Studies On The Tissue Culture And Polyploidy Inducement Of Photinia Serrulata Lindl.

Photinia serrulata Lindl is an excellent kind of landscape tree. The major object of tissue culture study is to exploit the technique systems of rapid propagation and regeneration, in ordering to offer material and technique supports for resistance breeding of Photinia by transforming with Cold-resistant Gene. Using the fresh shoots, seed and leaves as the materials, the optimal medium and culture condition are studied, finding the methods to solve the matter of explants pollution and browning. And in this study, the methods to induce polyploidy Photinia by adding colchicines solution of different concentration combined different treatment period to the tip of the seedlings was systematically studied. The major results as following:1.The concentration of disinfectant mercuric chloride and alcohol for stems is respectively 0.1% and 75%, the optimizing time of disinfection is: alcohol 30 seconds followed by chloride 7 minutes. The optimizing medium for initial culture is: MS+BA2.0+NAA0.1,sugar (30mg/l) and agar(7.5mg/l). The optimizing multiplication medium is: MS+BA1.0 mg/l +NAA0.1 mg/l,the regenerating buds grow fast on this medium, and the leaves are green, the stems are strong, the secondary buds are more than others, and besides, there was no vertrification.When the BA in the medium is more than 2.0mg,vertrification is found in regenerations.2.The influencing factors on browning of explants of the juvenile shoots in tissue culture of Photinia serrulata Lindl. were studied in the experiments. The results show that adding antioxidant and absorbing substance, treating explants in low temperature, decreasing the macro-elements concentration and the material have effects on the rate of browning. And the most efficient methods of decreasing the rate of browning are using the medium containing PVP0.75 g·l-1 and keeping in 4℃for 5 days. The best material is the part of the juvenile shoot with the 2nd-3rd buds, and April is the best month for material collecting. Reducing the macro-elements concentration is also an effective...