Influence of propagation temperature, photosynthetic photon flux density, auxin treatment and cutting position on root formation, axillary bud growth and shoot development in Schlumbergera ‘Russian Dancer’

Abstract

Summary The effects of propagation soil temperature and photosynthetic photon flux density (PPFD), indole-3-butyric acid (IBA) concentration, and cutting position on root formation, axillary bud growth, and further growth were investigated in Schlumbergera ‘Russian Dancer’. Temperatures between 21.3ºC and 24.7ºC were optimal for root formation, whereas increasing temperature promoted axillary bud growth (onset of new phylloclade growth). At temperatures below 24.7ºC, root formation and axillary bud growth occurred more or less simultaneously, whereas at higher temperatures axillary bud growth occurred before roots were visible. Temperature also affected the number of phylloclades on the second and third levels of stem segments produced after propagation. On increasing PPFD from 46 to 72 µmol m–2 s–1 during propagation, time to axillary bud growth was reduced by 15%, and more phylloclades were produced at high PPFD combined with high temperature. Rooting ability and axillary bud growth were affected by cutting position on the stock plants, indicating the presence of topophysis in Schlumbergera. Time to visible roots and number of new phylloclades decreased basipetally with the original position of the cutting by approximately 25%, whereas time to axillary bud growth increased basipetally by 30%. Survival of cuttings receiving IBA at 10–5–10–3 M was superior. IBA at 10–3 M resulted in the shortest time to visible rooting. At increasing IBA concentration, time to axillary bud growth gradually increased and fewer phylloclades were produced. Concentrations of 10–2 and 10–1 M IBA had negative effects on all measured characters. The results are discussed in relation to possible roles of auxins and cytokinins.