Studies On The Reproductive Biology Of Paeonia Ostii'Feng Dan'

P. ostii'Feng Dan'was the research material. Measured the pollen germination rate before and after different conditions storage; Studied on the characteristics of sexual reproduction by different combinations of pollination; The double fertilization and the embryo and endosperm development were studied. The main results were as follows:1.The best culture medium formula:10% sucrose+0.05g/L boric acid; The suitable culture time was 5-6 hours for fresh pollen, and 7-8 hours for storage pollen; Low or ultra-low temperature was suitable for the storage of penoy pollen; The resistance of pollen varies for storage was according to species,'Feng Dan'was better than P. suffruticosa'Shima-nishiki'and P. suffruticosa'Mo Chi Jin Hui'. The germination rate of'Feng Dan'reached 69.23% after one year storage while 'Shima-nishiki'and'Mo Chi Jin Hui'were only 20%-30%.2.'Feng Dan'is cross-pollinated plant. Deals with natural crossing and artificial geitonogamy, the seed set is more than 50%; Geitonogamy and self-pollination have lower seed rate; Dealing without pollination has weak seed rate; There is high affinity in the cross between Paeonia ostii 'Feng Dan'and Japanese tree peony; There is poor affinity in the cross between Paeonia ostii'Feng Dan'and South Peony varieties, Paeonia ostii'Feng Dan'and American Peony varieties.3.After landing on a stigma pollen grain germinates at once;The fertilization method is micropyle fertilization, double fertilization process occurs in 4-48h after pollination, mainly in 10h after pollination. Sperm-egg fusion and sperm-polar nuclei fusion are almost simultaneously, the fusion of female and male nucleoli mark the end of double fertilization; belong to Pre-mitotic type of gamete fusion. The zygote dormancy period is approximately 8-12 hours.4. The endosperm of'Feng Dan'is nuclear type, the primary endosperm nucleus was division whiout dormancy, formed free-nuclear endosperm and its will continued for 23 days. The endosperm cellularization is finished 45 days after pollination and its growth-mature stage completed 85 days after pollination. Endosperm possessed a lipid nature at last. Embryo development is later than the endosperm, but the free-nuclear stage and cellularization stage are synchronous. Embryo development can be divided into three successive stages:proembryo stage, organ differentiation stage and growth-mature stage. The proembryo stage is most comllicated and it will last for 55 days, zygote division is not accompanied by the production of cell wall, formed free nuclei proembryo and began cellularization. And then develop into globular embryo, heart-shaped embryo, Torpedo-shaped embryo and cotyledonary embryo. The growth-mature stage will completed 125 days after pollination.This thesis deals with the sexual reproduction processes of'Feng Dan'preliminary, it has an important theoretical significance to peony breeding in the south of Yangtze River, and provide strong evidence for the phylogenetic of Paeoniaceae.