The Effects Of Plant Growth Regulator On Physiological Characteristics And Root Growth Of Aquilaria Sinensis And Ilex Rotunda

Aquilaria sinensis and Ilex rotunda are common native tree species for greening, and are becoming increasingly popular tree species for landscaping. However, for production, they are relatively difficult for transplanting. This study selected different types of plant growth regulators(ABT-3, NAA, IAA) in different concentrations(50 mg/L,100 mg/L, 150 mg/L) to treat these two species of seedlings and measured the indicators: net photosynthetic rate Pn, transpiration rate Tr, water use efficiency WUE, PSII actual quantum yield Y(II), relative electron transfer efficiency ETR, non-photo-chemical quenching NPQ, root activity, root length, root surface area and root volume, and meanwhile conducted comprehensive assessment on these indicators in order to study the influence of plant growth regulators on physiological characteristics changes and root growth of these two excellent native tree species. Eventually, we got the best plant growth regulator and its concentration that are most beneficial to the growth of Aquilaria sinensis and Ilex rotunda. This conclusion is of great significance in enhancing the planting or transplanting survival rate of these two excellent native tree species. The main research results are as follows:(1) In the aspect of the influence of the 3 types of plant growth regulators on the physiology and root growth of Aquilaria sinensis, we adopted principal component analysis to conduct comprehensive assessment. Calculation results showed that the best configuration combination in comprehensive ranking was the IAA solution in a concentration of 150 mg/L. Other solutions in the ranking were orderly ABT solution in a concentration of 50 mg/L, ABT solution in a concentration of 100 mg/L, NAA solution in a concentration of 50 mg/L, IAA solution in a concentration of 100 mg/L, NAA solution in a concentration of 100 mg/L, NAA solution in a concentration of 150 mg/L, IAA solution in a concentration of 50 mg/L, ABT solution in a concentration of 150 mg/L. The solution performed worst was the CK in control group, indicating that all combinations contribute to some extent to the physiology and root growth of aquilaria sinensis, yet when choosing plant growth regulators in production, we can choose top-ranking combinations.(2) In the aspect of the influence of the 3 types of plant growth regulators on the physiology and root growth of Ilex rotunda, we adopted principal component analysis to conduct comprehensive assessment. Calculation results showed that the best configuration combination in comprehensive ranking was the ABT solution in a concentration of 100 mg/L. Other solutions in the ranking were orderly IAA solution in a concentration of 100 mg/L, ABT solution in a concentration of 150 mg/L, NAA solution in a concentration of 50 mg/L, NAA solution in a concentration of 100 mg/L, ABT solution in a concentration of 50 mg/L, NAA solution in a concentration of 150 mg/L, CK solution in control group, IAA solution in a concentration of 50 mg/L, IAA solution in a concentration of 150 mg/L, indicating that IAA solution in a concentration of 50 mg/L, IAA solution in a concentration of 150 mg/L had inhibitory effect on physiology and root growth of Ilex rotunda, while other combinations all to some extent facilitated the physiology and root growth of Ilex rotunda. Comprehensively, when selecting plant growth regulator for Ilex rotunda, the best combination is the ABT solution in a concentration of 100 mg/L.In summary, for Aquilaria sinensis, the combinations that can be selected are the IAA solution in a concentration of 150 mg/L, ABT solution in a concentration of 50 mg/L and ABT solution in a concentration of 100 mg/L. For Ilex rotunda, the combinations that can be selected are the ABT solution in a concentration of 100 mg/L, IAA solution in a concentration of 100 mg/L, ABT solution in a concentration of 150 mg/L. The combinations of growth regulators and concentrations can better enhance the transplanting survival rate of these two plants.