| The experiment of interspecific hybridization had been conducted with 3 cultivars, a total of three combinations were tried, and the molecule identification of 14 offspring from the cross-combinations by AFLP showed that most offspring were real and mother-closed hybrids. In offsprings, most of the AFLP bands were inherited from had different from their parents but some bands were novel bands, which meaned that the offsprings not only inherited the characteristics of parents, but also had new variation.MSAP technique was used to detect the DNA methylation level of freesia parents and hybrids, in white Freesia hybridaⅡ×pink Freesia hybrida hybrid system, 16 primer pairs generated 711 sites, the DNA methylation level was between 14.09%-15.77%, in pink Freesia hybrida×yellow Freesia hybridaⅡhybrid system, 21 primer pairs generated 619 sites, and the DNA methylation level was between 11.38%-12.75%, CG methylation sites was the principal methylation pattern. Furthermore, the MSAP data were dissected into methylation-sensitive (MSP) and methylation -insensitive polymorphisms (MISP), cluster analysis and principal component analysis were also been done,and the results was similar to AFLP.Although in the majority of CCGG sites, DNA methylation showed Mendelian inheritance from parental lines to hybrids, alterations in methylation pattern were detected in some hybrids studied at certain frequencies, the variation ratio was 0.84% and 0.16% in white Freesia hybridaⅡ×pink Freesia hybrida hybrid system and in pink Freesia hybrida×yellow Freesia hybridaⅡrespectively. Compared with the mid-parent, DNA methylation level of most hybrid offspring was a little lower.We analyzed the various correlations of the AFLP and MSAP data including methylate sensitive polymorphism (MSP) and methylate insensitive polymorphism (MISP), the correlation of MSP and MISP was significant in both hybrid system, certain association between MSP and AFLP or MISP and AFLP was detected in white Freesia hybridaⅡ×pink Freesia hybrida hybrid system, but none of the correlations of them were detected in another hybrid system.For efficient regeneration of this flower from young inflorescence and rachillae in tetraploid, we developed a simple in vitro micropropagation protocol. Explants of Freesia hybrida can regenerate plantlets through somatic embryogenesis via two kinds of pathways, that is, directly from the epidermal cells or indirectly from an embryonic callus, depending on the exogenous plant growth regulators (PGRs) used in the culture media. In direct embryogenesis, when the explants were cultured on Murashige and Skoog (MS) medium supplemented with 2mg/L indole acetic acid (IAA) and 1mg/L 6-benzylaminopurine (6-BA), the induction rate was 84% for young inflorescence and 100% for rachillae. In indirect embryogenesis, embryonic calluses were formed when the culture medium contained 5 mg/L 6-BA and 1mg/L 2,4-dichlorophenoxy acetic acid (2,4-D), and the induction rate was 92.4% for young inflorescence and 100% for rachillae. After the embryonic calluses were transferred to the medium supplemented with 2mg/L IAA and 3mg/L 6-BA, they could develop into plantlets with roots.In assessing the two regeneration pathways in terms of genetic and epigenetic fidelity of the regenerants, two kinds of molecular markers [amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP)] were employed. The AFLP analysis used 20 primer pairs that yielded 916 scorable bands among the donor plant and 11 regenerants from direct embryogenesis, of which 8 (0.87%) were polymorphic. The regenerants from indirect embryogenesis had 1075 clear bands of which 3 (0.27%) were polymorphic scorable bands from 18 primer pairs. Moreover, the variant band patterns included two types, that is, loss-of-original and gain-of-novel bands. MSAP analysis revealed that tissue culturing of the flower induced DNA cytosine methylation alterations in both CG and CNG levels and patterns compared with the donor plant. The variation rate was 1.1 and 1.3% for the direct and indirect embryogenesis pathways, respectively. The findings show that tissue culture of flowering plants is a form of stress which can induce some heritable epigenetic variations and should be considered in future long-term genotype preservation programs of Freesia hybridaUsing the young inflorescence segments of Freesia refracta as explants, indirect somatic embryogenesis of somatic cells was induced in a N6 medium supplemented with some exogenous hormones. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) was used for the analysis of soluble proteins produced during the somatic embryogenesis of this plant. There are six polypeptides, which might play some roles in the process of somatic embryo development. Three polypeptides (45, 53 and 55 kD) were detected in the stages of embryogenic callus, globular embryoid, and embryoid with coleoptiles, except the embryoid with leaf. One polypeptide (83 kD) was specific for the stages of embryoid with coleoptiles and embryoid with leaf. One polypeptide (37 kD) was detected in the first two stages, namely, embryogenic callus and globular embryoid. One polypeptide (35 kD) was regularly synthesized in each stage, from embryogenic callus to embryoid with leaf.Floral fragrance compounds of one freesia specie, four cultivars and ten hybrids of two cultivars were studied using static headspace extraction for sample preparation followed by GC-MS analysis. In total, 43 compounds were identified and the number of compounds per species ranged between 3 and 25. Main compounds dominated by only 2–4 compounds in most species were isoprenoids and fatty acid derivatives accompanied by sulphur-containing compounds and nitrogen-containing compounds. Among the compounds, linalool (26.6-85.4%) was the major component and was detected from all the flowers. In the parents and the studied progeny, the laws of segregation of the scent traits in this cross were unveiled, stable inheritance of the main components was observed. Furthermore, In vitro analysis showed that the pistil and petal were the main producers of the floral fragrance compoundsBased on the measurement of S?rensen's index of similarity (Is) nonmetric multidimensional scaling (MDS) was used to detect meaningful underlying dimensions and to visualize similarities between the investigated species. The MDS analysis showed two groups of species. The results are discussed in relation to pollination, especially by butterflies, moths, and bees.
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