Spike architecture traits associated with type II resistance to fusarium head blight in bread wheat

Fusarium head blight (FHB) remains a devastating disease in bread wheat (Triticum aestivum L.). Genetic resistance to FHB is complex; aside from active physiological resistance, plant developmental and morphological traits indirectly affect disease progression and provide a passive resistance mechanism. Here, the relationship between FHB Type II resistance and spike architecture traits was evaluated in a recombinant inbred line (RIL) population of bread wheat in field experiments during two crop seasons under a completely randomized block design with two replications. Point inoculation was carried out at anthesis of each RIL. Disease severity at 21 days post inoculation (dpi), area under the disease progress curve (AUDPC) comprising severity measurements at 12, 17 and 21 dpi, rachis length, spike density, number of spikelets per spike, number of florets per spike and number of florets per spikelet were determined. The population showed significant variation for all traits. Heritability was moderate-high for FHB severity (0.69) and AUDPC (0.63) and high for spike architecture traits (0.74–0.92). FHB severity at 21 dpi and AUDPC were significantly associated with number of florets per spike [r = 0.38 (P < 0.001) and r = 0.31 (P < 0.01) respectively] and with the number of florets per spikelet [r = 0.28 (P < 0.01) and r = 0.27 (P < 0.05) respectively], reflecting a greater spread of the fungus in spikes with higher floret number. These results suggest that the number of florets per spike and per spikelet should be considered in FHB resistance breeding efforts, because selection of lines with higher number of florets could lead to a correlated selection response towards increased FHB levels under field conditions.EEA BalcarceFil: Franco, María Fiorella. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Unidad Integrada Balcarce. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Franco, María Fiorella. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Lori, G. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires; Argentina.Fil: Lori, G. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; Argentina.Fil: Cendoya, María Gabriela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Unidad Integrada Balcarce. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Alonso, María Pía. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Unidad Integrada Balcarce. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Alonso, María Pía. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Panelo, Juan Sebastián. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Unidad Integrada Balcarce. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Panelo, Juan Sebastián. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires; Argentina.Fil: Malbrán, I. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires; Argentina.Fil: Malbrán, I. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; Argentina.Fil: Mirabella. Nadia Estefania. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Unidad Integrada Balcarce. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Pontaroli, Ana Clara. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Unidad Integrada Balcarce. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Pontaroli, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Induction of tolerance to Fusarium head blight

Fusarium head blight (FHB), caused by Fusarium graminerarum, is a very important wheat disease causing remarkable economical damage in Argentina. Because only a few resistance sources are available, we tested synthetic hexaploids as a donor for FHB resistance several years ago. Several lines showed induced resistance against FHB after a phytohormone treatment. In this study, two novel lines (L and M) and a comercial cultivar (ACA 315) were tested in twodifferent localities (La Plata and Tres Arroyos) during three years. A split-plot design was used in order to compare the responses to the following hormone treatments: salicilic acid, jasmonic acid, giberellic acid, a solution with a strain of Pseudomonas fluorescens, or water (control), which were sprayed at anthesis. Twenty-four hours later, half of the plots of each pretreatment of each genotype were inoculated. Spikes were harvested manually, and the number of total grain, damaged kernels, and 1,000-kernel weight were recorded. Pretreatment with gibeerellic acid increased the total grain in lines L, M, and ACA315 with and without inoculation with F. graminearum compared to the controls and the rest of the treatments. Jasmonic acid induced fewer damaged kernels in lines L and M. The commercial cultivar did not show any differences between treatments. The treatment with P. fluorescens induced the highest levels of tolerance in both experimental lines with the lower values of damaged kernels and with a higher 1,000-kernel weight. These results were similar in both localities in the last two years. The elicitation of SAR in the experimental lines increased the tolerance to FHB.Fil: Börner, A.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Agacka Mołdoch, M.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Alomari, D. Z.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Cardelli, M.G.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Castro, A.M.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Chesnokov, Yu. V.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Chistyakova, A. K.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Dell’ Arciprete, M.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Dietz, J. I.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: K. Eggert,. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Fauzia, G. S.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Giménez Gerard, D.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Jończyk, K.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Lohwasser, U.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Lori, G.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Malbrán, I.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Morozova, E. V.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Muqaddasi, Q. H.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Nagel, M.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Osipova, S. V.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Pardi, H. M.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Perelló, A. E.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Perello, L.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Permyakov, A. V.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Permyakova, M. D.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Pshenichnikova, T. A.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Rehman Arif, M. A.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Röder, M. S.. Leibniz Institute of Plant Genetics and Crop Plant Research; AlemaniaFil: Saldua, Vilma Luciana. Leibniz Institute of Plant Genetics and Crop Plant Research; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Yanniccari, Marcos Ezequiel. Leibniz Institute of Plant Genetics and Crop Plant Research; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal