In all media pHwas adjusted to 5.8 using 1 mol l−1 NaOHor 1 mol l−1 HCl. Each treatment was replicated 15 times in 200 ml sterile clear glass jars with 30 ml of media solution. Approximately 100 seeds, each sterilized for 5 min in 1% NaOCl, were placed in each jar under sterile conditions.Seed placement was done by suspending seeds in 0.1% autoclaved Agar solution using a sterile syringe and pipetting out 1 ml for each replicate.After seed placement, the exact number of seeds in each jar was counted.Seeds were then allowed to germinate in tissue culture rooms under a 12 h dark
and 12 h light cycle. We used cool white fluorescent lights with approximately 200 μ molm−2 s−1, for the photoperiod cycle condition. In orchids germination and seedling development are divided into six stages including stage 0 the ungerminated seed and were scored as described by Arditti (1967). Germination (stage 1), defined as imbibed seeds still covered by testa and with a white and green color visual to the eye, was assessed three months after seed sowing