Study On Photosynthetic Adaptability And Reproductive Technology Of Two Clematis Species

For the unique and colorful blossoms,Clematis has a “Vines Queen” reputation.It's a garden green plant material with highly ornamental value.However,the heat resistance of this genus is poor generally.So it has also become the main problem in garden application in south of the Yangtze River.Clematis finetiana and Clematis ganpiniana are native to Zhejiang province,have long florescence,profuse flower and strong climbing.And there are natural variation of flower and leaf color.They are excellent materials for breeding varieties and have a high value of garden application.Three-years-old seedlings of two clematis were used to observed and evaluated the photosynthetic adaptability in spring and summer,and provide a reference and promotion for garden application.Meanwhile,through cutting and tissue culture methods to preserve and expand the plants with fine variation.For breeding new species of Clematis accumulate germplasm resource.The results of the study were as follows:1.In the May and August,Lsp of C.finetiana was between 1100-1200 ?mol·m^-2·s^-1,Lcp was between 18-20 ?mol·m^-2·s^-1.Lsp of C.ganpiniana was similar to C.finetiana.Lcp had a significant difference between spring and summer.The Lcp was 24.78 ?mol·m^-2·s^-1 in spring,in summer was 61.35 ?mol·m^-2·s^-1.Diurnal variation in the net photosynthetic rate?Pn?for two species displayed single-peak curves without mid-depression in May and August.Compared to Pn,the transpiration rate?Tr?and stomatal conductance?Cond?showed similar changes,however,changes in intercellular CO2 concentration?Ci?were reversed,it showed a “V” curve changes.The decline of Pn was mainly affected by non-stoma factors.The chlorophyll fluorescence parameters including Fv/Fm?Fv?/Fm???PS??qP and NPQ of two plants in August were significantly lower than that in May except for F0,and the differences were obvious.In addition,the chlorophyll fluorescence parameters of C.ganpiniana declined more than C.finetiana.According to comprehensive analysis,C.finetiana and C.ganpiniana had great adaptability to light.The high temperature of August had no significant effect on C.finetiana,and had an appreciable influence on C.ganpiniana.The adaptability to high temperatyres of C.finetiana was superior to C.ganpiniana.2.The exogenous hormones,hormone concentration,soaking time and cuttage matrix had siginificant effect on rooting characters of cutting materials of C.finetiana.The primary and secondary effect between four factors is exogenous hormones > hormone concentration > cuttage matrix > soaking time.The best combination is: choose cuttings and dip them in 100 mg/L NAA for an hour,then cutting in the river sand.The shoot cutting of C.finetiana take root mainly with phloem and this belongs to Skin department took root.3.In the rooting process of C.finetiana,the content of soluble sugar and soluble protein changed with the rooting process,but were all decreased in rooting formation stage.The starch content kept declining during the whole process,the degradation rate of the cuttings processed by hormone is far more quickly than the comparison.Study on the the activity of the activity of related oxidative enzymes?POD,IAAO,PPO?showed that both of them were all increasing markedly in the rooting induction period,and then decreasing in the rooting expression period.The oxidase activity of cuttings processed by hormone is higher than the control.Contents of the endogenous hormones were closely related to rooting during Clematis finetiana cutting.The content of endogenous hormones except for ZR of treatment and control groups had the same trend.The IAA content and IAA/ABA ratio presented a identical trend that firsty increased in induction period,then lowered in expression period and again climed up in elongation period.The ABA and GA3 content showed a opposite trend with IAA that firsty declined in induction period,then went up in expression period and again went down in elongation period.ZR content keeped in a lower level in expression period.A higher level of IAA content and a low concentration of ABA,GA3 were required in induction period and elongation period of adventitious root formation.IBA could increse the IAA content in the cuttings,reduced the ABA?GA3?ZR content and play a role in promoting rooting of Clematis finetiana's cutting.4.The best sterilization time by HgCl₂?0.1%?was 5 minutes to the stems with buds,stems and petioles.The best sterilization time by HgCl₂?0.1%?was 3 minutes to leaves.The best initial medium of C.ganpiniana was MS+6-BA 1.0 mg?L-1+NAA 0.1 mg?L-1.The germination rate was 56.70%.In the process of callus induction,the stems and petioles was used as explants.The callus rate was low,callus morphology was poor and note suitable for proliferation culture.The best culture medium of callus induction from stems and petioles on C.ganpiniana was MS+6-BA 1.0 mg?L-1+NAA 0.5 mg?L-1+2,4-D 0.01 mg?L-1,induction rate was 16.70% and 10.00% respectively.