Optimization of Tissue Culture Propagation Technology for Cattleya Protocorms

This study analyzes the factors affecting the proliferation of Cattleya protocorms in vitro and develops an efficient rapid micropropagation system to achieve high-efficiency propagation of excellent Cattleya varieties. Using the bulbs of 10 different Cattleya hybrid combinations as materials, the study investigates the effects of hybrid combinations, medium additives, plant growth regulators, and types of media on the proliferation of Cattleya protocorms. The results showed that under the same culture conditions, among the ten different hybrid combinations, except for ZX-2 and ZX-3, there was no significant difference in the proliferation coefficient., there are significant differences among the remaining hybrid combinations. ZX-6 had the highest proliferation coefficient of 5.83.Further study using ZX-6 original bulbs as the material found, The optimal combination and concentration of additives were 3 g·L⁻¹ peptone and 0.5 g·L⁻¹ Hyponex No.1, under which the ZX-6 protocorm proliferation coefficient reached 4.34. The impact of plant growth regulators on Cattleya protocorms proliferation varied, ranked in order of influence as 6-BA ＞ NAA ＞ KT, with both 6-BA and NAA having extremely significant effects on protocorm proliferation（P＜0.01）. The most suitable hormone combination for ZX-6 protocorm proliferation was A₂B₂C₁, that is, 6-BA 0.5 mg·L⁻¹+NAA 0.2 mg·L⁻¹,+ KT 0.25 mg·L⁻¹. Different basal media significantly affected protocorm proliferation. Appropriately reducing the concentration of inorganic salts in the medium while adding a certain concentration of sucrose and activated carbon promoted the proliferation of Cattleya protocorms. The best proliferation effect for ZX-6 protocorms was achieved when the basal medium, sucrose concentration, and activated carbon concentration were 1/2 MS, 25 g·L⁻¹, and 0.5 g·L⁻¹ respectively. The experiment showed that the most suitable proliferation medium for ZX-6 Hybrid Combination was 1/2 MS supplemented with 6-BA 0.5 mg·L⁻¹, NAA 0.2 mg·L⁻¹, KT 0.25 mg·L⁻¹, peptone 3 g·L⁻¹, Hyponex No.1 0.5 g·L⁻¹, sucrose 25 g·L⁻¹, and activated carbon 0.5 g·L⁻¹.