Effect of plant growth regulators on germination of immature orchid seeds in two ‎culture media laboratory ‎

With the aim of investigate the effect of different plant growth regulators on orchid immature seed germination, Dendrobium nobile Lindl spicies, was performed in two experimental MS and M culture media, as a composite analysis in a randomized complete design with 4 replications in Balouchestan Agricultural and Natural Resources Research and Education Center during 2015-2016 years. Twenty-two plant growth regulator treatments included control (no use of growth regulator), 4 concentrations of NAA or α-Naphthaleneacetic acid (0.5, 1, 1.5 and 2 mgl-1), 4 concentrations of Kin or Kinetin (0.5, 1, 1.5 and 2 mgl-1), 4 concentrations of IAA or Indole-3-acetic acid (0.5, 1, 1.5 and 2 mgl-1), 3 combinations of Kin+IAA{(0.5+1), (1+0.5) and (1+1)} mgl-1, 3 combinations of NAA+IAA{(0.5+1), (1+0.5) and (1+1)} mgl-1, and 3 combinations of NAA+Kin{(0.5+1), (1+0.5) and (1+1)} mgl-1 on two culture media. The simple effect of the culture medium on all measured traits was not significant, while the simple effect of growth regulators as well as the interaction effect of growth regulators and culture medium on all traits measured at the level of 1% was significant. The results showed that the lowest and highest percentage of germination were observed in control treatments and NAA+Kin (1+0.5mgl-1), in M culture medium, respectively. The shortest time to start germination observed under application of NAA;1.5mgl-1 inM culture medium, and the longest time to start germination was happened in the absence of hormone use in the both culture media. Also, the shortest time to spherule formation, was observed under application of NAA;1.5mgl-1 inM culture medium, and the longest time to spherule formation was occurred under conditions of non-hormone use in the both culture media and Kin+IAA(1+1mgl-1) treatment in MS culture medium. The shortest and longest duration to protocorm formation, was observed under application of NAA;1.5mgl-1 in M culture medium, and in conditions of non-use of hormones in the both culture media, respectively.In general, NAA;1.5mgl-1 treatment in M culture medium was the best and most economical treatment in compared to other treatments in the two culture media, which are the result of combinations and concentrations the elements in this culture medium for orchids.