Genotypic Variability in Root Morphological Traits in Canola (Brassica napus L.) at the Seedling Stage

Canola (Brassica napus L.) is a vital oilseed crop, but its sustainable production is increasingly challenged by climate change. Characterizing genotypic variation in root morphological traits in canola provides a basis for breeding new varieties with root traits that enhance soil nutrient uptake, water use efficiency, and adaptation to stress. This study evaluated genotypic variation in 25 root morphological traits and 2 shoot traits across 173 canola genotypes using a semi-hydroponic phenotyping platform under controlled conditions. Large genotypic variation was observed in the majority of root traits. Nineteen traits with a coefficient of variation greater than 0.3 were selected for further analysis. Principal component analysis identified five components with eigenvalues > 1, collectively accounting for 87.9% of the total variability. Hierarchical cluster analysis classified the 173 genotypes into five distinct clusters. The broad genotypic variations in root morphological traits among genotypes offer significant potential for future research aimed at identifying molecular markers and genes associated with key morphological traits. This study provides a strong foundation for the genetic improvement of canola to enhance resource-use efficiency and tolerance to environmental stresses, such as drought and heat stress.