Studies On Somaclonal Variation And Mutagenic Effects Of NaN₃ Of Roses (Floribunda Roses)

Floribunda roses, which are characterized with abundant colors, long inflorescence hardiness,luxuriant branches and leaves, cold-resistant, drought—resistant, strong adaptability and easy tomanage and so on, are good virescence materials and have great value in commerce. But they havefew cultivars and most of them are based on importion. Cultivars of Floribunda roses. with propertyright to china are lacking. Therefore selection breeding of new cultivars with great ornamentalvalue and cold-resistant cultivars are very importantSexual crossing breeding and bud mutation selection breeding are conventional breedingmethods in Floribunda roses. Beacause the complexity of genome and sexual incompatibilitiescrossing conventional breeding methods are difficult to conduct. Bud mutation selection breedingand chemical mutation breeding become important breeding methods.somaclonal variation arecommon during tissue culture. Chemical mutation breeding can produce more mutation. Studieson somaclonal variation and Chemical mutation ,and analysis on offsprings from Chemical mutationplants by DNA molecular markers technique are significant .Selection breeding by chemicalmutation to produce new cultivars have important value in theory and practical production.In this study 2003 05-7 varieties were selected from the 8 varieties of 200305-1to 200305-8.Floral organ of 2003 05-7 varieties as explants to callus induction and plants regeneration andchemicalmutation of in vitro shoots with NaN₃ were conducted respectively. Plants fromsomaclonal variation and chemical mutation mutation were analysed by ISSR molecular marks, toproduce available mutation. Conclusions as follows:1 Different parts of floral organ of Floribunda roses were used as explants to induce callus. Culturemedium optimum to receptacle was MS+6-BAlmg/L+2, 4-D0.5 mg/L+KT1.5mg/L; Culturemedium optimum to petals was MS+6-BAlmg/L+2,4-D0.5mg/L+NAAlmg/L; Culture mediumoptimum to bennet wasMS+2, 4-D0.5 mg/L+TDZ1.5mg/L; Culture medium optimum to ovarywas MS+6-BA1mg/L+KT1.5mg/L+TDZ1.5mg/L.2 Subculture medium optimum to callus of petals was MS+6-BA1 mg/L+KTlmg/L+2,4-D0.5mg/L; Organogenesis medium optimum to callus of petals was MS+6-BAlmg/L+NAA 0.5mg/L+GA₃0.3 mg/L.3 Half-death doseage of NaN₃ to Floribunda roses was 150mg/L. The effect of NaN₃ to buddifferentiation was stronger with higher concentration, which showed bud differentiation rate declined.4 ISSR molecular markes analysis were conducted in 50 samples from 10 offsprings ofsomaclonal variation and 150 samples from 30 offsprings of chemical mutation. Mutation rate of 10offsprings of somadonal variation was 8ï¼…, 4 differential bands were produced; Mutation rate of 30offsprings from chemical mutation with NaN3 was 17.3ï¼…, 26 differential bands were produced.Mutation rate of chemical mutation was higher than somaclonal variation. But chemical mutationwas disadvantageous to plant growth and differentiation. Somaclonal variation breeding and chemicalmutation breeding should be combined to produce more new good cultivars.