Studies On Systematics Evolvement And Environmental Adaptation Of Leaf Epidermis And Abortion Mechanism Of Cross Embryo In Syringa

Leaf epidermis traits of seven wild germplasms subjected to five series of Syringa were observed, meanwhile, the differences in their adaptative responses were compared and the linking on systematics was discussed at the epidermis structure level. The results showed that S. amurensis and S. oblata presented more structural adaptation traits compared with the other five species and it is helpful to understand the fact of two wild-spread and narrowly regional distributions for the other species respectively. The comparison on responsive difference special for S. pinnatifolia between heterogeneous light habitats showed that the individuals grown in full sun have larger stomata density, smaller stomata opening and smaller epidermal cell size than those in the shade. The stomata long axes was relatively unchangeable wherever they were planted and stomata opening extent only attributed to the variety in latitudinal width of guard cell. Some systematic evidences were also supplemented depending on the integrative analysis of stomata apparatus, wax ornamentation, morphology of epidermal cell and anticlinal wall. It implied that S. amurensis and S. oblata are evolved species and Ser. Pinnatifoliae, Ser. Pubescentes and Ser. Villments have more closely systematic relationship. The leaf morphological comparisons in the long-term of adaptation based on the systematic evolution research will provide integrity morphological information and provide the basis for our further research on domestication adaptation.The abortion mechanism of combinations between S.velutina and S.microphylla in Syringa was explored from embyro morphological development and endogenous hormones compared with the fertility combination. The results showed that the abortion occurred in endosperm formation period,the development of embryo in abortion combination lagged behind the fertility combination. The analysis on embryo endogenous hormones showed that the endosperm abortion may correlated to lower level on Zr,iPA content and relatively higher ABA content in proembryo-formation.Simultaneously, normal development of embryo may need harmonic interaction and dynamic balance between the different endogenous hormones. The results for the future of breeding offer oversee a few theoretical bases.