Studies On The Reproductive Biology Of Clematis Terniflora

The population of Clematis terniflora in the Laoshan forest farm, Nanjing, Jiangsu, wasselected to investigate the reproductive biology of C. terniflora, focusing on breeding system,flowering and pollination, seed germination, and cutting rooting. The main results were asfollows:1. Flowering phenology and breeding system of C. ternifloraThe flowers gathered in conical cyme. The florescence of the population lasted about25days from late May to late June while the full bloom period began in8th June. Based on the dataof pollen-ovule ratio, pollination experiment and out-crossing index, the breeding system of C.terniflora can be determined as a mixed-mating system dominated by outcrossing mechanisms,and partly self-compatible. As an indicator for ascertaining the breeding system of C. terniflora,P/O ratio is not suitable, while the value of OCI is helpful.2. Floral dynamic and pollination medium of C. ternifloraThe floret floral dynamic of C. terniflora can be divided into five periods: bud stage, femalestage, bisexual stage, male stage, and fade stage. C. terniflora is a species of asynchronousprotogynous on the individual level. This feature plays a role of reducing interference betweenmale and female functions. During the whole pollination phase the pollen maintained at a highvigor level, up to93.25%at full-blooming stage. The receptive stigma of C. terniflora can lastabout6days. The effective pollination way of C. terniflora was anemophilous pollination.Further studies are needed to explain the function of insects on the process of pollination.3. Biological characteristics of C. terniflora seedsThe fruit of C. terniflora is achene with ovate seeds, the horizontal and longitudinaldiameters are0.26±0.16cm and0.41±0.19cm respectively. The Weight per1000seeds is9.89±0.44g and the seed vigor by TTC method is67.8%. The germination rates of seeds arerelatively low. Results show that the optimum conditions on the germinate is the combination ofwet sand stratification,20mg/L6-BA and normal temperature, the germination percentage is53.33%.The temperature of stratification has the significant effects on the percentage ofgermination, and stratification with wet sand can bring forward the time of germinatesignificantly. Due to the higher linear correlation between electric conductivity and thegermination percentage of seeds, conductivity method can determine the vigour of C. ternifloraseeds rapidly. The contents of total soluble sugar, starch, soluble proteins, and crude fats degrade gradually during the stratification of seeds. Such physiological changes assure nutrient offersupply during seed germination.4. Cutting propagation technique of C. ternifloraRooting experiments were done on C. terniflora using half-lignified stem as cutting slips.Survey of rooting effects under different treatments indicate that6-BA is better than NAA as acutting-rooting promoter,50mg/L6-BA was the most suitable concentration for the rooting of C.terniflora cuttings, rooting percentage was up to71.11%, indicating that in the process of rootinglower concentration of hormone is effective.