Differential response of root morphology to potassium deficient stress among rice genotypes varying in potassium efficiency
Differential response of root morphology to potassium deficient stress among rice genotypes varying in potassium efficiency
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DOI：
10.1631/jzus.b0710636
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发表时间：
2008-05-01
影响因子：
5.1
通讯作者：
Jilani, Ghulam
中科院分区：
文献类型：
--
作者：
Jia, Yan-bo;Yang, Xiao-e;Jilani, Ghulam
研究了水培中钾 (K) 效率不同的 6 种水稻 (Oryza sativa L.) 基因型在 5 mg/L（低）、10 mg/L（中）和 40 mg/L（充足）三种 K 水平下根系形态的差异。形态参数包括根长、表面积、侧根体积和数量，以及细根（直径 < 0.2 毫米）和粗根（直径 > 0.2 毫米）。结果表明，低钾条件下所有基因型的根系生长均减少，但中度缺钾使高效基因型的根长增加。在缺乏和中等钾水平下，所有高效水稻基因型都比低效水稻基因型发育出更多的细根（直径 < 0.2 毫米）。研究发现，细根数和根表面积是描述水稻钾胁迫的最佳参数。根据根形态，当在中等和缺乏钾水平下生长时，有效基因型的芽中观察到较高的钾浓度，这表明根形态参数涉及根对钾的吸收以及钾向芽的易位。缺钾不仅影响根系形态，还影响根系超微结构。高效基因型的根系对缺钾胁迫造成的根膜损伤具有较强的耐受性，能够维持发达的根系结构以适应低钾生长介质。
Disparity in the root morphology of six rice (Oryza sativa L.) genotypes varying in potassium (K) efficiency was studied with three K levels: 5 mg/L (low), 10 mg/L (moderate) and 40 mg/L (adequate) in hydroponic culture. Morphological 'parameters included root length, surface area, volume and count of lateral roots, as well as fine (diameter < 0.2 mm) and thick (diameter > 0.2 mm) roots. The results indicate that the root growth of all genotypes was reduced under low K, but moderate K deficiency increased the root length of the efficient genotypes. At deficient and moderate K levels, all the efficient rice genotypes developed more fine roots (diameter < 0.2 mm) than the inefficient ones. Both fine root count and root surface area were found to be the best parameters to portray K stress in rice. In accordance with the root morphology, higher K concentrations were noted in shoots of the efficient genotypes when grown at moderate and deficient K levels, indicating that root morphology parameters are involved in root uptake for K and in the translocatio of K up to shoots. K deficiency affected not only the root morphology, but also the root ultra-structure. The roots of high-efficient genotypes had stronger tolerance to K deficient stress for root membrane damage, and could maintain the developed root architecture to adapt to the low K growth medium.