Study On The Technique Of In Vitro Rapid Propagation Of Cattleya Hybrid

Cattleya is a general name of Cattleya genus. Its flowers is biger and brilliant, so it is called "Orchids King". It has been an important indoor foliage plants. Cattleya growths slowly, the rate of division propagation is low. And its seeds are difficult to germinate. So plant tissue culture technique is the best choice for propagation. At present, there are few studies on Cattleya hybrid, and reports on Cattleya hybrid tissue culture is even fewer. This study took Cattleya hybrid plantlet as material, did research on the shoot multiplication, rooting, and plantlet rapid grew. Provided a theoretical basis for Cattleya hybrid tissue culture and commercial production. The results were as follows:1. Taking plantlets of Cattleya hybrid as the testing material, different cytokinins, basic mediums, organic additives, activated charcoal, concentrations of GA3, genotypes, culture methods and time were studied on the shoot multiplication and growth. The results showed that the best culture medium was MS+6-BA2.0mg/L+coconut milk100ml/L+acti-vated charcoal1.Og/L+sucrose30g/L+agar5.5g/L, pH5.5. The multiplication coefficient was2.63and length of lateral buds was1.92cm after cultured6weeks by using this medium. Solid culture was better than liquid culture. And the better subculture cycle of Cattleya hybrid was6weeks. The genotypes had an important influence on shoot multiplication and growth. Two cultivars C1and C2were cultured in the same culture medium, the number of lateral buds C1less than C2, but the length of lateral buds C1longer significantly than C2.2. Taking plantlets of Cattleya hybrid without roots as the testing material, different auxins, basic mediums, concentrations of carbohydrate, organic additives, activated charcoal, genotypes and culture methods were studied on rooting and growth. The results showed that the best rooting medium was MS+NAA0.2mg/L+coconut milk100ml/L+sucrose30g/L+agar5.5g/L+activated charcoal1.0g/L, pH5.5. The rate of rooting was100%, average number of root was3.50and average length of root was2.13cm after cultured30days by using this medium. The genotypes had an important effect on rooting and growth. Two cultivars C1and C2were cultured in the same rooting medium, the mean number of roots C1less than C2, but the mean length of roots longer than C2. The best rooting method was two-step rooting method, plantlets cultured in medium added NAA1.0mg/L10d then transferred into medium without plant growth regulator. At that time the content of chlorophyll, soluble sugar and soluble protein was highest. And the root activity was the highest.3. Taking plantlets of Cattleya hybrid as the testing material, different concenteations of GA3, culture vessels, basic mediums, carbohydrates, organic additives and plantlet size were studied on growth rate and plantlets quality. The results showed that the best growth medium was MN800+6-BA0.5mg/L+GA30.1mg/L+sucrosel5g/L+glucosel5g/L+Banana juice200g/L+agar5.5g/L, pH5.5. The increment of plant height was1.93cm, dry matter percentage was9.35%and root-shoot ratio was0.750after30days by this medium. The larger volume of culture vessels promoted plantlets growth significantly. The larger plantlet was the best choice for fast grow, otherwise the plantlet overgrowth, and plantlet grew poorly.