CSIRO Agriculture Flagship, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, Qld, 4067, Australia.
School of Agriculture and Food Science, The University of Queensland, St Lucia, Qld, 4072, Australia.
Glob Chang Biol. 2015 Aug;21(8):3126-37. doi: 10.1111/gcb.12927. Epub 2015 Jun 8.
Warmer temperatures associated with climate change are expected to have a direct impact on plant pathogens, challenging crops and altering plant disease profiles in the future. In this study, we have investigated the effect of increasing temperature on the pathogenic fitness of Fusarium pseudograminearum, an important necrotrophic plant pathogen associated with crown rot disease of wheat in Australia. Eleven wheat lines with different levels of crown rot resistance were artificially inoculated with F. pseudograminearum and maintained at four diurnal temperatures 15/15°C, 20/15°C, 25/15°C and 28/15°C in a controlled glasshouse. To quantify the success of F. pseudograminearum three fitness measures, these being disease severity, pathogen biomass in stem base and flag leaf node, and deoxynivalenol (DON) in stem base and flag leaf node of mature plants were used. F. pseudograminearum showed superior overall fitness at 15/15°C, and this was reduced with increasing temperature. Pathogen fitness was significantly influenced by the level of crown rot resistance of wheat lines, but the influence of line declined with increasing temperature. Lines that exhibited superior crown rot resistance in the field were generally associated with reduced overall pathogen fitness. However, the relative performance of the wheat lines was dependent on the measure of pathogen fitness, and lines that were associated with one reduced measure of pathogen fitness did not always reduce another. There was a strong correlation between DON in stem base tissue and disease severity, but length of browning was not a good predictor of Fusarium biomass in the stem base. We report that a combination of host resistance and rising temperature will reduce pathogen fitness under increasing temperature, but further studies combining the effect of rising CO2 are essential for more realistic assessments.
气候变化导致的温度升高预计将直接影响植物病原体,对未来的作物产生挑战,并改变植物病害的特征。在这项研究中,我们调查了温度升高对禾谷镰刀菌(Fusarium pseudograminearum)致病适应性的影响,禾谷镰刀菌是一种重要的坏死性植物病原体,与澳大利亚小麦冠腐病有关。我们用 11 种具有不同程度冠腐病抗性的小麦品种人工接种禾谷镰刀菌,并在控制温室中分别在四个昼温(15/15°C、20/15°C、25/15°C 和 28/15°C)下维持。为了量化禾谷镰刀菌的成功,我们使用了三个适应性测量指标,分别是病害严重度、茎基部和旗叶节点的病原体生物量,以及成熟植株茎基部和旗叶节点的脱氧雪腐镰刀菌烯醇(DON)。禾谷镰刀菌在 15/15°C 时表现出更高的整体适应性,随着温度的升高适应性逐渐降低。病原体适应性受到小麦品种冠腐病抗性水平的显著影响,但随着温度的升高这种影响会减弱。在田间表现出较高冠腐病抗性的品种通常与整体病原体适应性降低有关。然而,小麦品种的相对表现取决于病原体适应性的测量指标,与一种病原体适应性降低的指标相关的品种并不总是会降低另一种指标。茎基部组织中的 DON 与病害严重度之间存在很强的相关性,但茎基部的褐变长度并不能很好地预测镰刀菌生物量。我们报告说,在温度升高的情况下,寄主抗性和温度升高的组合将降低病原体适应性,但进一步结合 CO2 升高的研究对于更现实的评估是必不可少的。