The role of light and CO₂ in optimising the conditions for shoot proliferation of <i>Actinidia deliciosa</i> in vitro

Abstract

Proliferating cultures of Actinidia deliciosa A. Chev., C. F. Liang and A. R. Ferguson cv. Tomuri (♂) were grown under photosynthetic photon flux density (PPFD) rates ranging from 30 to 250 μmol m −2 s −1 in order to determine certain physiological parameters in vitro: CO 2 evolution, photosynthesis at three CO 2 atmospheric concentrations (330, 1450 and 4500 μl l −1 ), fresh and dry matter accumulation and proliferation rate. A proportional response in dry weight, dry/fresh weight ratios and PPFD was found. The proliferation rate increased up to 120 μmol m −2 s −1 but decreased at higher rates. At the highest PPFD, the CO 2 released from cultures and accumulated in the vessels reached 200 μl l −1 of; at the lowest rate the CO 2 concentration reached 10500 μl l −1 after 28 days of culture. The photosynthetic rate at 1450 and 4500 μl l −1 of CO 2 was nearly 4 times higher than at the lowest concentration tested.