Techniques For Microspore Embryogenesis And Plantlet Regeneration In Chinese Cabbage

Thirty varieties and strains were used for isolated microspore culture in Chinese Cabbage. The researches of include influence factors to microspore embryogensis, the methods of increasing microspore plant getting rate and the ploidy of microspore plant and ploidy identification method. The main results were as follows:1. In microspore embryogenesis capacity, there is very great difference in each genotype. According to the generation of the microspore embryo, we divide materials into three kinds, which are the easily yielding embryos, the yielding embryos ability lower and difficult in producing the microspore embryos.2. Different genotype materials microspore development synchronous has greater difference. Relationship of microspore development degree is different with variety of Chinese Cabbage. The suitable bud index of most varieties as follows: bud size is 2.5-3.5mm,the suitable petal / anther is 2/3-1.3. Different kinds and concentrations of hormones can affect embryo emergence and embryo develop. Low density of ctytokinin can promote the embryogenesis and improve the frequency of microspore embryogenesis. The high contents of ctytokinin have inhibition to production of microspore embryo. The ctytokinin is disadvantageous to development of the microspore embryo. And the ctytokinin of the high content usually makes the microspore embryo develop to the deformity. Auxin has inhibition to embryo emergence, but has the function that promotes normal development of embryo.4. The plantlet regeneration rate is closely related to embryo development period. The bigger the embryo is, the easier to become shoots. And the shoots mostly come from the ripe cotyledon embryos.5. 1.2% agar of medium is the most suitable agar content for microspore embryo becoming shoots culture of Chinese Cabbage. The active carbon of 200mg/l in medium is favorable to the microspore embryo becoming shoots.6. Haploid, diploid, triploid, tetraploid and chimaera are different in proportion among different genotype material, and the naturally double rate have remarkable differences between different genotypes.7. Counting the number of the chromosomes is the most reliable method in testing the ploidy level of Chinese Cabbage. And the results showed FCM is an effective method of estimating ploidy level. The stomata characteristic value and plant ploidy have certain relationship. Because the size of the stoma cell, chloroplast count and stomata density value in different ploidy plants have certain overlay, and have chimaera in colony, so the characteristic value of stomata is difficult to regard as the index of ploidy qualification of Chinese Cabbage.