The role of sterile plant lines in the management of invasive and allergenic plants in urban environments

Urbanization is accelerating worldwide, intensifying ecological and public health challenges linked to invasive and allergenic plant species. Sterile ornamental cultivars have been proposed as a promising response, offering the potential to reduce allergenic pollen loads and limit invasive spread. However their deployment in urban green infrastructure cannot be assessed solely on biological grounds; it requires a broader understanding of ecological trade-offs, regulatory frameworks, public acceptance, and long-term economic feasibility. Ecologically, sterility may reduce pollen and seed production, but it can also simultaneously limit floral resources for pollinators, decrease genetic diversity in nursery stocks, and even risk fertility reversion through hybridization or mutation. These trade-offs highlight the need for diversified planting schemes that combine sterile lines with pollinator-supporting species, as well as continuous genetic and ecological monitoring. From a regulatory standpoint, heterogeneity across regions complicates implementation, with some countries treating sterility as a biosafety advantage, while others impose GMO-related restrictions that delay commercialization. Public acceptance further shapes outcomes: while residents may welcome reductions in nuisance fruiting and allergens, cultural attachment to fruiting trees and skepticism toward biotechnological breeding can hinder the adoption of these measure. Effective communication and demonstration projects are therefore crucial for building trust and highlighting both benefits and limitations. Economic considerations also play a decisive role: although the propagation of sterile lines often entails higher initial costs, potential long-term savings in maintenance, allergen management, and invasive species control can justify the investment if supported by reliable cost–benefit analyses. Taken together, sterility should be regarded not as a universal solution but as a targeted instrument within integrated urban greening strategies. Its success depends on aligning ecological performance with regulatory clarity, public trust, and economic justification, ensuring that sterile cultivars contribute to healthier, more resilient, and socially meaningful urban landscapes.