1. The root system of a plant, especially a woody plant or tree, onto which another variety is grafted
The apple tree was grafted onto a dwarfing rootstock to control its size.
A maçã foi enxertada em um porta-enxerto anão para controlar seu tamanho.
2. The base plant or root system used as the foundation in grafting operations
A strong rootstock ensures the grafted plant will thrive in poor soil conditions.
Um porta-enxerto resistente garante que a planta enxertada prospere em condições de solo pobre.
3. The underground stem or root structure of a perennial plant from which new growth emerges
The rootstock of the rose survived the harsh winter and sprouted new canes in spring.
O porta-enxerto da rosa sobreviveu ao rigoroso inverno e brotou novos ramos na primavera.