A Preliminaryresearch On The Progration Of Fraxinus Hupehensis Chu,Shang Et Su.

Fraxinus hupehensis Chu,Shang et Su.is one of deciduous tree of Fraxinus.It is a unique species of Hubei province and one of the second batch of rare and endangered plants in China.Fraxinus hupehensishas high applictiong yalue.Since it was discoveredand used for 40 years,the resources of Fraxinus hupehensiswas badly damaged to the verge of exhaustion.However,the research related to Fraxinus hupehensiswas wery weak and lagging behind,and can not meet the needs of guiding production.In this study,by the systematic and fundamental research on the causes of seed dormancy,methods of breaking seed dormancy,cutting and tissue culture of Fraxinus hupehensis,the aim is to clarify the basic facts and rules of propagation of Fraxinus hupehensisand lay the foundation for the further research on the propagation of Fraxinus hupehensis,and at same time,it will provide practical guidance for the propagation of Fraxinus hupehensis.The results were summarized below:1.The abortive phenomenon of Fraxinus hupehensis seedswas very serious because of its low-quality seeds.The seeds having vitality only accounted for 31.3% ~32.7% of all the seeds.2.There was no difficulty in absorption of Fraxinus hupehensisseeds,so seed structure and permeability of water were not the cause of its dormancy.3.The excised embryos of Fraxinus hupehensis seeds could germinate and grow into seedling in the same year.4.Treatments of sown after harvest immediately,treatment of 98% sulfuric acid for 75 minutes and stratification outdoor for 90 days could break the dormancy of Fraxinus hupehensis seeds,and the treatments of sown after harvest immediately was best,but the effects of break the dormancy were not very good.The method of plant growth regulator with GA3 and 6-BA,physical method soaking at room temperature for 21 days had not broken the dormancy of Fraxinus hupehensis seeds.5.Inhibitors inhibiting the seed germination and seedling growth were obtained from the water and organic solvent extracts of fruiting wing,testa and endosperm of Fraxinus hupehensis seeds.The result of water extraction suggested that the first day was more effective than the fourth day,and the testa was the most effective part than those of the other two.Although organic solvent extraction was more effective than water extraction,the organic solvent extracts were differences among three parts of Fraxinus hupehensis seeds.6.Fraxinus hupehensis is a kind of tree with easy rooting and survival,and without any treatment,cuttings could take root,but the rooting rate was not too high.The treatment of Auxin growth regulators could promote rooting of cuttings of Fraxinus hupehensis,The concrete manifestation was that the treatment of ABT2(200mg/L)increased the rooting rate of Fraxinus hupehensis cuttings,and the treatment of IAA(100mg/L)could promote the root elongation of Fraxinus hupehensis cuttings.The treatments of proper concentration of NAA,IBA and IAA could promote the thickening of cuttings of Fraxinus hupehensis,and all the treatments of proper concentration of NAA,IAA,IBA,ABT1,and ABT2 could all significantly increase the number of secondary root of Fraxinus hupehensis cuttings.7.The results showed that the combined effect of 0.2% mercuric chloride solution for 5 minnutes was the best.On the WPM basal medium,the callus differentiation was induced by the explants of Fraxinus hupehensis shoots,and the recovery rate was 30%.The explants ofFraxinus hupehensis shoots were easy to be browned.Adding appropriate amount of PVP,and light culture after dark culture for 7 days cyold reduce the browning.