Systematical Research On Self-incompatibility Of Isatis Indigotica

Isatis indigotica Fort belong to IsatisL.Cruciferae.Its roots are usually called isatidis and its leaves are usually called dyers woad.Indigotica are important crops and considerably common Chinese medicinal materials,often used to treat the disease of epidemic heat syndrome,anemopyretic cold,Swelling of throat,Epidemic meningitis,encephalitis B,lung fever,parotitis and so on.It is founded that isatidis has therapeutical and apotropaic effects on the epidemic situation such as "Severe Acute Respiratory Syndrome"," bird flu" et cetera for the past few years.People have paid more and more attention to isatidis and market requirementis increasing year by year because of it's conspicuous effectiveness and hypotoxicity.Isatis indigotica Fort is cultivated extensively in China.However indigotica is allogamy crops which existing the problems:it is hard to breed seeds,availability of fine variety is scanty,colonia is serious miscellaneous in farmland.Accordingly they can directly influence the quality of isatidis and dyers woad.Self-incompatibility extensive exist in most of aerogams and it's a natural genetic mechanism that can prevent close breeding and promote cross-fertilize.According to investigation there are 50 kinds of self-incompatible plants in 57 kinds of Brassica plants.There are many investigation report about self-incompatibility of Brassica oleracea and Chinese cabbage.But there are no report about Isatis indigogitica which is the typical materials of Cruciferae.For this reason,this text investigates amphigenetic characteristicistic of Isatis indigogitica from view of reproductive biology in order to find out self-incompatible characteristicistic of Isatis indigogitica and investigate simple and effective method of overcoming self-incompatibility,meanwhile to provide feasible way of breeding seeds used self-incompatible line,and then to promote hybrid vigor breeding.The research on indigotica reproductive biology shows that:The pollen of indigotica is subproblate in equatiorial view,3-colparate in polar view,and has 3 germinal furrows.The normally ripe pollen viability is beyond 95 percents.When the pollens are cultured by 25℃stationary temperature in modified MS medium added 3mg/L Boric Acid and 20mg/L sugar,they begin germination in 1h and most of them begin germination from 5h to 7h,then their germination rates is more than 85 percents after 8h.One flower of Isatis indigotica contains 4 780 pollens and the pollen-ovule ratio(P/O) is 9 426—28 280,these above are elementary agreement with the characteristic of cross-pollination plants.Stigma receptivity is strong in bud stage and flowering season,on the opposite Stigma receptivity is rather weak in terminal florescence.The rate of fruitage is high in natural condition.But the rate is low by artificial self-pollination in full flowering stage,and it,s self-compatible index ranged within 0.08-0.14,average self-compatible index is 0.11;the self-compatible index ranged within 0.04-0.13 and the average self-compatible index is 0.078 when self-pollination in bags;the self-compatible index ranged within 0.71-0.92 and the average self-compatible index is 0.827 in bud stage.The result above shows that indigotica not only has characteristic of self-incompatibility in full flowering stage but also has characteristic of self-compatibility in bud stage.In order to prove up mechanism of self-incompatible line,the phenomenons that pollens germinate is observed.The result shows that:Self-compatible pollens begin to germinate in 1h,then the pollens permeate the wall of stigma papilla cells and grow into bottom of style, pollen tube do not stop growing until fecundatin is finished in 42h;self-incompatible pollens can hardly germinate because that callose deposition is the obstacles of taking up water and sprouting,callose begin to deposit in stigma papilla cells,callose deposit more and more soas to become callose plug in 8h.Even if a small amount of self-incompatible pollens can germinate,they wind on the surface of stigma and can not perforate into papilla cells because exist of callose.The phenomenon that pollens growth are inhibited by callose in the surface of stigma agree with characteristic of self-incompatibility system,therefore,indigotica is preliminary identified as sporophytic self-incompatible plants.Fleorescence microscope way is suitable for identifing reaction of callose because callose appear yellowish green fluorescence in light source of fluorescence.Method of aniline blue-lactic acid-phenol is suitable for observation of pollen tube growth,but the shortcoming of this method is that dyeing time effect the result of observation.The improved method of Fleorescence microscope is more suitable for observation of pollen tube growth because colour difference and contrast between pollen tubes and stigma are raher obvious.Promoting selfing breeding is the precondition to select Isatis indigotica self-incompatible line,at the same time it is the necessary guarantee for application of self-incompatible line in breeding.So the method of overcoming Isatis indigotica self-incompatibility is further researched.The investigation indicate:The index of affinity can attain 0.91 when stigma is dealed with 3%sodium chloride +0.2%borax aq sol,and microscopic findings are that growth condition of pollens on stigma is very similar with growth condition of natural pollination,but sodium chloride + borax aq sol of higher concentration can lead corollet to be dead of anhydration.The best effectiveness is that index of affinity can attain 0.92 when stigma.is dealed with 7%acetone aq sol.The stigma has feeble callose effect that also can not effect completion of ferrtilization.Index of affinity can attain 0.73 and 0.82 when stigma is dealed with 3%acetone aq sol and 5%acetone aq sol,and the effectiveness is not as good as 7%acetone aq sol;Index of affinity can attain 0.69 when stigma is dealed with 5%KDP(potassium dihydrogen phosphate) aq sol,meanwhile pollen growth and fructification are also normal;Not only index of affinity attain 0.39 when stigma is dealed with 1%ammonium sulfate aq sol,but also carpo-hull is not full and sapless yellow.Moreover ammonium sulfate of higher concentration can make the whole inflorescence wilted,even dead;The index of affinity can attain 0.34 when stigma is dealed with 1000PPM GA₃(gibberellic acid) aq sol,phenomenon on stigma is normal and carpo-hull is bigger and fuller than normal one,even one carpo-hull contain two seeds;Index of affinity can attain 0.46 when stigma is dealed with 0.1%6-BA aq sol;But index of affinity are all less than 0.15 when stigma is dealed with 0.1%serine aq so,0.1% phytolectin aq so,5%honey aq sol,and the index is close to 0.12 which is the index of control group of distilled water,in addition effectiveness is obviously.From above,it can be seen that 3%sodium chloride +0.2%borax aq sol and 7%acetone aq sol have best effects on overcoming self-incompatibility of Isatis indigotica Fort,moreover sodium chloride,borax,acetone all have extensivesource,cheap price and have no toxicity,harm, therefore they are rather feasiblefor production and practice.The research of optimal germination condition for first filial generation selfing seeds indicates that:optimal germination condition of Isatis indigotica Fort seeds without carpo-hull is that cultivativited between paper 25℃.In this condition,germination capacity is 96%,vigour of germination is 94%,all that above agree with seed vigor which are researched by the method of TTC and BTB for first filial generation selfing seeds.The seed vigor are 94%and 93%by the method of TTC and BTB.