This study was performed to determine the effect of Fe-EDTA in vitro on growth response and mineral nutrient uptake in orchids. Several terrestrial orchid species were used as materials : Cymbidium gyokuchin, Cymbidium ´Water King´, Calanthe discolor and Bletilla striata. Results obtained were as follow
Addition of Fe-EDTA had no effect on the growth of shoots and roots, fresh weight increase and mineral nutrient content in Cymbidium gyokuchin Makino var. soshin ´Kwanum´. In Cymbidium ´Water King´, the addition of 14-40 μM Fe-EDTA increased fresh weight and length of shoots and mineral nutrient uptake, but decreased number and fresh weight of roots.
In Calanthe discolor, shoot formation and growth were generally good in control except 40 μM Fe treatment showing longer shoot length. Root formation was also increased in control, but root growth was better by 3 μM Fe-EDTA treatment.
In Bletilla striata, the addition of 40 μM Fe-EDTA was effective on the formation and growth of shoots and roots, and inhibited leaf browning symptom.
There was no relationship between growth and mineral nutrient content of the plant tissue.
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