LIGHT QUALITY AND QUANTITY: THEIR EFFECTS ON IN VITRO GROWTH AND DEVELOPMENT OF TWO AUSTRALIAN PLANT SPECIES

The effects of light quality and quantity on growth and development of Anigozanthos bicolor and Zieria fraseria grown in vitro was investigated.
Three white light intensities of 40, 80 and 200 &#181mol m^-2s^-1; light of five spectral quantities: white (390-760 nm), blue (450-492 nm), green (492-550 nm), yellow (550-588 nm) and red (647-770 nm) all at intensity of 15 &#181mol m^-2s^-1; and five light-dark cycles: 4L2D, 6L6D, 12L12D, 16L8D and 24L all at intensity of 15 &#181mol m^-2s^-1 were applied to plantlets on three media, basal (MS medium no added hormones), multiplication medium (MS supplemented with cytokinins) and rooting medium (MS supplemented with auxins).
Total rhizome number and dry weight of A. bicolor plantlets after 6 weeks of growth was positively affected by high light intensities of 80 to 200 &#181mol m^-2s^-1 and short light-dark cycle of 4L2D. The light spectrum was not critical for rhizome production in A. bicolor.
Shoot dry weight of Z. fraseria was highest in plantlets grown under 200 &#181mol m^-2s^-1 irradiance, however the quality of plantlets was lowest.
Chlorophyll content decreased as the light intensity increased.
Shoot length was positively affected by blue light.
Light cycle had no effect on the productivity but shorter photoperiods reduced shoot length.

IV International Symposium on New Floricultural Crops

T. Tapingkae, A. Taji

Anigozanthos, Australian plants, light, micropropagation, plant growth regulators, Zieria

https://doi.org/10.17660/ActaHortic.2000.541.43