Studies on Transgen ic Acceptor System of Ground-CoverChrysanthemum Via Indirect Soma tic Embryogenesis

In this paper transgenic acceptor systems of chrysanthemum cv.‘Yurenmian’via indirect somatic embryogenesiswere established by three steps cultivation. The authors studied the effects of hormones, illumination intensity on indirect somatic embryogenesis through stem segments ( internodal segments) as explants. Results showed that: embryogeniccalli induction medium wasMS +KT 2. 0 mg· L-1 + 2, 4-D 2. 0 mg·L-1 +NAA 0. 5 mg·L-1 , 15 days later, yellowgreenish, compact nodular calliwere transferred embryogenic calli differentiationmediumMS plus KT 2. 0mg·L-1 , 2, 42D 1. 0 mg·L-1 and NAA 0. 5mg·L-1 for 15 days, andwere transferred differentiationmediumMS plus KT 2. 0mg·L-1and NAA 0. 5 mg·L-1 for 20 days. Illumination intensity was 1 000～2 000 lx. The highest rate of embryogenic callireached 95. 3%, the highest rate of embryogenic calli differentiation reached 92. 7%, average number of shoots per stemsegment explantwas 17. 8, and stability of regeneration shoots reached 99. 5%. Experiments of the sensitivity of antibiotics for transgenic accep tor systems of chrysanthemum cv.‘Yurenmian’via indirect somatic embryogenesis showed: the selection concentrations of kanamycin was 10 mg·L-1 , the selection concentrations of cefotaxime was 300 mg·L-1while embryogenic calliwere induced and 100 mg·L-1 while embryogenic calli differentiation.