Robert Corinne, Bancal Marie-Odile, Nicolas Pierre, Lannou Christian, Ney Bertrand
Environnement et Grandes Cultures, INRA, F-78850 Thiverval Grignon, France.
J Exp Bot. 2004 May;55(399):1079-94. doi: 10.1093/jxb/erh108. Epub 2004 Apr 8.
A model to predict Septoria tritici blotch (STB) and leaf rust effects on wheat growth was constructed and evaluated in two steps. At the leaf scale, Bastiaans' approach that predicts the relative photosynthesis of a wheat leaf infected with a single disease, was extended to the case of two diseases, one biotrophic and one necrotrophic by considering the leaf rust-STB complex. A glasshouse experiment with flag leaves inoculated either singly with one disease or with two diseases combined was performed to check the leaf damage model. No interaction of the two diseases on photosynthesis loss was observed when they occurred simultaneously on the same leaf. In a second step, the single-leaf model was extended to the canopy scale to model the effects of the leaf rust-STB complex on the growth of a wheat crop. The model predicts the effects of disease on the growth of an affected crop relative to the growth of a healthy crop. The canopy model accounted for different contributions to photosynthetic activity of leaf layers, derived from their position in the canopy and their natural leaf senescence. Treatments differing in nitrogen fertilization, microclimatic conditions, and wheat cultivars were implemented in a field experiment to evaluate the model. The model accurately estimated the effect of disease on crop growth for each cultivar, with differences from experimental values lower than 10%, which suggests that this model is well suited to aid an understanding of disease effects on plant growth. A reduction in green leaf area was the main effect of disease in these field experiments and STB accounted for more than 70% of the reduction in plant growth. Simulations suggested that the production of rust spores may result in a loss of biomass from diseased crops and that stem photosynthesis may need to be considered in modelling diseased crop growth.
构建了一个预测小麦叶枯病（STB）和叶锈病对小麦生长影响的模型，并分两步进行评估。在叶片尺度上，通过考虑叶锈病 - STB复合体，将预测感染单一病害的小麦叶片相对光合作用的巴斯蒂安斯方法扩展到两种病害的情况，其中一种是活体营养型病害，另一种是死体营养型病害。进行了一项温室试验，对旗叶单独接种一种病害或同时接种两种病害，以检验叶片损伤模型。当两种病害同时出现在同一叶片上时，未观察到它们对光合作用损失的相互作用。在第二步中，将单叶模型扩展到冠层尺度，以模拟叶锈病 - STB复合体对小麦作物生长的影响。该模型预测病害对受影响作物生长的影响相对于健康作物生长的影响。冠层模型考虑了叶层对光合活性的不同贡献，这是由它们在冠层中的位置及其自然叶片衰老所决定的。在田间试验中实施了氮肥施用、微气候条件和小麦品种不同的处理，以评估该模型。该模型准确估计了每种品种病害对作物生长的影响，与实验值的差异低于10%，这表明该模型非常适合帮助理解病害对植物生长的影响。绿叶面积的减少是这些田间试验中病害的主要影响，叶枯病占植物生长减少量的70%以上。模拟结果表明，锈孢子的产生可能导致患病作物生物量的损失，并且在模拟患病作物生长时可能需要考虑茎光合作用。
