Micrografting methods with Torreya grandis ‘Merrillii’

Abstract

To confirm the best micrografting method and improve the propagation coefficient of Torreya grandis ‘Merrillii’, seedlings which were not lignified and sprigs with no T. grandis ‘Merrillii’ terminal bud were prepared for an experiment to study dynamic germination changes, survival rates, and growth conditions. Different micrografting techniques with scions having 2, 4, and 6 pieces of leaves as well as scions with and without terminal buds were used. The micrografting methods design with treatments of cleft grafting, drill grafting and side grafting and 3 replications. Every treatment was randomly selected 30 seedlings to statistics and analyze. Results showed that cleft grafting of T. grandis ‘Merrillii’ seedlings had more advantages. The scions germinated after being grafted 15 d, and the grafting survival rate was high (89.7%) which was significant difference under the LSD significance test method with the other two micrografting methods at P=0.05. Also, the cleft grafted seedlings which growth of new shoots was greater, but the coarseness of growth, the number of new branches and stubble, and the number of new crops and leaves showed no significance differences at P=0.05. This study showed that micrografting seedlings of scions without terminal buds were more likely to survive in the short term, but in the long run, cleft grafting with scions removed on terminal buds and with 4 to 6 pieces of leaves was the most suitable for growth of T. grandis ‘Merrillii’.