ISHS Acta Horticulturae 738: International Symposium on Biotechnology of Temperate Fruit Crops and Tropical Species
CYTOKININ HABITUATION FOR AUTONOMOUS SHOOT INITIATION IN PAWPAW (ASIMINA TRILOBA) |
| Authors: | R.L. Geneve, S.T. Kester, K.W. Pomper |
| Keywords: | Asimina, shoot formation, autotrophic, tissue culture, micropropagation |
| Abstract:
Pawpaw is native to Eastern North America and shows good potential as a tree fruit crop. Micropropagation could provide a clonal propagation method for plant production and germplasm preservation. Once established, pawpaw cultures typically produce many shoot-bud clusters that do not readily elongate. Shoot-bud cultures that had been maintained on a BA (8.9 µM) + NAA (2.3 µM) medium for over five years showed evidence of cytokinin habituation. Single shoot-buds (1.5 cm) moved to a media with or without plant growth regulators (PGR) continued to initiate new shoots at a similar rate (~ 5 to 8 shoots per culture). Shoots on PGR medium failed to elongate shoots greater than 2 cm compared to approximately 12% for those on PGR-free medium. Single shoot-buds subcultured three times to PGR-free medium continued to initiate between 5 to 7 shoot-buds per culture and shoot elongation remained at approximately 16%. This sensitivity to cytokinin and apparent carryover effect may in part explain the recalcitrant nature of pawpaw microcuttings to rooting. | |
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