Study On Tissue Culture And Drought Resistance Of Ficus Tikoua Bur.

Ficus tikoua Bur has high slope ecological environment adaptability and garden landscape appreciation,and has great application potential.However,there are problems of less solidity.slow rooting,long germination time,low proliferation coefficient,and long time required for plant formation.This greatly limits the development utilization and promotion of the F.tikoua Bur.Therefore,the establishment of the tissue culture regeneration system and the research on drought resistance of the F.tikoua Bur is of great significance for accelerating the breeding speed of the fruit and promoting it in the garden.In this thesis,the stem segments,leaves and fruits of F.tikoua Bur.were used as research objects.By comparing different hormones and their ratios,the medium formula suitable for different stages of differentiation and differentiation of different explants was screened,and the tissue culture rapid propagation system was established.At the same time,the seedlings of F.tikoua Bur.were used as materials,and the three groups of droughts(75% water content),moderate(55% water content)and severe(35% water content)were set based on the maximum water holding capacity in the field(46.5%).The changes of morphological,physiological and photosynthetic indicators of different fruit weights were determined.The main findings are as follows:1.Establishment of tissue culture regeneration system of stem section(1)Determination of disinfectant and disinfection time:The stem section of F.tikoua Bur was treated with 0.1% HgC12(plus TWEEN-20)for 14-16 minutes,and the survival rate was 82.22%.(2)Primary culture:The optimum medium for primary culture is MS+0.5mg/L 6-BA+0.05mg/L NAA,and the germination rate was 100%.(3)Subculture:The most suitable method for subculture is to first propagate the buds on the medium of MS+0.5mg/L 6-BA+0.2mg/L NAA,and then transfer to MS+0.5mg/L 6-BA+0.1mg/L NAA.and the multiplication ratio was 2.63.(4)Rooting induction:The most suitable rooting method is to induce rooting on the medium of MS+0.1mg/L IBA+0.1mg/L NAA,and then add 0.5 mg/L IBA+1.0 mg/L NAA,the rooting rate was 46.67%,and the average number of roots was 8.2.Establishment of callus regeneration system(1)Determination of disinfectant and disinfection time:The leaves of the ground fruit were disinfected with 2% NaCIO solution for 10 minutes,and the disinfection effect was the best,and the survival rate was 50.46%.The disinfection of F.tikoua Bur.was best disinfected with 2% NaCIO solution for 14 min,and the survival rate was 96.67%.(2)Callus induction:The optimal medium for inducing shoots was MS+0.5mg/L 6-BA+1.0mg/L NAA+1.0mg/L TDZ.Callus induction ratio was 91.1%.The optimal medium for inducing leaf callus was MS+0.5 mg/L 2,4-D+0.02 mg/L TDZ,and the callus induction rate reached 90%.The optimal medium for inducing F.tikoua Bur.callus was MS+2.0 mg/L 6-BA+1.0 mg/L NAA,and the callus induction rate was 100%.(3)Differentiation of callus adventitious buds:The optimum medium for callus differentiation adventitious buds was MS+0.5mg/L TDZ+2.0 mg/L 6-BA,and the differentiation rate was 61.11%.(4)Proliferation of cluster buds:The optimal medium for colony bud proliferation is MS+0.5mg/L TDZ+1.0 mg/L 6-BA+1.0mg/L NAA,and the multiplication ratio is 6.05.(5)Adventitious bud rooting:The optimum medium for inducing adventitious bud rooting was 1/2 MS+1.0 mg/L IBA+0.1 mg/L NAA,the rooting rate was 68.52%,and the average rooting number was 10.67.(6)Refining and transplanting of tissue culture seedlings:Garden soil:perlite:vermiculite=2:1:1 is the best cultivation substrate for transplanting and domesticing,and the survival rate of transplanting can reach 86.17%.3.Drought resistance research of ground fruitThe mild drought not only inhibits the morphology of the F.tikoua Bur.,but also promotes the growth.When the F.tikoua Bur is under moderate drought stress,the plant can maintain its normal growth state,but the growth rate is slow.When the stress was severe,the growth of the F.tikoua Bur was almost stagnant.In terms of physiological characteristics,the activities of SOD,POD and proline and protein decreased with the increase of drought stress days,and the content of chlorophyll also appeared.After a short period of increase,as the light drought stress time gradually increased,the physiological indexes of the F.tikoua Bur fluctuated,but remained at a high level.From the perspective of photosynthetic characteristics,the F.tikoua Bur photosynthesis can maintain normal photosynthesis in the short-term(15d)mild or moderate stress,but its photosynthesis is significantly affected when the stress is severe for 5d.F.tikoua Bur survive under mild drought for 30 days,and can also resist moderate drought stress of 25d and severe drought stress of 10d.It shows that the F.tikoua Bur has a strong drought resistance.