Effects of cutting position of rose rootstock cultivars on rooting and its relationship with mineral nutrient content and endogenous carbohydrates

- Cutting position affected rooting ability and growth of rose rootstocks.
- The endogenous mineral nutrient and carbohydrate contents varied with the cutting position of 'Natal briar' and 'Rosa progress'.
- Nitrogen and zinc positively correlated to root number and sucrose content of stem positions correlated to root number.
- The rootstocks 'Natal briar' and 'Rosa progress' had varied concentrations of sugars in their stem cuttings.

The stem cuttings for propagating rose rootstocks are usually obtained from the shoots on the mother stock irrespective of the position. However, adventitious root formation may be influenced by the cutting position. We therefore determined the effects of cutting position of rose rootstocks on rooting and its relationship with endogenous mineral nutrient (Nitrogen, zinc, manganese and iron) and carbohydrate (glucose, fructose, sucrose and total soluble sugars) contents. Cuttings were obtained from three positions; top, middle and bottom, from two rootstocks, 'Rosa progress' and 'Natal briar' and planted under greenhouse conditions in a randomized complete block design replicated 3 times. Carbohydrates and mineral nutrient content in the cuttings were determined at 0, 3 and 7 days after planting (DAP). The root number, total root length, shoot height, leaf number and percentage survival increased acropetally. The zinc and manganese content was higher in top position of 'Natal briar' and middle position in 'Rosa progress' than in bottom position cuttings of both rootstocks and this positively correlated to root number in both rootstocks. The nitrogen content increased acropetally in 'Natal briar' and was positively correlated to root number. Top position cuttings recorded higher sucrose content in both rootstocks. There was a positive correlation between sucrose content and the number of roots at 7 DAP in 'Natal briar' and in 'Rosa progress' at 3 and 7 DAP. There was also a positive correlation between root number and total sugar at 0 and 7 DAP in 'Rosa progress' and 7 DAP in 'Natal briar'. The results of this study demonstrate the importance of endogenous mineral nutrient and soluble sugar contents of the stem cutting for the rooting process in Rosa hybrida rootstocks and apical cuttings should be used to multiply the two rootstocks.