Preliminary studies on in vivo germination of Actinidia arguta and Actinidia chinensis
The expansion of the kiwifruit industry in South Africa has led to increasing demand in the new improved species, Actinidia arguta and Actinidia chinensis, with smaller and sweeter fruits than the commonly grown Actinidia deliciosa. Seed dormancy had been an obstacle in the successful seedling establishment of the two Actinidia species thus, the effect of gibberellic acid (GA3) and cold stratification (CS) on in vivo seed germination was studied. In the GA3 experiment, non-stratified seeds were imbibed in dH2O (control) and GA3 solutions (500, 1000, 2000 and 2500 ppm) for 24 h at ambient temperature. For the CS experiment, seeds of both species were stratified on moist filter paper at 4°C for 14, 28, 42 and 56 days, while seeds kept at ambient temperature served as a control. Seeds from different GA3 and CS treatments were sown in seedling trays filled with moistened vermiculite and kept under controlled conditions. Data on seedling performance variables, namely, germination percentage (GP), mean germination time (MGT), germination rate (GR) and germination index (GI) were subjected to ANOVA and then lines of the best fit. Imbibing kiwifruit seeds for 24 h in solutions of different GA3 concentrations resulted in no germination of A. arguta seeds and a very poor germination (1%) of A. chinensis seeds. In the cold stratified seeds, treatment effects were significant (p≤0.05) in A. chinensis, except for A. arguta seeds. In A. chinensis, the optimum CS duration and performance values were 37 days and 16% for GP, 34 and 15 days for MGT, 33 days and 0.04 seedling day-1 for GR and 39 days and 0.13 seedling day-1 for GI, respectively. Results of this study suggested that GA3 had no positive effect, whereas CS had a promising effect on in vivo seed germination in both Actinidia species.
Sekhukhune, M.K., Maila, M.Y., Nikolova, R.V. and Mphosi, M.S. (2018). Preliminary studies on in vivo germination of Actinidia arguta and Actinidia chinensis. Acta Hortic. 1204, 123-132
cold stratification, in vivo, kiwi berries, physiological dormancy, seed germination