Wheat leaf photosynthesis loss due to leaf rust, with respect to lesion development and leaf nitrogen status

• Published in: The New phytologist Vol. 165; no. 1; pp. 227 - 241
• Main Authors: Robert, C, Bancal, M.O, Ney, B, Lannou, C
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science 2005; Blackwell Science Ltd; Blackwell
• Subjects: Basidiomycota - physiology; Bastiaans' Model; Biological and medical sciences; damages; Disease models; Epidemiology; fertilizer application; Fertilizers; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; leaf nitrogen (N); leaf photosynthesis; leaf rust (Puccinia triticina); Leaves; lesion development; Lesions; lesions (plant); modelling; Nitrogen; Nitrogen - physiology; nitrogen content; NPK fertilizers; Pathology, epidemiology, host-fungus relationships. Damages, economic importance; Photosynthesis; Photosynthesis - physiology; Phytopathology. Animal pests. Plant and forest protection; Plant diseases; Plant Diseases - microbiology; Plant Leaves - microbiology; Plant Leaves - physiology; plant pathogenic fungi; Plants; Puccinia recondita; Puccinia triticina; quantitative analysis; rust diseases; Rust fungi; Sporulation; Triticum - microbiology; Triticum - physiology; Triticum aestivum; wheat; Puccinia recondita f. tritici; Monocotyledones; Plant pathogen; Fertilization; damages; Basidiomycetes; Host agent relation; leaf nitrogen (N); Plant leaf; leaf photosynthesis; modelling; Cereal crop; Fungi; lesion development; Gramineae; Sporulation; Angiospermae; Spermatophyta; Models; Photosynthesis; quantitative analysis; leaf rust (Puccinia triticina); Triticum aestivum; Thallophyta
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2004.01237.x

• In wheat (Triticum aestivum cv. Soissons) plants grown under three different fertilisation treatments, we quantified the effect of leaf rust (Puccinia triticina) on flag leaf photosynthesis during the whole sporulation period. • Bastiaans' model: Y = (1-x)β was used to characterize the relationship between relative leaf photosynthesis (Y) and disease severity (x). The evolution of the different types of symptoms induced by the pathogen (sporulating, chlorotic and necrosed tissues) was evaluated using image analysis. • The β-values varied from 2 to 11, 1.4-2, and 0.8-1 during the sporulation period, when considering the proportion of sporulating, sporulating + necrotic, and total diseased area, respectively. Leaf nitrogen (N) content did not change the effect of the disease on host photosynthesis. • We concluded that leaf rust has no global effect on the photosynthesis of the symptomless parts of the leaves and that the large range in the quantification of leaf rust effect on the host, which is found in the literature, can be accounted for by considering the different symptom types. We discuss how our results could improve disease assessments and damage prediction in a wheat crop.