Interaction of root-traits related QTL with soil stress factors in rainfed lowland and upland rice

根系在作物适应各种非生物胁迫（如水分胁迫）中发挥着重要作用，但负责这种适应的性状可能因环境而异。本研究旨在鉴定根系性状及其相关QTL，并评价其与土壤水分胁迫的相互作用。我们对菲律宾水稻的遗传资源进行了广泛的调查，并评估了它们对水分胁迫条件的反应。然后，我们确定了根系可塑性是适应的关键性状之一，并且是与chr 6上的分支相关的QTL。田间试验表明，雨养低地条件下干物质产量较高的基因型可能在土壤有效水分较多的土壤深处表现出根系可塑性。在观察到较深土层根系塑性的情况下，这种根系塑性发育可能是在土壤湿度波动期间土壤湿度较高时土壤硬度降低的反应。

Roots play important roles in crop adaptation to various abiotic stresses such as water stress, but traits responsible for such adaptations may differ with environments. This study aimed at identifying the root traits and their associated QTL, and evaluating their interactions with soil water stresses. We made an extensive survey on genetic resources in rice in the Philippines and evaluated their responses to water stress conditions. We then identified the root plasticity as one of the key traits for adaptation and a QTL that is related with branching on chr 6. Field experiments showed the genotype that showed greater dry matter production under rainfed lowland conditions may have exhibited the root plasticity at soil depths with more available soil moistures. In cases where root plasticity at deeper soil layers were observed, such root plastic development may have occurred in response to the reduction of soil hardness when the soil moisture was high during soil moisture fluctuations.