Abstract：
Flooding caused by climate change puts the productivity of sugarcane cultivation at risk. The objective of this study was to evaluate the effect of in vitro flooding stress on sugarcane plantlets. Sugarcane plantlets were grown in test tubes containing Murashige and Skoog semi-solid medium without growth regulators as a control treatment and two stress levels using a double layer with sterile distilled water to simulate hypoxia and anoxia. After 15 d of culture, the number of new shoots, plantlet height, number of leaves, number of roots, root length, stomatal density, percentage of closed stomata and percentage of dry matter were evaluated. In addition, biochemical variables such as chlorophylls, carotenoids, phosphoenolpyruvate (PEP), Rubisco, total proteins (TP), proline (Pr), glycine-betaine (GB), phenols, antioxidant capacity and lipid peroxidation were determined in all treatments. Results showed a higher number of new shoots, leaves and percentage of closed stomata in the flooded plantlets, while plantlet height, number of roots, stomatal density, and dry matter were higher in the control treatment. Regarding, chlorophyll, carotenoid, PEP and Rubisco contents decreased in the flooded treatments, while TP and phenol contents were higher in the partially submerged treatment. Antioxidant capacity and lipid peroxidation increased in the fully submerged treatment. Pr and GB contents did not show changes in any of the evaluated treatments. Stress induced by excess water in a double layer in vitro is an alternative method to determining physiological and biochemical mechanisms of tolerance to hypoxia and anoxia caused by flooding for breeding programs in sugarcane.
摘要：
气候变化造成的洪水使甘蔗种植的生产力面临风险。本研究的目的是评估体外洪水胁迫对甘蔗植株的影响。甘蔗小植株在含有Murashige和Skoog半固体培养基的试管中生长，没有生长调节剂作为对照处理，并且使用带有无菌蒸馏水的双层模拟缺氧和缺氧。培养15d后，新芽的数量，植株高度,叶子的数量,根数,根长,气孔密度，评估了闭口气孔的百分比和干物质的百分比。此外,生化变量，如叶绿素，类胡萝卜素，磷酸烯醇丙酮酸(PEP)，Rubisco,总蛋白（TP），脯氨酸(Pr),甘氨酸甜菜碱（GB），酚类物质,在所有处理中都测定了抗氧化能力和脂质过氧化。结果显示新芽数量较多，淹没的小植株中的叶片和闭合气孔的百分比，而植株高度，根数,气孔密度，对照处理中干物质较高。关于,叶绿素,类胡萝卜素，在洪水处理中PEP和Rubisco含量降低，部分浸没处理的TP和苯酚含量较高。在完全浸没处理中，抗氧化能力和脂质过氧化作用增加。Pr和GB含量在任何评价的处理中均未显示变化。体外双层中过量水引起的胁迫是确定甘蔗育种计划中对洪水引起的缺氧和缺氧耐受性的生理和生化机制的替代方法。
