| Clematis patens belongs to Clematis L.in Ranunculaceae.It has rich design and color,beautiful flower shape and good character.It is a precious wild resource in the application of landscape in Northeast China.In order to broaden the propagation system of Clematis patens and increase the popularizing and landscape application of Clematis L.the biological characteristics of Clematis patens seeds were studied in this paper,and the methods of breaking dormancy of seeds were discussed.The propagation techniques suitable for Clematis L.cuttings were selected from the aspects of substrate,exogenous hormone and cuttings size,etc.The rooting mechanism of Clematis L.cuttings was revealed through the dynamic changes of nutrients and oxidase activity in cuttings.Specific research results are as follows:1.The fruit of Clematis grandis is achene-shaped with persistent style,and the seed shape is wide ovate or oval-shaped rhombus,about 7.13mm in length and 4.57mm in width,and the weight of 1,000 seeds is about 20.67g.The seed coat was permeable.The seed water absorption rate reached 97%after 28 hours of water absorption,and there was no water absorption barrier.The viability of Clematis patens seeds is about 82%.2.In the germinated experimental groups,Clematis patens was found to be light-needing seeds,and the germination rate was the highest,reaching 9.3%,under the variable temperature of 25℃ in the day and 15℃ in the night.In the study of dormancy inhibitors,the results showed that there were both inhibitors in the seed embryo and seed coat of R.simonii,and the seed embryo had a stronger inhibitory effect on the germination of Chinese cabbage seeds.In this study,four methods of gibberellin,low temperature stratification,variable temperature stratification and field sand storage combined with hormone treatment were used to induce the accelerated germination of Clematis macroflora seeds.It was found that 800mg/L GA3 solution stored in sand for 6 months had the best effect,and the germination rate could reach 79%3.Cutting substrate had significant effect on rooting rate and rooting characters of Clematis patens.The rooting rate of Clematis patens was the highest in the mixture of perlite+vermiculite+sand(1:1:1),which could reach 73.93%.Different kinds and concentrations of hormone screening tests showed that IBA group as a whole was much better than NAA group and ABT root powder rooting effect.The best effect was that the cuttings were soaked in IBA200 mg·L-1 for 1h,and the rooting rate was 75%.Based on the rooting indexes such as cuttings survival rate,rooting rate,root length and root effect index,Clematis macroflora should choose the top cuttings of the mother plant of 6～8cm and leave 2 leaflets to be cut in May in spring for the best rooting effect in the choice of cutting season,material location,cuttings length and leaves.4.The rooting type of Clematis patens was determined to be mixed rooting type,which could be emitted from the skin or callus during the rooting process.The rooting process of Clematis grandis can be divided into three stages:(1)lenticel initiation and callus induction(0-21d);(2)the expression stage of adventitious roots(21～28 days);③Elongation and development of adventitious roots(28～42d)5.During the cutting process of Clematis patens,the soluble sugar showed a double-peak trend of "down-up-down-up-up",starch showed a "down-up-up" trend,and protein showed a"up-down-down-up-up" trend.Although the change curves and trends of the three nutrients were slightly different,they were all consumed during the critical period of cuttings rooting.6.The activities of polyphenol oxidase(PPO),peroxidase(POD)and superoxide dismutase(SOD)showed a trend of "up-down",while the activities of IAAO showed a trend of"up-down-up".There was a direct relationship between the activities of four enzymes and the content of IAA in the plant. |
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