Genotypic variation in root growth angle in rice (Oryza sativa L.) and its association with deep root development in upland fields with different water regimes
Genotypic variation in root growth angle in rice (Oryza sativa L.) and its association with deep root development in upland fields with different water regimes
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DOI：
10.1007/s11104-006-9008-4
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发表时间：
2006-09-01
期刊：
影响因子：
4.9
通讯作者：
Yamagishi, Junko
中科院分区：
文献类型：
--
作者：
Kato, Yoichiro;Abe, Jun;Yamagishi, Junko
深根发育对水稻抗旱性具有重要意义，是一个复杂的性状结合各种根形态。本研究的目的是阐明深根发育的基因型差异与形态指标，如垂直根分布和根生长角度。进行了两个试验：一个在高地，一个在盆和田。试验一对6个旱稻品种在不同水分条件下（水灌和穗发育期间歇干旱）的根系生理形态进行了分析。在试验2中，采用篮子法在灌溉条件下对12个品种的根系生长角进行了品种差异评价。实验1中，灌溉和干旱条件下的总根长或深根长没有发现品种与环境的互作。这表明，组成根的生长，这是遗传决定的，是重要的深根发育在间歇性干旱条件下生殖阶段。在根系性状中，深根比（i.例如，深根重除以总根重）与深根长的关系最为密切。这说明根系的垂直分布对深根长度有显著的影响。试验2中高地的节根直径和根生长角存在显著的基因型差异。在旱地，粗根基因型通过根系生长角度向深层根系分配更多的同化物。本文首次报道了水稻根生长角的基因型变异。由于根系生长角的测定快速简便，因此，该方法可用于高地根系垂直分布基因型变异的粗略估计。
Deep root development, which is important for the drought resistance in rice ( Oryza sativa L.), is a complex trait combining various root morphologies. The objective of this study was to elucidate genotypic variation in deep root development in relation to morphological indicators such as vertical root distribution and root growth angle. Two experiments were conducted: one on upland fields, and one in pots and fields. In experiment 1, the root systems of six rice cultivars on upland fields were physio- morphologically analyzed under different water regimes ( irrigated and intermittent drought conditions during panicle development). In experiment 2, cultivar differences in root growth angles were evaluated with 12 cultivars using the basket method under irrigated conditions. No cultivar x environment interactions were found for total root length or deep root length between irrigated and drought conditions in experiment 1. This suggests that constitutive root growth, which is genetically determined, is important for deep root development under intermittent drought conditions during reproductive stage. Among root traits, the deep root ratio ( i. e., deep root weight divided by total root weight) was most closely related to deep root length under both water regimes. This suggested that vertical root distribution constitutively affects deep root length. Significant genotypic variation existed in the nodal root diameter and root growth angle of upland rice in experiment 2. It was considered that genotypes with thick roots allocated more assimilates to deep roots through root growth angles higher to the horizontal plane on upland fields. This is the first report on genotypic variation in the root growth angle of rice on upland fields. It should prove useful for rough estimations of genotypic variation in the vertical root distribution of upland rice because root growth angle is rapidly and easily measured.