| Phoebe hui is a precious timber and ornamental tree species in China,but its resources are very rare.In this study,the annual container seedlings of Phoebe hui were used as experimental materials,15 formulas were used for conventional fertilization,T10 formula and total amount of fertilizer were used to set nitrogen index fertilization group T16,and CK was used as the control.The growth,root system,elements,photosynthesis,fluorescence and physiological indexes of annual container seedlings of Phoebe hui were measured.The effects of different fertilization on the growth and physiology of annual container seedlings of Phoebe hui were studied by using seedling quality index,principal component analysis,membership function and other comprehensive evaluation methods,in order to find out the suitable fertilization scheme for the growth of annual container seedlings of Phoebe hui.The major results as follow:(1)Scientific and reasonable fertilization can significantly promote the growth of annual container seedlings of Phoebe hui.Compared with CK,the seedling height,ground diameter,leaf area,above-ground biomass,underground biomass and total biomass of fertilization group were basically higher.The seedling height of T10 and T16 were 25.36%and 37.46%higher than CK,the ground diameter was 34.15%and 44.72%higher than CK,the leaf area was 67.48%and 72.70%higher than CK,the aboveground biomass was 62.50%and 95.83%higher than CK,the underground biomass was 60.00%and 115.00%higher than CK,and the total biomass was 59.09%and 104.55%higher than CK.Under the condition of the same fertilization formula,index fertilization is better than conventional equal fertilization.(2)The fertilization treatment had obvious effects on the five indexes of the root system of annual container seedlings of Phoebe hui.Fertilization could increase the activity of root tip cells,the total root length,total root surface area,average root diameter,and total root volume.And it can promote the growth of root system.The minimum value of the five root indexes was CK.The root activity and total root surface area of T10 were 22.05%and 70.49%higher than CK,respectively,reaching the maximum in the group.The total root length,average root diameter and total root volume of T16 were 109.47%,79.17%and 165.91%higher than CK,respectively,reaching the maximum in the group.(3)The contents of N,P,K,Ca and Mg in leaves,stems and roots were also different in different fertilization groups.The Le value of total contents of N,P,K,Ca and Mg in leaves was the highest in treatment group T10(g/plant N:1.6/P:1.6/K:0.9),which was 43.48%higher than the lowest CK;the se value of total contents of N,P,K,Ca and Mg in stems was the highest in treatment group T8(g/plant N:1.6/P:0.0/K:0.9),which was 41.60%higher than the lowest CK;the re value of total contents of N,P,K,Ca and Mg in roots was the highest The maximum treatment group was T9(g/plant N:1.6/P:0.8/K:0.9),which was 44.18%higher than CK in the 14th place.The nutrient element content of each organ was increased after fertilization.(4)Reasonable fertilization can effectively increase chlorophyll content,stomatal openness,reduce water loss by regulating transpiration,improve the absorption and utilization of light energy under the condition of unit transpiration water,and enhance the relative electron transfer rate,photosynthetic activity and actual light energy conversion efficiency in photosystem Ⅱ,improve the net photosynthetic rate Pn,T10 and T16 had the strongest photosynthetic capacity,while CK had the worst.T10 and T16,which were the highest in the total mean value of Pn in June,August and October,were 43.48%and 39.51%higher than CK,which was the lowest.(5)Compared with the no fertilization CK,the content of soluble sugar and soluble protein in each group was higher,which could effectively improve the nutrient content in the leaves of the annual container seedlings young leaves of Phoebe hui,resistance of seedlings,and reduce the MDA content in the plant.In June,August and October,T16 and T10 with the highest total average content of soluble protein SP were 185.63%and 163.26%higher than CK with the lowest total average content;T10 and T16 with the highest total average content of soluble sugar SS were 32.51%and 30.17%higher than CK with the lowest total average content of MDA were 44.52%and 41.98%lower than CK with the highest total average content of MDA.(6)According to the growth status and comprehensive score ranking,the growth of the treatment group with N fertilizer and without P fertilizer(T4、T8、T12)was better than the treatment group with P fertilizer and without N fertilizer(T1、T2、T3),which indicated that N fertilizer has higher effect on promoting seedling growth than P fertilizer in this experiment.(7)The above results showed that both lower and higher fertilization rates are not conducive to the growth of seedlings.T16 and T10 with medium fertilization rate showed the best growth status and seedling quality,and T16 was better than T10 in this study.In the summary,the most suitable fertilization formula was N2P2K(g/plant N:1.6/P:1.6/K:0.9),and the best fertilization method was exponential fertilization. |
