Horticultural Science and Technology ISSN:1226-8763(Print) 2465-8588(Online) 원예과학기술지

This study aimed to screen and clonally propagate high and low Ca- and Fe-producing Amaranthus dubius genotypes and to test the resulting clonal progeny ex vitro for their Fe and Ca content. Seven genotypes (G) with varying levels of Ca and Fe were selected from 50 A. dubius seedlings and then micropropagated using nodal explants. They were acclimatised and grown in the greenhouse for 90 days on either soil or soil and vermiculite (1:1). Ca and Fe levels of the clones were determined at days 15, 30, 60, 80, and 90 following 21 days of acclimatisation and compared to those of 60-day-old parent genotypes. In general, the Ca levels of the clones of the tested genotypes were similar to those of their parents at day 15 and then increased up to 90 days, regardless of the substrate. In contrast, on both substrates, at day 15, the Fe levels were the same or higher in the clones compared with their parents and then decreased with time. Amongst the clonal genotypes, the mean plasticity indices (MPIs) were low and ranged from 0.12 to 0.43, 0.13 to 0.42, and 0.11 to 0.21 for shoot growth, Ca content, and Fe content, respectively. The clones of G41 were found to be the most plastic (MPI = 0.28), while the clones of G15 were the least plastic (MPI = 0.15). Overall, there is an indication that the number of leaves, their biomass, and their Ca and Fe contents are not negatively affected by low nutrient soils, which may be useful to communities who cannot afford to apply fertilisers.