IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
Does radiation interception or radiation use efficiency limit the growth of wheat inoculated with tan spot or leaf rust?
Autor/es:
SCHIERENBECK MATÍAS; SIMÓN MARÍA ROSA; MIRALLES DANIEL JULIO; FLEITAS MARÍA CONSTANZA
Revista:
FIELD CROPS RESEARCH
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2016 vol. 199 p. 65 - 76
ISSN:
0378-4290
Resumen:
Abstract: Tan spot [Pyrenophora tritici-repentis (Died.) Drechs.,anamorph Drechslera tritici-repentis) (Died.) Shoem.] and leaf rust(Puccinia triticina Eriks) are major diseases worldwide and some of themain biotic causes of yield and quality reduction in wheat (Triticumaestivum L.). Although wheat crop losses due to foliar diseases havealready been studied based on an ecophysiological approach, none of thesestudies analyzed the independent effects of foliar pathogens withdifferent nutritional habits. The aim of the present study was todetermine the independent effects of (i) Py. tritici-repentis(necrothroph) and (ii) Puccinia triticina (biotroph) on the physiologicalcomponents of biomass production: absorbed photosynthetic activeradiation (APAR), intercepted radiation use efficiency (RUEint) andabsorbed radiation use efficiency (RUEabs) in a wide range of Argentinecommercial bread wheat cultivars growing in two field environments. Fieldexperiments were carried out during two consecutive years combining alarge range of wheat bread commercial cultivars and two levels ofinoculation to promote infection of Tan spot and Leaf rust diseases,including a control without inoculation. Treatments were arranged in anexperimental split-split plot design with three replications, where themain plots were both diseases, subplots corresponded to inoculationtreatments 1- Without inoculation (WI), 2- Low concentration of inoculumof each disease (LC), 3- High concentration of inoculum of each disease(HC) and ten Argentine bread wheat commercial cultivars were the subsubplots.Area under disease progress (AUDPC), area under percentage ofnon-green leaf area (AU%NGLA), crop growth rate (CGR) and healthy areaduration (HAD) were calculated. Green leaf area index (GLAI), abovegroundbiomass (AGB), APAR and RUE were measured at three different crop stages(GS39, GS61 and GS82). Increases of inoculum concentration of foliardiseases decreased AGB between 7.8-20.2% mainly explained by reductionsin HAD and decreases on APAR by 13.8-18.3% with higher reductions whenthe crop was inoculated with Py. tritici-repentis than with P. triticina.Although both diseases reduced the physiological components ofaccumulated biomass related to radiation interception (APAR), RUEint (-23%), RUEabs (-11.2%) and CGR (-28.9%) were more reduced, respect to WI,when plants were inoculated with P.triticina compared to Pyrenophoratritici-repentis. The differential responses in RUE could be associatedwith the nutritional habit of this pathogen that reduces leaf nitrogenconcentration, enhance assimilates consume by leaf respiration andthereby diminishing radiation use efficiency.