关键词: 平邑甜茶, 根系构型, 营养吸收, 根域形状

Abstract: 【Objective】Root system architecture is an important morphological characteristic of root system and an important factor affecting plant nutrient absorption. The root morphology, architecture and root nutrient uptakes can be influenced by cultivation containers with specific shapes. The Malus hupehensis (Pamp) Rehd. is a good apple stock and sensitive to the environment of root zone. The project aimed to investigate the effect of different root zone shapes on shoot growth, parameters of root system architecture and nutrient uptakes of roots in M. hupehensis, for providing a basis for analyzing and creating ideal root architecture and improving the nutrient absorption and plant growth of apple stock. 【Method】 Different clay pots were used to set three root zones with different shapes, such as the ‘root zone of deep-narrow’ was set by the clay pot with the sizes of pot-diameter less than the pot height, the ‘root zone of shallow-wide’ was set by the clay pot with the sizes of pot diameter more than the pot height, the ‘root zone of equal height and diameter’ was set by the clay pot with the sizes of pot-diameter equal to pot height. In the early spring, the three different clay-pots were filled by similar nutrient soil with the same volume, respectively, and then the seedlings of M. hupehensis (Pamp) Rehd. with similar growth and roots were transplanted into the pots, respectively. The root morphology root architecture, shoot growth, root activity and root nutrient absorption rate were investigated after eight months of transplanting. 【Result】 The shoot growth, root architecture and nutrient absorption characteristics of the seedlings were significantly different after 8 months of growth in the three root zones with different shapes. When seedlings grown in the ‘root zone of deep-narrow’, the root top ratio was the biggest, the first and the second lateral roots were the shortest, the number of the first lateral root was more; the root activity and the potassium-uptake rates of the roots were the lowest, and the root uptake rates of phosphorus, calcium and zinc were lower and the iron-uptake ability of the roots was higher. When seedling grown in the ‘root zone of shallow-wide’, the shoots were thicker, longer and more leaves, and shoots grew the fastest, and the root/top ratio was smaller; the first and the second lateral roots were the thickest and longest, the number of the second lateral roots and fine roots was more; the potassium-uptake rate was the highest, the uptake rate of phosphorus and zinc were higher, the calcium-uptake rate of the roots were lower, and the iron-uptake ability of the roots was the lowest. When seedling grown in the ‘root zone of equal height and diameter’, the shoots were thinner, shorter and less leaves, and shoots grew the slowest, the root/top ratio was smaller; taproot was the thinnest, the number of the first lateral root and fine roots was less; the root activity was the highest, the uptake rates of calcium and zinc of the roots were higher, and the uptake rates of phosphorus, potassium and iron were lower. 【Conclusion】 There was a significant effect of root zone shape on the root morphology, root architecture, nutrient uptake, root/top ratio and shoot growth. The ‘root zone of deep-narrow’ decreased the length and diameter of lateral roots, increased the number of first lateral roots and the root/top ratio and improved the iron-uptake. The ‘root zone of shallow-wide’ increased the length and diameter of lateral roots, made fine roots richer, improved the uptake of phosphorus and potassium and promotes shoot growth. The ‘root zone of equal height and diameter’ decreased the diameter of taproot and the numbers of first lateral root and fine roots, promoted root activity and calcium-uptake.

Key words: Malus hupehensis (Pamp) Rehd., root architecture, nutrients uptake, root-zone shape