primary root; main root
Botanical term for the first root that develops from a seed, forming the central axis of the root system.
The primary root is the first root that grows from the seed.
In many plants, the primary root becomes the taproot.
Taproot; often the same as the primary root in many plants, but 主根 emphasizes the main root of a mature plant.
Compound of 一次 (いちじ, 'primary, first') and 根 (こん, 'root'). A straightforward technical term in botany.