of the application of antiperspirants on the quality and biochemical properties of pomegranate fruits. The experiment was carried out as a completely randomized design with nine treatments and three replications. Treatments include 2% solution talc (T), zinc oxide (ZnO), kaolin (K), zinc oxide+talc (ZnT), talc+kaolin (TK), zinc oxide+kaolin (ZnT), zinc oxide+talc+kaolin (ZnTK), shading with 50% light passing and control (sprayed with water). The highest edible fruit was measured in the ZnO treatment. The maximum and minimum thickness of fruit peel was measured in the control and shading treatments, respectively. ZnO treatment reduced the thickness of the fruit peel by 30.8% compared to the control. The lowest temperature of fruit and leaf was measured in shading and ZnT treatment, respectively. The control treatment produced the lowest Fv/Fm and leaf area, (LA), and the shading treatment resulted the highest Fv/Fm, LA and chlorophyll. ZnO treatment increased Fv/Fm and LA by 11.95% and 15.55%, respectively, compared to the control. The highest anthocyanin and phenol of juice were recorded in shading treatment. The highest fruit peel phenol and the lowest fruit peel lipoxygenase activity were measured in the ZnTK treatment. The results indicated that the ZnO treatment is a suitable treatment due to the decrease in the percentage of fruit peel and the increase in the Fv/Fm and the decrease in the activity of the lipoxygenase enzyme.

a factorial pot experiment was conducted in the form of a complete random block design with three repetitions under greenhouse condition. The first factor of the study was mycorrhiza at three levels, namely control (no mycorrhiza), Glomus intraradices strain, and Glomus mosseae strain. The second factor of the study included three levels of humic acid, namely 0 (control), 15, and 30 mg L-1. The results showed that with the application of mycorrhiza and humic acid, the number of seeds per plant, seed weight per plant, chlorophyll index, percentage of seed protein content, and nitrogen, phosphorus, and potassium contents of leaves increased. The highest seed weight per plant (13.47 g) was recorded in the red beans treated with 30 mg L-1 of humic acid + Glomus intraradices strain and 13.01 g and 13.72 g in the plants treated with 15 and 30 mg L-1 of humic acid, respectively along with Glomus mosseae strain. Also, the highest percentage of seed protein was 26.15% obtained from the treatment with 30 mg L-1 of humic acid + Glomus intraradices and 25.23% and 27.93% in the treatments with 15 mg L-1 and 30 mg L-1 of humic acid, respectively along with Glomus mosseae. Maximum leaf nitrogen content (5.85%) was obtained from the application of 30 mg L-1 of humic acid with Glomus mosseae. Mycorrhizae and humic acid seem to be able to improve the yield and yield components of red beans by providing nutrients to the plant

Gazania, belongs to the family Asteraceae, is widely grown in gardens and other environments. The purpose of this study was to evaluated the effects of sodium nitroprusside and potassium silicate treatments on the growth and flowering of gazania. For these purposes, a completely randomized design was used, with three levels of sodium nitroprusside (SNP) (25, 50 and 100 μM/l), potassium silicate (PS) at the concentration of 25, 50 and 100 mg/l and control. Some important traits such as fresh and dry weight of shoot and root, number of flowers, root volume, longest root length, plant height, cell membrane stability index, petiole carotenoid, leaf chlorophyll, protein, superoxide dismutase (SOD) and peroxidase (POD) enzyme activity and flower longevity. It was observed that plan that shoot fresh/dry weight, flower number, root length, plant height, carotenoid, leaf chlorophyll was increased under 100 mg/l PS treatment. The results suggest that the application of 50 μM/l SNP has favorable effects on the raise root fresh/dry weight, root volume, cell membrane stability index, protein, SOD and POD activity. Over the growth stage, 50 mg/l PS was found to be the best treatment to maintain flower longevity with 7.2 days.

The disadvantages encoutered for the multiplication of the Argan tree are the embryonic and integumentary dormancy, which directly affects the rate and the delay of germination, the standards of aggregation of the plants for the reforestation and in parallel on the stay time in the nursery. The study was conducted on Argan tree (Argania spinosa (L) Skeels) seedlings from two types of experimental germination of the kernels in the nursery: one pre-treatment with hot water and the second without pre-treatment (control); the aim is to see the effect of the duration of germination on the growth of the seedlings. The walnuts germinating for a short time gave plants of almost convergent height (varying from 23 to 25 cm), i.e., the average height was very representative and similar to the height of their plants (24.94 cm). On the other hand, walnuts with a long germination period produced seedlings of varying heights (ranging from 09 to 27 cm), with an average height different from their range of seedlings (17.46 cm). Regarding diameter growth, germination time did not affectyoung plants. When the germination period is short, it is possible to obtain homogeneous seedlings that meet phytotechnical standards for reforestation. According to this study, Argan seedlings should not be kept in the nursery for more than 33 weeks (08 months); otherwise, there is a risk of a poorly formed root system.

A plant’s response to osmotic stress is a complex phenomenon that causes many abnormal symptoms due to limitations in growth and development or even the loss of yield. The present study was designed to investigate the morpho-physiological responses of different sugar beet cultivars (‘Shokofa’, ‘Sina’, ‘Paya’, ‘Turbata’, and ‘Aria’) to priming (non-priming, osmopriming, and hydro-priming) and salinity of irrigation water (>2, 8, and 16 dS/m). The experiment was conducted as a factorial split plot experimental based on a randomized complete blocks design (RCBD) implemented in three replications in a research farm in Saveh city, Iran, during 2019-2020. Results showed that non-priming of ‘Shokofa’ genotype, hydro-priming of ‘Aria’ genotype, and osmo-priming of ‘Paya’ genotype under non-salinity conditions had the highest total chlorophyll content (31.04, 32.80, and 28.50 µg/g FW, respectively). The highest proline content was related to the hydro-and osmo-priming of seeds under high salinity stress (1.91 and 1.23 μmol/g FW, respectively). Hydro-priming of ‘Shokofa’ seed showed the highest LAI under the high salt stress level. The highest root yield (62.9 tons/ha) was observed in the hydro-priming of ‘Aria’ genotype under without salt stress conditions. In addition, all sugar beet cultivars under non-stress and hydro-priming conditions had the highest root yield. Among the cultivars, ‘Sina’, ‘Torbata’, and ‘Aria’ and hydro-priming technique are recommended for planting in areas under soil or irrigation water salinity stress

Physiological traits of tomato including its resistance to stresses are a main breeding goal in producing new cultivars. This study reports on a combining ability analysis investigating the variance of general and specified combing abilities for some important physiological characteristics as a whole as well as their effects for individual parents and hybrids of 19 tomato genotypes of tomato under drought stress. Three commercial innate lines and four analyzers were used in a line-to-tester crossing plan at Ilam University, Iran. There was a significant difference between genotypes (parents and crosses) in all characteristics at three levels of stress. Evaluating the impacts of common combining capacity analyzers and lines showed that neither a single line nor an analyzer was a commendable common combiner for all of the characteristics examined at all three push levels. Estimation of the effects of specific combining ability indicated that for each specific physiological trait, a specific hybrid showed the highest effect at all three stress levels. In all of the traits under study, specific combining ability variance had a higher estimation than general combining ability variance, and the genetic variance ratio of additive variance to non-additive variance was smaller than one, indicating that non-additive gene action predominated in the inheritance of all of the characteristics in the three levels of stress. The degree of dominance under three levels of stress was higher than one for all attributes except total soluble solids, and it seems that dominance in the genetic locations controlling these traits is superseded.

Root cultures were established through adventitious roots obtained either from direct or indirect organogenesis. The frequency of root response, number of roots per explant, root length, and zerumbone production were influenced by the concentrations and the types of auxins, initial root inoculum and the strength of the basic Murashige and Skoog (MS) salt in the culture media. It was crucial to decide the type of root explant and optimum media that supported both growth and bioactive compound production in the root cultures. In our study, we found that there was a noncorrelation in the optimised media for growth and zerumbone production in the root cultures of medicinal ginger Zingiber zerumbet Smith. Full strength (MS) medium was the optimum media for specific growth rates whereas zerumbone accumulation was higher in half strength MS medium for adventitious roots from direct (AdRD) and indirect (AdRId) organogenesis. AdRD was chosen over AdRId although the specific growth rate achieved was higher in the latter (7.2 x 10-2µ) than the former (5.5 x 10-2µ) based on the zerumbone accumulation performance. Subsequently, these AdRD root cultures were elicitated with methyl jasmonate which showed ten-folds increase in zerumbone production than the controls. This study could provide a scalable protocol for the production of zerumbone from adventitious root culture in the future.

Survival of humans and improvement of their standard of living require an awareness of the role of environment, acknowledgement of its importance in our lives, and development of a positive attitude to preserve and improve its quality. In order to protect or reconstruct the environment, first of all, human groups need to be trained. Environmental education can strengthen a culture of responsibility towards protection of both immediate environment and the entire planet, which is necessary for sustainable development. The purpose of environmental education is to raise individuals who are aware of environmental issues and to create a sense of responsibility in them to protect and support the environment. Rather than an attempt to increase theoretical knowledge in its audience, environmental education needs to aim at empowering people to identify environmental issues, critically analyze them, explore the viable solutions, and actually contribute in solving them. Environmentally educated citizens are environmentalist partners that can inform their families about environmental issues and transfer their experiences to the family environment. With an environment protection orientation and internalized sensitivity to preserve the environment, the next fathers and mothers will then transmit the green mindset to the subsequent generation.