Abstract

Climate change has become one of the biggest environmental challenges facing the world, disrupting the growth and development of plants. The phenomenon of dust has emerged as a serious threat in recent years. With increasing global temperatures, decreasing rainfall, increasing evaporation and transpiration, and excessive and improper use of water in many human activities, the number of arid and semi-arid areas around the world has increased. This phenomenon causes enormous damage to farms, the environment, facilities, and people's lives every year, increases evaporation, and causes drying of the upper soil layer, destruction of agricultural lands, expansion of deserts, and pollution of surface water resources. In recent years, the ability of salicylic acid to provide a protective effect in plants under abiotic stresses has been investigated. Salicylic acid is known as a promising molecule for improving abiotic stress tolerance in plants due to its ability to enhance the antioxidant defense system and promote root structure. Durum wheat (Triticum durum Desf.) is known as one of the important crops of the cereal family, with an annual production of about 40 million tons in the world.

Materials and Methods

An experiment was conducted in the greenhouse of Ilam University as a factorial in a completely randomized basic design with four replications to investigate the effect of salicylic acid foliar spraying in modulating the effect of dust on durum wheat. The experimental factors included wheat cultivars (4 genotypes), dust at five levels (control, once, twice, three times, and four times), and salicylic acid treatment at three levels (0, 50%, and 100%).

Results

The results showed that the highest spike length was obtained in genotype TRI 10519 and 100 ppm salicylic acid application and three times of dust stress (9.8 cm) and the lowest was obtained in genotype TRI 11020 in three times of dust stress and 50 ppm salicylic acid application (4.3 cm). The highest relative leaf water content was observed in genotype TRI 14231 and 100 ppm salicylic acid application and three times of dust stress (96.3 percent) and the lowest was observed in genotype TRI 10519 without dust stress and without salicylic acid application (31.31 percent). Also, the highest amount of carotenoids was obtained in TRI 11020, no salicylic acid application and no dust stress (2.9 mg/g wet weight), and the lowest amount was obtained in TRI 14231, no dust stress and 100 ppm salicylic acid application (0.5 mg/g wet weight).

Conclusion

The results of this study indicate the importance of balance and interaction between genotype, salicylic acid, and environmental factors such as dust in regulating plant growth. In general, and according to the results obtained from the present study, it can be said that in order to obtain the highest internode length and flag leaf length under dust stress conditions, the TRI 14246 genotype and the application of salicylic acid are recommended, and in order to obtain the highest amount of carotenoid pigments and chlorophyll a and b under dust stress conditions, the TRI 11020 genotype and the application of salicylic acid, as well as the highest bract length, relative leaf water content, and proline under dust stress conditions, the TRI 14231 genotype is recommended.