Effects of Morphological Characteristics, Nutritional Status and Light on the Scale Propagation of Lilium

Scaling is the most commonly used technique to artificially propagate lilies. Scales from different positions of the donor bulb vary in regeneration efficiency; however, the mechanism underlying bulblet formation remains unclear. To investigate the relationship between scale morphological characteristics, initial nutrient status and bulblet regeneration capacities during scale propagation of Lilium, we performed comprehensive morphological and correlation analyses using scales from three lily cultivars. Principal component analysis clearly distinguished middle scale (MS) from outer scale (OS) by morphological characteristics alone. Morphological results indicated that MS and OS differ significantly in terms of scale width, facial area, basal area, volume, length-to-width ratio and width-to-thickness ratio. Correlation analysis showed that scale width was significantly positively correlated with both the quantity and quality of regenerated bulblets. Among the cultivars, starch and soluble sugars accounted for 50-80% of scale DW. And a higher initial ratio of sucrose to starch in scales was more conducive to the bulblets formation. Although light had no effect on the incidence of bulblets, the formation of bulblets was positively enhanced, and better morphological consistency was obtained. This present study achieved a comprehensive morphological and nutritional analysis focused on bulblet formation capacities of scales from different positions of lily bulbs via scaling propagation, laying a foundation for future molecular studies on bulblet formation.

Automated summary

Comprehensive morphological and correlation analyses were performed on scales from three lily cultivars to investigate the relationship between scale morphological characteristics, initial nutrient status, and bulblet regeneration capacities. The results showed significant morphological differences between middle scale (MS) and outer scale (OS), and scale width was positively correlated with the quantity and quality of regenerated bulblets. Starch and soluble sugars accounted for a large portion of scale dry weight, and a higher initial ratio of sucrose to starch promoted bulblet formation.