Abstract: To investigate the effects of different seed collection orientations on the seed quality,root traits,and seedling phenotypic traits of Mytilaria laosensis,identify the optimal seed collection orientation,and elucidate the regulatory pattern of seed collection orientation on seedling growth,this study used seedlings grown from seeds collected at different canopy orientations as research materials.We measured seedling root and phenotypic traits,and adopted analysis of variance and correlation analysis to quantify the orientation effect and the correlation between root and shoot growth.The results show that seed collection orientation significantly affects seed quality and seedling growth. The 1000-seed weight and seed length of the southern orientation were 79.04 g and 10.74 mm,respectively,which are 61.04% and 20.40% higher than those of the poorest orientation.The seedling height,ground diameter,total root length and root volume of the southern orientation were 50.37 cm,4.32 mm,856.39 cm and 3.53 cm³,respectively,which were 30.16%,77.05%,483.77% and 279.57% higher than those of the poorest orientation,and the differences were all significant. Correlation analysis indicates a significant association between root and shoot traits of Mytilaria laosensis seedlings.This study confirms that the southern canopy orientation was the optimal position for collecting high-quality Mytilaria laosensis seeds.Variations in seed quality caused by different seed collection orientations were the key factors driving seedling growth differences.The findings provide theoretical support and technical references for the selective breeding and high-quality seedling cultivation of Mytilaria laosensis.