Zhao Haochen, Sharmita Onusha, Siddique Abu Bakar, Shabala Sergey, Zhou Meixue, Zhao Chenchen
Tasmanian Institute of Agriculture, University of Tasmania, Newnham Drive, Launceston, TAS 7248, Australia.
International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528000, China.
Plants (Basel). 2025 Aug 25;14(17):2641. doi: 10.3390/plants14172641.
Canola is an important rotation crop in Australia's high-rainfall zone (HRZ), where frequent waterlogging occurs. Due to its lack of aerenchyma, canola is more vulnerable to waterlogging. Recent studies have shown that nitrogen supplementation can benefit crop growth under waterlogging stress. However, limited reports have addressed the physiological responses and macronutrient changes in either winter or spring canola with strategically timed fertilizer applications. This study investigated the physiological and elemental responses of two canola genotypes to nitrogen application at different timings during waterlogging stress. By imposing waterlogging stress in pot-based trials for 21 days using spring-type (Dynatron) and winter-type (Nizza) canola, our results demonstrated that nitrogen application one week prior to the onset of waterlogging marginally improved soil plant analysis development (SPAD) values in the two types of canola, but only significantly enhanced stomatal conductance along with reduced photosynthetic efficiency in Dynatron at the end of waterlogging, indicating genotypic differences. Furthermore, applying fertilizer a week before waterlogging enhanced macronutrient accumulation in Dynatron, including phosphorus, potassium, magnesium, and calcium. In contrast, Nizza only exhibited a significant increase in magnesium accumulation. Fertilizer application had no effect on reducing Mn and Fe accumulation in canola, indicating that Mn and Fe toxicity, typically associated with soil waterlogging, was not a contributing factor in nitrogen-induced waterlogging alleviation. Collectively, our results demonstrated genotype-specific nutrient dynamics, which should be considered in nitrogen-induced waterlogging alleviation.
油菜是澳大利亚高降雨区（HRZ）的一种重要轮作作物，该地区经常发生涝灾。由于油菜缺乏通气组织，它更容易受到涝灾影响。最近的研究表明，补充氮素在涝渍胁迫下有利于作物生长。然而，关于冬油菜或春油菜在战略施肥时间下的生理反应和大量养分变化的报道有限。本研究调查了两种油菜基因型在涝渍胁迫期间不同时间施氮的生理和元素反应。通过在盆栽试验中对春型（Dynatron）和冬型（Nizza）油菜施加21天的涝渍胁迫，我们的结果表明，在涝渍开始前一周施氮略微提高了两种油菜的土壤植物分析发展（SPAD）值，但仅在涝渍结束时显著提高了Dynatron的气孔导度，同时降低了光合效率，表明存在基因型差异。此外，在涝渍前一周施肥增加了Dynatron中大量养分的积累，包括磷、钾、镁和钙。相比之下，Nizza仅表现出镁积累的显著增加。施肥对降低油菜中锰和铁的积累没有影响，这表明通常与土壤涝渍相关的锰和铁毒性不是氮诱导减轻涝渍的一个因素。总体而言，我们的结果表明了基因型特异性的养分动态，这在氮诱导减轻涝渍中应予以考虑。
