Establishment of an Embryonic Tip Regeneration System of Soybean

ABSTRACT In order to establish an optimal soybean embryonic tip regeneration system that can serve as soybean genetic transformation receptor, and be used for the study of genetic function verification, the influences of single factor on the adventitious bud of embryonic tip induction, elongation and rooting stage, are researched and compared.The single factors includes seeds soaking time, different kinds of hormones, different concentration of hormone and different concentration of sucrose. By one-way ANOVA and LSD ad hoc test , the results show that, for the embryonic tip adventitious bud induction stage, 12h is the optimal seeds soaking time, 2.0mg·L-1 is the optimal concentration of 6-Benzyl Aminopurine(6-BA), for the embryonic tip adventitious bud elongation stage, 0.2mg·L-1 indole-3-butyric acid (IBA) is optimal and 2.0mg·L-1Gibberellic acid (GA3) is optimal, and for the adventitious bud of embryonic tip rooting stage, 2.0mg·L-1 IBA is optimal,the average rooting rate is 93.34%. An Optimal embryonic tip regeneration system is established, and optimum mediums in different stages are found.

Genetic variation and evolutionary demography of Fenneropenaeus chinensis populations, as revealed by the analysis of mitochondrial control region sequences

Genetic variation and evolutionary demography of the shrimp Fenneropenaeus chinensis were investigated using sequence data of the complete mitochondrial control region (CR). Fragments of 993 bp of the CR were sequenced for 93 individuals from five localities over most of the species' range in the Yellow Sea and the Bohai Sea. There were 84 variable sites defining 68 haplotypes. Haplotype diversity levels were very high (0.95 ± 0.03-0.99 ± 0.02) in F. chinensis populations, whereas those of nucleotide diversity were moderate to low (0.66 ± 0.36 percent-0.84 ± 0.46 percent). Analysis of molecular variance and conventional population statistics (F ST) revealed no significant genetic structure throughout the range of F. chinensis. Mismatch distribution, estimates of population parameters and neutrality tests revealed that the significant fluctuations and shallow coalescence of mtDNA genealogies observed were coincident with estimated demographic parameters and neutrality tests, in implying important past-population size fluctuations or range expansion. Isolation with Migration (IM) coalescence results suggest that F. chinensis, distributed along the coasts of northern China and the Korean Peninsula (about 1000 km apart), diverged recently, the estimated time-split being 12,800 (7,400-18,600) years ago.