Artificial Regulation Effect of Plant Retardants on Leaf Anatomical Characteristics of Elaeagnus Angustifolia

Aims: In order to explore the adaptation mechanisms of Elaeagnus angustifolia to the arid environment in desert areas under the treatment of artificial plant retardants, we used to investigate artificial regulation by using retardants of paclobutrazol (PP333), paclobutrazol+adhesive (NPP333), and chlormequat (CCC) based on multiple factors and multiple levels.Methods: Orthogonal experimental design of L-9 (3(4)) was used to design the experimental treatment combinations. Leaf morphological and structural characteristics determined by the paraffin section method were used to explain the effect of different treatments and their combinations.Results: The leaves of Elaeagnus angustifolia were iso-petalous with obvious stellate epidermal fuzzy borders on the upper epidermis. The palisade tissue was well developed and tightly arranged. The T1-T9 treatment significantly increased leaf thickness. Conversely, leaf length and width showed a delayed growth effect, while leaf growth developed as an elongated type after application. After plant retardant control, the upper epidermal, palisade tissue, and spongy tissue thickness of the leaves showed a significant trend to increase, at the same time, the number of xylem rows increased and the number of cells per row increased and were arranged closely. Meanwhile, there was a synergistic evolution phenomenon among the indexes. The best treatment combination of plant retardants to regulate the leaf configuration of plants was selecting the concentration of 600 mg/L of PP333, using the root application + leaf application method for two applications.Conclusions: The study showed that plant retardants improved the ability of plants to resist external environmental stress by reducing leaf area, increasing leaf and epidermal thickness, and promoting the development of mesophyll and vein structures in order to improve water retention capacity and prevent transitional transpiration.