Study On Hybrid Progeny Of Annual Seedling Golden-leaf Ginkgo Biloba

Ginkgo(Ginkgo biloba L.),the "living fossil" in plant kingdom,is a rare species,which can be traced back to the Middle Age,is now widely used in street greening.At present,the ginkgo trees cultivated in China are mostly green-leaf,cultivating new ginkgo species with colorful leaves,strong resistance,high ornamental value is of great significance.In this paper,the pollination of Ginkgo biloba was studied.The results of hybrid pollination of Ginkgo biloba and the traits of pollinated seeds were investigated,and the growth and physiology of the annual seedling were studied in order to promote the cultivation and application of Ginkgo biloba.The results were listed as follows:(1)The results of pollination of Ginkgo biloba L.showed that the pollination success rate of Ginkgo biloba was higher than 90%.(2)Investigation of the seed obtained by the hybridization show that: two gold ginkgo hybrid seed nuclear looks like “Meihe” ginkgo seeds,which is smaller than any other kind of seeds.Seed moisture content is of 40% or more.There was an after-ripening phenomenon observed.In mid-September,golden-leaf ginkgo embryo is spherical.From mid-September to mid-November is the fast-growing period,after mid-November the growth speed was slowed down,and was completely matured in mid-December.Golden ginkgo seed germination rate of is over 80%,which indicates that it can be applied to seedling planting.(3)Through the observation of the growth process of annual seedling,the results showed that:It takes a long time — 35 days for ginkgo seeds to germinate without accelerating germination.The seedlings were divided into two types — yellow and green leaves.The proportion of yellow-leaf type of 1# was 56.9%,which was 53.63% of 2 #.The growth rhythm of seedlings is “fast followed by slow”.There was significant difference(P <0.05)between the hybrid and control group.The difference of the stem and the aboveground biomass,the total biomass and the moisture content of roots and leaves between the hybrid and control group was significant(P <0.05),and the difference of moisture content of stem between the hybrid and control group was not significant.(4)The results of physiological and biochemical studies showed that the content of starch in leaves was decreased and the content of soluble sugar was increased in Ginkgo biloba leaves.After the leaves were fully developed,the starch content in leaves was kept within a certain level,the content of soluble sugar was keep increasing.Protein content was increased in the early development of leaf development,and then retained a certain level,and brgan to rise sharply after the leaf aging.The leaf color was significantly related to the pigment content,chla/chal(car)and chlb/chl(car).The results showed that the chlorophyll content determined the value of a*,but not the main reason affecting the L* and b* values.The diurnal variation of photosynthesis showed the "double peak curve" in the sunny weather conditions.(5)The content of flavonoids in the green-leaves hybrids was 12.2mg/g,when it was 14.4mg/g in yellow-leaves type.The content of flavonoids reached highest in control group;then were the yellow-leaves hybrid,and green-leaves type at last.