甬优系列籼粳杂交稻根系形态与生理特征

摘要

A field experiment was conducted to compare the root system morphological and physiological characteristics of four types of rice populations includingindica-japonica hybrid rice of Yongyou series (A),japonica hybrid rice (B), conventional japonica rice (C), andindica hybrid rice (D) under high-yielding cultivation condition in the rice-wheat cropping system. Results were as follows: (1) The root dry weight, aboveground dry weight, number of root tips, root length, root surface area, root-shoot ratio and root volume of A were obviously higher than those of B, C, and D at the middle and late growth stage. (2) The proportion of number, length, surface area and volume of the adventitious roots(root diameter > 0.3 mm) to the whole roots of A were higher than those of B and C, while lower than those of D at heading; the proportion of number, length, surface area and volume of the fine branches (root diameter≤ 0.1 mm) and coarse branches (0.1 mm < root diameter≤ 0.3 mm) to total roots of A were higher than those of D, while lower than those of B and C at heading. The proportions of root weight in 0–5 cm, 5–10 cm, and 10–15 cm soil layers to total roots weight of A were higher than those of B and C, while lower than those of D; however, the proportions of root weight in 15–25 cm, 25–35 cm, 35–45 cm, and 45–55 cm soil layers to the total root weight where lower than those of B and C, while higher than these of D at heading. (3) The total absorbing surface area, active absorbing surface area, bleeding intensity, root oxidation activity, and root reducing activity of A were higher than those of B, C, and D. Compared with B, C, and D, theindica-japonica hybrid rice of Yongyou series had significant advantage in root-shoot coordination level, root amount, branch structure, root distribution in soil and biological activity in the middle and late growth stage. This peculiarity of A provides an important guarantee to realize the super-high-yield.%以甬优籼粳杂交稻群体(A)为研究对象,在稻麦两熟制机插高产栽培条件下,以三系杂交粳稻群体(B)、超级常规粳稻(C)和超级杂交籼稻群体(D)为对照的试验,旨在揭示甬优系列籼粳杂交稻超高产根系形态生理特征。结果表明：(1)在生育中、后期, A的根系干重、地上部干重、根尖数、根系长度、根系表面积、根系体积及根冠比均显著高于B、C和D。(2)抽穗期不定根(根径>0.3 mm)的根尖数、根系长度、根系表面积和根系体积占总根的比例表现为A大于B和C,小于D；细分支(根径≤0.1 mm)与粗分支(0.1 mm＜根径≤0.3 mm)的根尖数、根系长度、根系表面积和根系体积占总根的比例均表现为A大于D,小于B和C。抽穗期土层0~5 cm、5~10 cm和10~15 cm范围根干重占根系总干重的比例表现为A大于B和C,小于D；土层15~25 cm、25~35 cm、35~45 cm、45~55 cm范围根干重占根系总干重的比例表现为A大于D,小于B和C。(3) A抽穗后根系总吸收面积、根系活跃吸收面积、根系伤流强度以及根系氧化力和根系还原力均高于B、C和D。与杂交粳稻、常规粳稻和杂交籼稻相比,甬优系列籼粳杂交稻具有根冠协调水平高、群体根量大、分支结构优、根系深扎性好以及中、后期生理活性强等优势,这种根系特征为其超高产的实现提供了重要保障。