Genotypic variations in the plasticity of nodal root penetration through the hardpan during soil moisture fluctuations among four rice varieties
Genotypic variations in the plasticity of nodal root penetration through the hardpan during soil moisture fluctuations among four rice varieties
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DOI：
10.1080/1343943x.2018.1439757
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发表时间：
2018-01-01
影响因子：
2.5
通讯作者：
Yamauchi, Akira
中科院分区：
文献类型：
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作者：
Dinh Thi Ngoc Nguyen;Rodriguez Suralta, Roel;Yamauchi, Akira
雨养低地稻田的特点是土壤水分波动（SMF）和硬土层的存在，阻碍深根，从而限制了水分提取从深层土壤层在干旱期间。在这项研究中，我们使用的根盒与三个层;浅层，人工硬磐，和硬磐以下的深层和湿层，通过硬磐和促进硬磐以下的根分枝响应SMF四个水稻品种之间的可塑性差异进行评估; Sasanishiki，Habataki，Nipponbare，Kasalath。实验在夏季和秋季进行。可塑性被计算为SMF和连续良好浇水处理之间的每个品种内的根性状的差异。在这两个实验中，当土壤湿度增加而渗透阻力降低时，在SMF复水期间，通过增加穿透硬土层的节根数量，哈巴塔基始终倾向于表现出比其他三个品种更高的根可塑性。这种根的可塑性，然后在随后的干旱期间，在更深的土壤和整体地上部干物质生产更大的水分利用。在SMF条件下，Habataki深层根的δ C-13值显著高于浅层和硬土层根，这可能表明这些根是相对新生长的根，这是根可塑性的结果。本研究还表明，来自Sasanishiki和Habataki品种的CSSLs可能适用于分析与具有硬磐和经历SMF的低低地根系可塑性表达相关的QTL。
Rainfed lowland rice fields are characterized by soil moisture fluctuations (SMF) and the presence of hardpan that impedes deep rooting and thus limits water extraction from deep soil layer during the periods of drought. In this study, we used rootboxes with three layers; shallow layer, artificial hardpan, and deep and wet layer below the hardpan, to evaluate differences in the plasticity of nodal roots elongation through the hardpan and promote root branching below the hardpan in response to SMF among four rice varieties; Sasanishiki, Habataki, Nipponbare, and Kasalath. Experiments were conducted during the summer and autumn seasons. Plasticity was computed as the difference in root traits within each variety between the SMF and continuously well-watered treatments. In both experiments, Habataki consistently tended to exhibit higher root plasticity than the other three varieties by increasing number of nodal roots that penetrated the hardpan during rewatering period in SMF, when the soil moisture increased and penetration resistance decreased. This root plasticity then contributed to greater water use at the deeper soil during the subsequent drought period and overall shoot dry matter production. Habataki had significantly higher delta C-13 value in roots at deep layer than roots at the shallow and hardpan layers under SMF, which may indicate that these were relatively newly grown roots as a consequence of root plasticity. This study also indicates that CSSLs derived from Sasanishiki and Habataki varieties may be suitable for the analysis of QTLs associated with root plasticity expression in rainfed lowland with hardpan and experiencing SMF.