Canopy and Ear Traits Associated With Avoidance of Fusarium Head Blight in Wheat

Abstract

Doubled haploid and elite wheat genotypes were ground inoculated in three field experiments and head spray inoculated in two glasshouse experiments, using mixed Fusarium and Microdochium species, to identify crop canopy and ear traits associated with Fusarium head blight (FHB) disease. In all experiments, flag leaf length and tiller number were consistently identified as the most significant canopy traits contributing to progression of FHB caused by Fusarium graminearum, F. culmorum, and F. avenaceum. The influence of ear traits was greater for F. poae that may possess more diverse routes for transmission and spread. Consistently, spikelet density was associated with increased disease severity in the field. F. graminearum, F. culmorum, and F. langsethiae were the main mycotoxin producers and their respective toxins were significantly related to fungal biomass and number of spikelets per ear. Genotypes with lower tiller numbers, shorter flag leaves and less dense ears may be able to avoid FHB disease caused by F. graminearum, F. culmorum, F. avenaceum, or Microdochium species however selection for these canopy and ear architectural traits to enable disease avoidance in wheat is likely to result in a potential trade-off with grain yield and therefore only moderately advantageous in susceptible genotypes.

Resistance of Winter Spelt Wheat [Triticum aestivum subsp. spelta (L.) Thell.] to Fusarium Head Blight

“…The authors therefore conclude a direct or indirect effect on FHB severity of plant height per se via morphological and structural differences (e.g., reduced peduncle length) and thereby changes in the canopy microclimate. Similar conclusions were reached by Jones et al (2018) and Tessmann and Van Sanford (2019) . In the present spelt diversity panel, no knowledge about the presence of specific Rht genes is available.…”

Breeding for Fusarium head blight resistance in wheat—Progress and challenges

“…Notably, an advantage of taller plants was also found after spray inoculation, where spores are applied from top. Plant height potentially influences microclimate such as relative humidity, leaf wetness duration and temperature at spike height as shorter plants are more affected by soil humidity and dew and a denser canopy structure may lead to reduced air circulation (Buerstmayr & Buerstmayr, ; Hilton, Jenkinson, Hollins, & Parry, ; Jones, et al, ). High humidity and temperature promote infection and disease development and may thus lead to an increased disease pressure on the shorter plants.…”

Methodical Considerations and Resistance Evaluation against F. graminearum and F. culmorum Head Blight in Wheat. The Influence of Mixture of Isolates on Aggressiveness and Resistance Expression

“…The Fusarium resistance testing is a very sensitive experimental system. The pathologically uncontrolled mixing and conidium concentration adjusting cannot secure the stable high aggressiveness needed to receive high differentiation of the genotypes [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 ]. Mixing and conidium concentration adjusting, which are applied without controlling by plant pathological methods, cannot secure the stable h...…”