• The source supply affects the AM regeneration cycle and bulblet formation. • The middle part of the scale base has the highest probability for bulblet occurring. • Bulblet formation locations are highly correlated with vascular bundles of scales. • Sucrose is the main form sugars transported in Lilium. Lily ( Lilium spp.) is one of the most important bulbous flowers and occupies a crucial position in cut flower production worldwide. In the present study, an ex vivo bulblet formation routine was established using large-scale aerial culture for further exploration of the source-sink relationship. Our results revealed that sucrose is the main form of sugar as photosynthetic products transporting through phloem tissues in Lilium . Scales belong to the modification of leaves, bulblet regeneration on the scale base depends on nutrients transported from source to sink organs, and photoperiod is a dominant factor. Furthermore, we established a prediction model based on large-scale phenome analysis for precise sampling during bulblet formation as well as emphasized the irreplaceable role of vascular bundles. The bulblet regeneration cycle was further divided to provide a reference for subsequent mechanism studies on the source-sink relations.
Kang et al. (Sun,) studied this question.