(A)biotic stress in Ilex crenata: solving problems of soil pH and black root rot

Plants can be subject to abiotic stress such as heat, salinity and pH stress.
The presence of abiotic stress can profoundly affect the plant’s response to the biotic stresses caused by pests or pathogens.
This relation is present in Ilex crenata or box-leaved holly, an evergreen shrub often used in topiary and hedges.
When planted in alkaline soils, the plant experiences abiotic stress in the form of a nutrient deficiency.
Alkaline soils also provide good conditions for the soil fungus Berkeleyomyces basicola [prev. Thielaviopsis basicola]. This combination favors infection of I. crenata by B. basicola, adding biotic stress to the already-present abiotic stress.
Plant breeding can help to improve pH tolerance as well as disease resistance.
Up to now, new box-leaved holly cultivars have largely been the result of lucky findings.
Creation of cultivars that tolerate these abiotic and biotic stressors will require a targeted breeding approach.
The aim of the present study was to support breeding efforts by developing standardized bioassays and choosing relevant parameters to evaluate the response of different genotypes to these (a)biotic stressors separately and in combination.
Specifically, the use of the parameters shoot and root weight, chlorophyll fluorescence, and disease severity are discussed.

V International Symposium on Woody Ornamentals of the Temperate Zone

E. Geukens, K. Heungens, J. Van Huylenbroeck, E. Smolders, L. Leus

alkalinity, Berkeleyomyces basicola, chlorophyll fluorescence, Japanese holly, plant stress

https://doi.org/10.17660/ActaHortic.2025.1434.29