“Effect of leaf rust (Puccinia triticina) on photosynthesis and related processes of leaves in wheat crops grown at two contrasting sites and with different nitrogen levels

CARRETERO R; BANCAL MARIE ODILE; MIRALLES DJ

EUROPEAN JOURNAL OF AGRONOMY

ELSEVIER SCIENCE BV

Lugar: Amsterdam Holanda; Año: 2011 vol. 1 p. 237 - 246

1161-0301

Leaf rust is one of the main diseases affecting wheat yield production. 11 Considering the physiological variables that determine yield, diseases could affect 12 radiation capture and/or radiation use efficiency. Reductions in radiation use efficiency 13 may be mediated through effects on photosynthesis rate and related variables (i.e: dark 14 respiration rate, stomatal conductance or photosynthesis events per se). The aim of 15 this study was to analyze the effects of leaf rust on wheat leaves photosynthesis rate 16 and to understand which processes determining photosynthesis are affected by this 17 pathogen. Gas exchange measurements were taken on flag leaves with various rust 18 severity levels in experiments carried out on two locations which included different 19 nitrogen fertilization rates and sowing dates. Leaf rust reduced net photosynthesis rate 20 at light saturation through reductions in gross photosynthesis (average reduction: 6.1 μmol CO2 m-2 green area s-121 ) rather than through increases in dark respiration rate (average increase: 0.7 μmol CO2 m-2 green area s-122 ). Changes in leaf nitrogen 23 concentration did not modify the effects of leaf rust on net photosynthesis rate.