| Eighteen hybrid varieties were used for isolated microspore culture in Kale.Factors influencing microspore embryogenesis,microspore plant regeneration,subculture and rootage were probed.Methods for the ploidy identification and artificial doubling for microspores-derived plants were studied.The uniformity and the horticultural characters of the DH lines and their hybrids were analysised.The aim of research is to optimize the system for isolated microspore culture and accelerate the application of the techniques in Kale breeding.Results are as follows.1.Analysis the relationship between bud form indexes and microspore development degree indicates that as bud length was between 2.5-3.49 mm and the ratio of petal to anther length was between 1/2-4/5,70%of the pollen was in the late uninucleate stage in Kale.The time is suitable for microspore culture.2.Bud pretreatment under 4℃for 24～48 hr improved the embryogenesis.3.Agarose and active carbon in the medium can influnce embryoid induction and development.The suitable content is 20mg·L-1agarose and 0.4 g·L-1active carbon.4.The appropriate content of glutamine in the medium was 0.4～0.8 g·L-1.5.Effect of Type and concentration of hormones on inducing embryo is different from different genetypes.There were no embryos in NLN-13 medium with no or only little 6-BA for "Y012".While there were embryos in NLN-13 medium with 0.1 mg·L-16-BA+0.1 mg·L-1NAA or 0.2 mg·L-16-BA+0.2 mg·L-1NAA,the frequency of embryo was 1.38 embryo/bud;It was just contrary for "Y007" and "Y017".There were more embryos in NLN-13 medium with(0.05 mg·L-1～0.2 mg·L-1)6-BA.The frequency of embryo were 1.38 embryo/bud and 1.31 embryo/bud,but no embryos on the others NLN-13 medium.6.There were fifteen varieties to obtain embryos among eighteen varieties using the opmization system of the laboratory.Rate of producing embryo was 83.33%.It was different to produce embryos during varieties.The high production was 1.75 embryo/bud in "Y009". The low production was 0.31 embryo/bud in "Y001".The microspores isolated from F2 were more easily to produce embryos than the same variety from F1.7.Transfering time influced the survival rate of embryo in solid medium.The suitable transferring time was the 25th day.The rate of embryo was 79%.The rate of brown was only 21%.So transferring embryo in time could reduce the rate of brown and raise the rate of regeneration of plant.8.The optimal medium for shoot of is "MS+2.0 mg/L6-BA+0.1 mg/L NAA +3%sucrose +0.7%agar".The rate of inducing shoot is 56.38%.9."1/2MS+NAA0.1 mg·L-1+3%sucrose + 0.7%agar" is suitable medium for rooting.The rate of rootage is 100%.10.The methods of ploidy identification of microspore-derived plant could use The method of combining with chromosome numbers,identifications of morphological,stomatal characteristics of analysis,identification of pollen vitality and self-fruitfulness ability.11.The rate of matural doubling is low in Kale.The rage is from 12%to 25%among the varieties.12.The treatment of the mixture of DMSO and colchicines on planlets could increase the producing rate of DH plants.In shoot socking research,the suitable treatment was 0.1% colchicines + 2%DMSO and 36 hours.The doubling rate was 43.75%.In the root socking research,the suitable treatment was 0.1%colchicines+2%DMSO and 4 hours.The doubling rate was 41.38%.13.DH plants which abtained in the experiment have conspicuous self-incompatibility and can be used directly as parental lines to make hybrids through combining ability test.It can leave out the castration operation and reduce the cost of seed production.14.The DH strain obtained in the experiment and the hybrid combinations developed with it were uniform.The ornamental characters were viewing and good,with great application value.
|
PDF Full Text Request