Studies On Observation And Classification Of Pollens In Male Plants Of Ginkgo Biloba L.

Ginkgo biloba L. , which is dioecious, is the most ancient relict plant in seed plants.Gingko is not only the"live fossil"to study the evolution of plants , but also has high economic,social and ecological value.Pollen of gingko males has scientific and develpmental value.In this study, 89 male plants of Ginkgo bliloba L. collected from three product site of Yangzhou,Xuzhou of Jiangsu province and Yangzhou University germplasm garden were usesd as materials to collect the male inflorescences in the full flowering stage for measureing related indexes, and to observe with OM,SEM,TEM and analyze with energy spectrum. The results show that:1. The inflorescence of male plant is 1.562 cm~3.457 cm in length,0.385 cm~0.916 cm in breadth,2.71～6.42 in ratio of lenth to breadth, has 31～83 pairs of anther sac,and its stalk is 0.399 cm～1.124cm in length,their coefficients of variation(CV%)is 15.536%,18.422%,23.349%,19% and 21.63%, respectivly.There are notable differences among inflorescence length,inflorescence width,flower-shaped index and the number of anther / inflorescence of different male plants'short branch with flower.2. The fresh pollen is spherical or elliptical,its polar axis and equatorial axis is 19.93μm～25.63μm and 27.65μm～33.97μm in length respectivly,the ratio of polar axis to equatorial axis (P/E)is 0.64～0.86,their CV is 4.87%,6.37% and 6.72% respectivly; The dry pollen shows as the shape of a seed stone of gingko, its polar axis and equatorial axis is 12.05μm ~ 20.29μm and 26.03μm ~ 40.78μm in length respectivly,the index of pollen shape(P/E)is 0.43～0.56, their CV is 13.75%, 13.26% and 4.99% respectivly; the differences among polar axis,equatorial axis and P/E of dry polles in different male plants have reached significant difference.3. The fresh pollen in which the proximal germination locality shows as the shape of a furrow, is 22.67μm in polar axis, 30.73μm in equatorial axis, 0.74 in P/E. The length of polar axis is shorted by losing water. Polar axis,equatorial axis and P/E are 15.84μm,33.31μm and 0.48, respectively.4. After cluster analysis on the indexes of polar axis,equatorial axis and P/E with intercept line of L2=(3.28209+ 2.74821)/2=3.01515, the 89 experimental male plants in this study could be divided into four types, in which the first, second, third and foruth type included 4, 34, 47and 4 ones respectivly.The average quantity of anther sac/inflorescence is 54.0.The quantity ofⅠ,Ⅳtype is fewer than averge, wich are 47.0 and 43.0 respectively.The P/E of dry pollen is 0.51,0.47,0.47,0.47, respectivley.5.In these tested gingko males,Ⅰ-type are taken from Yangzhou,Ⅱ-type consist of 21 plants taken from Yangzhou,7 plants taken from Gingko Orchard of Yangzhou University and 6 plants taken from Xuzhou,Ⅲ-type consist of 31 plants taken from Yangzhou,14 plants taken from Gingko Orchard of Yangzhou University and 2 plants taken from Xuzhou,Ⅳ-type consist of 2 plants taken from Gingko Orchard of Yangzhou University and 2 plants taken from Xuzhou.The distribution of gingko males germplasm not only has obvious history heritage but also mutual exchange and mobility in a certain degree.6. There are significant difference between male gingko pollen surface ornamentation.The external veins of pollen could be classified into four types: A. mosaic spherical pearl-like; B. mosaic conch–like; C. mosaic lineolatus-like; D. mosaic curve-like.7. The pollen wall ,exine of wich is yellow,is 0.800μm～1.565μm in thinckness, its intine and exine is 0.098μm～0.549μm and 0.575μm～1.125μm in thinckness respectivly, their CV is 14.3%,38.2% and 15.5% respectivly.The variation of intine is more significant than exine's.There was a significant difference among the four styles, the StyleⅡis relatively large in thinckness.8. .The spectrum analysis of pollen show that: the essential plant nutrients contained in gingko pollen are mainly N, P, K, Ca, Mg,their content are(atomic percentage) 29.73%, 0.27%, 0.30%, 0.04%, 0.14% respectivly.The K inorganic nutrient content is the highest of all elements in the pollen content.The content of four nutrients have reached significant difference.(2) Through the spectrum analysis results of male gingko pollen subjectded to the four ages, P,K,Ca,Mg ,four inorganic nutrients are less influenced by age,their contents don't have significant changes with age growing.9. Insignificant differences of correlations exist among indices of the crown-shaped,flower-shaped and pollen, which indicate that the genetic stability of gingko pollen is determined by gene expression of itself, so the classification on pollen of gingko's male plant has rationality and feasibility.The above results provides a theoretical basis and technological support for the classification of germplasm resources, optimizing allocation, development and utilization of male plant in gingko.