Application of growth models to evaluate the microenvironmental conditions using tissue culture plantlets of Phalaenopsis Sogo Yukidian ‘V3’

• Factors affecting the plantlet growth on all culture day were studied.
• The effect of temperature and light irradiance on growth characteristics was investigated.
• A four-parameter logistics model for growth rate was used.
• The environmental factors all had a significant effect on growth characteristics.
• The optimal conditions for plantlets culture of Phalaenopsis Sogo Yukidian ‘V3’ were proposed.

Phalaenopsis, an important pot plants worldwide, are propagated with a tissue culture technique. The aim of the present study was to validate growth models for Phalaenopsis plantlets with measured data. Effect of temperature and light irradiance on the growth characteristics was investigated by total weight, total leaf area and weight ratio of shoot to root weight for Phalaenopsis Sogo Yukidian ‘V3’. Relationship between culture days and total weight and leaf area of plantlets with was analyzed by nonlinear regression analysis. A four-parameter logistics model for growth rate was selected used as the growth index for further study. The relationships between environmental factors and the total weight, total leaf area of plantlets and the weight ratio of leaf to root were evaluated by multiple regression analysis. These environmental factors all had a significant effect on the growth characteristics. The optimal microclimate conditions for plantlets culture of Phalaenopsis Sogo Yukidian ‘V3’ determined from the regression results were light irradiance 40–60 μmol m−2 s−1, light temperature 29–32 °C and dark temperature 22–25 °C. The results can be useful information for propagating Phalaenopsis plantlets.