Proceedings Volume 2010 (format .pdf) - SimpBTH

Table 2. - Secondary somatic embryogenesis from spinach somatic embryos cultured onMS medium with 20 µM NAA and 5 µM GA 3 and variable levels of hygromycin (hyg).hyg(mg/l)Frequency ofsecondary somaticembryogenesis (%)Mean ± SENo. of secondarysomatic embryos perprymary embryoMean ± SESSENecroticexplants%0 87.5 ± 0.9 ab 4.36 ± 0.05 b 3.81 6.1 ± 1.6 c1 95.3 ± 1.8 a 6.29 ± 0.05 a 5.99 8.9 ± 2.4 c2.5 81.7 ± 0.2 ab 5.35 ± 0.06 a 4.37 6.1 ± 1.6 c5 75.9 ± 1.9 ab 2.73 ± 0.05 bc 2.07 30.2 ± 1.7 bc7.5 69.1 ± 2.6 b 2.11 ± 0.04 c 1.46 53.4 ± 3.3 b10 57.8 ± 1.1 bc 0.71 ± 0.03 d 0.41 98.1 ± 0.6 a12.5 31.2 ± 2.2 cd 0.21 ± 0.02 de 0.06 100 a15 25.0 ± 1.8 cd 0.11 ± 0.01 de 0.03 99.2 ± 0.8 a20 7.4 ± 1.3 d 0.01 ± 0 e 0 100 aData indicate the mean ± standard error. Two samples, each with 15 subsamples (n = 30), were usedper treatment. Treatments denoted by the same letter are not significantly different (P ≤ 0.05)according to Duncan's test. SSE - secondary somatic embryogenesis, SE - standard error.116Fig. 2. - Secondary somatic embryo regeneration from somatic embryos cultured on MSmedium supplemented with 20 µM NAA, 5 µM GA 3 and a) 0 mg/l hyg, b) 1 mg/l hygand c) 7.5 mg/l hyg. a-c bar = 1 cm.This study suggests 10 mg/l hyg as suitable level for selection of transgeniccells, at least under these experimental conditions. However, complete absence ofproliferation was attained at 20 mg/l hyg. Chin et al. (2009) used this concentrationto select transformed cells from calli induced from spinach leaf fragments.