CYTOKININ HABITUATION FOR AUTONOMOUS SHOOT INITIATION IN PAWPAW (ASIMINA TRILOBA)

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.

International Symposium on Biotechnology of Temperate Fruit Crops and Tropical Species

R.L. Geneve, S.T. Kester, K.W. Pomper

Asimina, shoot formation, autotrophic, tissue culture, micropropagation

https://doi.org/10.17660/ActaHortic.2007.738.44