Optimization For The Technical Of Isolated Microspore Culture Of Komatsuna

An ideal homogeneous inbred material needs6-8generations selfing by the conventional methods. We can acquire homozygous plant offspring through isolated microspore culture. It can not only greatly shorten the breeding process of inbred lines and new hybred varieties, but also benefit the development of the germplasm resources.There are lots of reports on the isolated microspore culture of the plants, and the concerned technology is more and more maturing. The difference of embryo rate among genotypes and low plant regeneration rate is becoming obstacles for thus technique. Therefore, the paper tries to find the factors affecting both microspore embryo rate and plant regeneration rate in of9different genotypes of Komatsuna, to establish a microspore culture system with high frequency and stability. Meanwhile, the method identifying the chromosome ploidy of regeneration plants through microspore culture is studied. The results are following:1. The effectors on the rate of microspore embryo induction:(1) Genotype is a key role on the microspore embryonic induction rate. The rate of microspore embryonic induction is greatly different from genotypes.(2) The optimum sizes of buds among the test materials are different, the optimum bud sizes are2.00～2.99mm, when the mononuclear microspore is accounted for the largest proportion.(3) The optimum sampling occasion is flowering period. The rate of microspore embryonic induction is very low at the early and late flowering periods.(4) The optimum teperature condition is4℃for1d and33℃heat shock for1d.(5) The response of plant growth regulator is greatly different from genotypes. The microspore embryonic induction rate of633is the highest when the medium with no growth regulator.; The medium combination with0.05mg·L-16-BA+0.2mg·L-1NAA is conductive to microspore embryonic induction for634and635. (6) Thirteen percent of sucrose culture medium after1d preliminary culture with17%sugar medium can increase the embryonic induction.(7) Changing a new medium after Id the treatment of0.8%colchicine can increase the embryonic induction.(8) Eight percent of mannitol or seventeen percent of sucrose in extract liquid helps the microspore embryo genesis.2. The factors of effecting plant regeneration from microspore embryo:(1) One point two percent of sugar in B5solid medium is optimal for microspore embryonic germination and regeneration.(2) The longer the cotyledon-type embryos in liquid medium, the lower the rate of embryomic regeneration.(3) AgNO3with concentration of3.0～4.0mg·L-1in medium can effectively increase the rate of embryo germination and the number of shoots per embryo.3. The results of ploidy identification of microspore-derived in Komatsuna(1) A high level of the spontaneous doubling dfficiency from microspore-derived plants was observed in Komatsuna(2).The distribution of ploidy is different from the genes. The rate of chimera is up to60%in633, whereas in607the rate of double haploid is higher, up to50%...