Genotypic Effect of Rootstock and Scion on Grafting Success and Growth of Kola (Cola nitida) Seedlings

Abstract

Kola (Cola nitida) is an important economic cash crop for many West and Central African countries. It has several medicinal uses in the pharmaceutical industries and also plays a major role in traditional marriages among Islamic communities across West and Central Africa. The crop is extensively cultivated in Nigeria and Ghana. However, it exhibit signs of total and partial sterility as well as self incompatibility when propagated from seeds in most cases. Therefore, grafting is seen as a method of choice in addressing the problem stated above. Though grafting accounts for some degree of success, there is the need to assess genotypic and physiological factors that account for high or low grafting success. Genetic and physiological factors (such as rootstock age) affecting grafting success and growth in kola (C. nitida) were investigated in two separate experiments. In experiment I720 kola seedlings were raised from unselected kola nuts and sown at two monthly intervals. Four groups of seedlings (180/group) i.e. 6, 8, 10 and 12 months old were thus produced. Three different scions (A1, A12 and JB1) measuring (5 -10 cm) were grafted onto the four age groups of rootstocks, namely, 6, 8, 10 and 12 months. Experiment II consisted of 540 seedlings raised from three main crosses (JX1/9 × JX1/11 * B1/142 × B1/151, JX1/9 × JX1/11 * B2/177 × B2/156 and JX1/9 × JX1/11 * GX1/46 × GX1/53). Grafting was done after six months using the same set of scions as described in experiment I. Experimental design used was 3 × 4 and 3 × 3 factorial designs in completely randomised design with three replicates for experiment I and II respectively. The fixed effects were the different genotype and age of rootstock at grafting whilst the response variable was the percentage of successful grafting two months as well as growth at six monthly intervals. Results from the study showed that grafting onto 6 months old stocks gave the highest percentage success and growth of grafts followed by 8, 10 and 12 months old rootstock in that order in both trial years. The study revealed also a significant rootstock and scion interaction (P < 0.05). We conclude that successful grafting in kola depends on rootstock genotype such as A. M. Dadzie et al. 3874 JX1/9 × JX1/11 * GX1/46 × GX1/53 and has been proven suitable for use in future kola propagation studies. Nonetheless, suitable rootstock with high grafting success does not translate into vigorous scion growth.

Rootstock age and grafting season affect graft success and plant growth of papaya (Carica papaya L.) in greenhouse

“…Results have also shown that younger rather than old rootstocks obtained a higher percentage of graft success; the highest rate occurred when grafted with 1-mo-old rootstocks. This coincides with Islam et al (2004) working in mango and Dadzie et al (2014) working in kola. Using young rootstocks gave the best results for scion height and number of leaves.…”

Successful grafting elite cocoa clones (Theobroma cacao L.) as a function of the age of rootstock

“…Besides, according to Refs. [ 44 , 45 ], it is consistent that rootstock age and scion type play a critical part in reaching grafting success. Grafting onto 4-month-old rootstocks could save cost compared to 2 and 3-month-old ones.…”

Vegetative propagation of cocoa (Theobroma cacao) by grafting: Aptitude of grafting on four clones

“…However, Hibbert-Frey et al ( 2010) pointed out that water availability is important but not a primary factor for graft success, specifying that the physiological condition of both the scions and rootstocks could also affect graft success. Dadzie et al (2014) observed optimum grafting success in Cola nitida with six months old rootstock, with a decreasing rate of success as the rootstock became older. Apart from rootstock age, the latter authors also indicated that success depends on the compatibility of Although clone 3 had the highest value for the budding rate and number of leaves (Figure 2), it was not significantly different from clone 4 (Table 1).…”