A Study On Biological Characteristics Of Flowering And Karyotype Analysis Of Clematis L.Cultivars

For the beautiful showy and colorful blossoms,Clematis is a class of vine with high value of ornamental.Clematis resources are very rich in China,but the study on breeding research level of Clematis is far lower than abroad.The study on introduction and acclimatization of Clematis is very common in our country,but the research of hybridization is rarely encountered.In fact,this is beneficial to increase the varieties of Clematis.In order to provide a scientific basis for hybridization of Clematis,the phonological period and other ornamental characteristics,the pollen germination ratio and pollen tube growth,the pistil receptivity,the karyotype analysis of different varieties of Clematis were studied.The conclusions were as follows:1.In order to summariza the flowering period and ornamental characteristics,the phonological period,colors,average flower diameters of 22 varieties of Clematis were studied,and the blossom time and ornamental characteristics were discussed.The varieties of early large-flowered group bloomed earlier and faster than the late large-flowered group,but the latter was longer than the former on blossom time.The flowering period of early large-flowered group is April 4th to April 26 th,the late large-flowered group is April 15 th to May 9th.The germination period and leaf-expansion period is overlapped.There are 16 colors in all the varieties of Clematis,and most of them are gradient colors.The flower diameters varies within relatively wide and most of them are medium-sized.2.Determination of pollen germination ratio,measurement of pollen tube growth and pistil receptivity experiment were done on all varieties of Clematis.There was a significant difference in the effect of the interaction between different cultivars,sucrose,boric acid on the pollen germination ratio and a significant difference in pollen germination ratio and pollen tube length of9 varieties in different medium also.The pollen germination ratio of 9 varieties is 2.35~63.44%,the pollen tube length is 27.0~136.5?m.The pistil of 9 varieties were receptivity in large flower bud and relaxed flower bud.3.The chromosome types and karyotypes of 13 Clematis cultivars' natural growth of tender root tip materials were studies by the method of cell wall degradation and hypotonic treatment for chromosome preparations and Giemsa C-banding.The results indicated that all the chromosomesof the 13 provenances were diploids.There were 2 types of chromosome karyotypes classified from the morphological observation: 2n=2x=16=10m+4st+2t and 2n=2x=16=10m+6st,and the satellites were found in every cultivars' chromosomes of number 6,number 7 and number 8.The karyotypes are “2A” for both,it means they have a great deal of similarity.The differences between the 13 varieties of karyotype parameters can be used as the basis for classification of Clematis and the determination of genetic relationship.The research provide a preliminary cytological data on the protection,the study on evolutionary trend,and hybridization of Clematis.