Affects of some factors on in vitro flowering of torenia (Torenia fournieri L.)

Abstract

Transformation from vegetative to reproductive stage (flowering stage) depends on a lot of elements: physical and chemical elements, age of explant source, and plant growth regulators. In this study, we examined some elements that affect to differentiating ability of  in vitro  Torenia fournieriL. flower shoot. Results showed that the older theshoots were, the higher the percentage of flowering shoot formation would be. 60-day-old shoots gave the highest percentage of flowering shoot formation (65 %) after 30 day culture. Moreover, the amount of macronutrients and micronutrients, sucrose concentration, growth regulators, activated charcoal and lighting conditions affect significantly the flowering ability. Shoots cultured on plant growth regulator free ¼ MS media supplemented with 60 g.l^-1sucrose and 1 g.l^-1 activated charcoal under a 10 h light (45 µmol.m^-2.s^-1)/14h dark photoperiod resulted in the best flowering shoot formation of  T. fournieri  shoots culturedin vitro  (87.18 %, 2.80 flower buds/explant).  In vitro flowers and the ex vitroones have no significant difference in their morphology and color.