The Preliminary Study On Characteristics Of Reproductive Biology In Magnolia Sieboldii In Shenyang

Magnolia sieboldii K.Koch.is a national third-class endangered plant,and its resources are becoming increasingly endangered due to man-made damage to its habitats and its own reproductive defects.In this paper,the biological characteristics,pollen morphology and breeding system of Magnolia sieboldii K.Koch.and several magnolia plants cultivated in Shenyang were studied by biological observation,scanning electron microscopy and dissecting microscopy.The aim of this study is to provide a preliminary scientific basis for the reasons for the endangeredness of Magnolia sieboldii K.Koch.and its wide application.The results are as follows:1.The process of flowering can last for about 56 days,divided into four stages:bud stage,early flowering stage,flowering period and flowering stage.Sunny day,the single flower to complete the complete opening process that three round tenement all need to start 6-7h.Magnolia sieboldii K.Koch.has two times the flowering and secondary opening and closing phenomenon.The second flowering occurs at the end of July,but the flowering is small and the flowering period is shorter,about 14 days.2.There were no significant differences in the structure of the flower organs between Magnolia sieboldii K.Koch.,M.denudata,M.liliflora,M.soulangeana and Yulania×soulangeana D.L.Fu var.Hongmai.They are in the petal color,male and female morphology and the number of small differences.The color of the petals of Magnolia sieboldii is as light as white,while the stamens are darkest in color.The polar axis is about 20?m,the polar axis is about 45?m,has a single groove,the outer wall has two worm-like decoration,the surface hole is small and sparse,Compared with other species of Magnoliaceae,there are differences in size and outer wall decoration.3.The germination rate of fresh pollen was the highest at the flowering stage,and the germination rate was 89.5%on the medium of 10%sucrose + 0.05%boric acid.4.The age of Magnolia sieboldii K.Koch.is the strongest,with the flowering process gradually weakened,can grant time to last about 6h.There are male and female heterochromatic phenomenon and secondary opening and closing phenomenon,the pistil first stamens 28-36h mature,the days of Magnolia sieboldii K.Koch.of the secondary opening and closing phenomenon with the male and female heterochromatic phenomenon.5.According to the criteria of Dafni,the hybridization index of Magnolia sieboldii K.Koch.was 4,and the standard pollen ovule ratio of Cruden was 24144.74?39891.30.By comparing the two indexes,it was concluded that the breeding system was Sexual intercourse.The pollination test also proved that the self-incompatibility of Magnolia sieboldii K.Koch.and the seed setting rate of the heterotopic flower were significantly improved.