RT Journal Article
SR Electronic
T1 Improved control of Septoria tritici blotch in durum wheat using cultivar mixtures
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 664078
DO 10.1101/664078
A1 S. Ben M’Barek
A1 P. Karisto
A1 M. Fakhfakh
A1 H. Kouki
A1 A. Mikaberidze
A1 A. Yahyaoui
YR 2019
UL http://biorxiv.org/content/early/2019/06/10/664078.abstract
AB Mixtures of cultivars with contrasting levels of disease resistance are capable of suppressing infectious diseases in wheat, as demonstrated in numerous field experiments. Most studies focused on airborne pathogens in bread wheat, while splash-dispersed pathogens have received less attention, and no studies have been conducted in durum wheat. We conducted a field experiment in Tunisia, a major durum wheat producer in the Mediterranean region, to evaluate the performance of cultivar mixtures in controlling the polycyclic, splash-dispersed disease Septoria tritici blotch (STB) in durum wheat. To measure STB severity, we used a novel, high-throughput method based on digital analysis of images captured from 1284 infected leaves collected from 42 experimental plots. This method allowed us to quantify pathogen reproduction on wheat leaves and to acquire a large dataset that exceeds previous studies with respect to accuracy and statistical power. Our analyses show that introducing only 25% of a disease-resistant cultivar into a pure stand of a susceptible cultivar provides a substantial reduction in disease -- down to the level of resistant pure stands -- and a corresponding mitigation of yield loss. However, adding a second resistant cultivar to the mixture did not further improve disease control, contrary to predictions of epidemiological theory. Susceptible cultivars are often agronomically superior to resistant cultivars. Hence, if mixtures with only a moderate proportion of the resistant cultivar provide similar degree of disease control as resistant pure stands, as our analysis indicates, such mixtures are more likely to be accepted by growers.