Characterization of a rice variety with high hydraulic conductance and identification of the chromosome region responsible using chromosome segment substitution lines
Characterization of a rice variety with high hydraulic conductance and identification of the chromosome region responsible using chromosome segment substitution lines
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DOI：
10.1093/aob/mcq175
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发表时间：
2010-11-01
期刊：
影响因子：
4.2
通讯作者：
Hirasawa, Tadashi
中科院分区：
文献类型：
--
作者：
Adachi, Shunsuke;Tsuru, Yukiko;Hirasawa, Tadashi
由于水分胁迫，水稻的光合作用速率在晴天的中午经常下降，即使在淹水条件下。在白天维持较高的光合速率可以提高水稻产量和干物质生产。高产籼稻品种“Habataki”在白天保持较高的叶片光合速率，这是因为从根到叶的水力传导比标准粳稻品种“Sasanishiki”高。本研究通过对“Habataki”高导水率的染色体定位，确定了高导水率的染色体区域，并分别测定了强蒸腾作用下和非蒸腾作用下植物对被动水运输和渗透水运输的导水率。从根表面积和水力传导度（单位根表面积的水力传导度，L-p）方面检查了水力传导度的品种差异。为了确定高导水率的染色体区域，我们使用了来自'Sasanishiki'和'Habataki'杂交的染色体片段代换系（CSSLs）。在4号染色体长臂上的RM 3916和RM 2431之间检测到与水力导度升高相关的染色体区域。在“Sasanishiki”的背景中，将“Habataki”的染色体片段替换为“CSSL”，其根质量比“Sasanishiki”大。“Habataki”具有增加植物导水率，从而在强蒸腾条件下保持较高的叶片光合速率的性状。并且估计至少有一个位于4号染色体上的性状的染色体区域。
The rate of photosynthesis in paddy rice often decreases at noon on sunny days because of water stress, even under submerged conditions. Maintenance of higher rates of photosynthesis during the day might improve both yield and dry matter production in paddy rice. A high-yielding indica variety, 'Habataki', maintains a high rate of leaf photosynthesis during the daytime because of the higher hydraulic conductance from roots to leaves than in the standard japonica variety 'Sasanishiki'. This research was conducted to characterize the trait responsible for the higher hydraulic conductance in 'Habataki' and identified a chromosome region for the high hydraulic conductance.Hydraulic conductance to passive water transport and to osmotic water transport was determined for plants under intense transpiration and for plants without transpiration, respectively. The varietal difference in hydraulic conductance was examined with respect to root surface area and hydraulic conductivity (hydraulic conductance per root surface area, L-p). To identify the chromosome region responsible for higher hydraulic conductance, chromosome segment substitution lines (CSSLs) derived from a cross between 'Sasanishiki' and 'Habataki' were used.The significantly higher hydraulic conductance resulted from the larger root surface area not from L-p in 'Habataki'. A chromosome region associated with the elevated hydraulic conductance was detected between RM3916 and RM2431 on the long arm of chromosome 4. The CSSL, in which this region was substituted with the 'Habataki' chromosome segment in the 'Sasanishiki' background, had a larger root mass than 'Sasanishiki'.The trait for increasing plant hydraulic conductance and, therefore, maintaining the higher rate of leaf photosynthesis under the conditions of intense transpiration in 'Habataki' was identified, and it was estimated that there is at least one chromosome region for the trait located on chromosome 4.