Figure 1.

Seed selection, sterilization, and germination strategies for Castilleja affinis

(A) Mature C. affinis seed pods with extracted seeds. Dark brown to blackish-brown seeds exhibit higher viability than lighter brown seeds. Scale bar: 1 cm.

(B) Bright-field microscopy image of dark brown C. affinis seeds showing their distinct triangular shape.

(C) Preparation for sowing C. affinis seeds on F-medium plates for use in plant-plant interaction assays. Imbibed seeds are handled using sterilized tools and placed on solidified F-medium in square plates for germination.

(D) Sowing of C. affinis seeds on F-medium plates, arranged in rows to ensure even spacing and optimal seedling development for subsequent plant-plant interaction experiments.

(E) Initial setup for hormone treatment assays. C. affinis seeds are placed on a sterile Whatman filter paper inside a Petri dish.

(F) C. affinis seeds distributed on Whatman filter paper before stratification at 4°C. These seeds will later be used for hormone treatment assays.