| In order to establish an efficient technique system of isolated microspore culture in radish and accelerate the process of breeding materials purity, isolated microspore culture was performed using 19 varitys of radish.some factors was studied on embryoid induction, development and plantlet regeneration. At the same time, the methods of ploidy identification for microspore-derived plants and doubling techniques for haploid plantlets were studied. Meanwhile, horticulture characters of regeneration plants were investigated and valued in the study. The results are as follows:1.There were differernt induction rates in different varities. 13 genotypes of 19 got embryoid successfully in the research. The highest embryo yield was" Nau-lltcx-06" with 10 embryos per bud.2.The suitable sampled bud was one of the key factors affecting embryoid induction of radish. For most varieties, microspores in buds that was 6/7-8/7(petal/anther) were optimal for culture in radish. Most microspores round in shape were proper for induction.3. Active carbon with low concentration can promoted induction rate of embryoid,while high concentration active carbon has opposite effect.4.The results showed that 6-BA with low concentration can promote embryoid induction . It stimulated cell division. While 6-BA with high concentration had opposite effect.5.Pretreatment in 4℃low-temperature couldn't increase the induction rate of microspore-derived embryos,but it could keep material fresh for period of time. While keeping for 5-6 days in 4℃, the frequence of microspore-derived embryos brought down obviously, the result was that most of pollens losed activity through microscope.6. Pretreatment in 33℃high-temperature could change the developmental direction and made it from gametal developmental path to sporophyte developmental path. Meanwhile it could make microspores keeping higher vitality and stimulate cell division. The optimal time was 48 hours.7. As a whole ,the sample buds in flourishing florescence got the highest embryo yield.8. The plantlet regeneration was closely related to the growth of embryos. The bigger the embryo was, the easier to become seedlings. And the seedlings mostly came from Cotyledon-shaped embryos. The abnormal embryos can't become seedlings.9. "MS+NAA0.2mg·L-1 +3%sucrose+0.7%agar" was optimal culture medium for rootage of radish, seedling became thick and strong. Some seedlings couldn't take root for the first time,they needed took root for another time. The survival rate of microspore-derived plantlets could reach 90%-100% on condition that there were appropriate temperature, moisture and illumination.10. The rates of haploid, diploid, polyploid coming from different genotype were different. The rate of spontaneous diploidization was different notably among varieties .11 .Counting the number of the chromosomes was the most reliable method in testing the ploidy level of radish. And the results showed FCM was a fast mensuration.
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