Study On Polyploid Mutation And Preliminary Identification Of Purple Cabbage

Purple cabbage(Brassica campestris L.ssp.chinensis var.Purpurea Tsen et Lee),also known as red cabbage,large stock,Purple cabbage(2n=2x=20,x=10)belongs to the Cruciferae Brassica species.Yizheng Purple Flowering Chinese Cabbage is a specialty of Yizheng City,Jiangsu Province.It was awarded the title of ’China National Geographical Indications Product’ in 2020.At present,it is mainly left by farmers themselves,which leads to the uneven quality of the germplasm resources of Yizheng Purple Caitai.At the same time,as a variant of non-heading Chinese cabbage,the genetic basis of Purple Caitai is narrow.Therefore,it is urgent to strengthen the innovation of Purple Caitai germplasm resources.In this study,colchicine was used to treat the germinated seeds of Yizheng Purple Flowering Stalk to induce tetraploid plants,and new germplasm resources of Purple Flowering Stalk were created through screening and identification,in order to obtain new varieties of Yizheng Purple Flowering Stalk with excellent traits and strengthen the protection of local varieties.The test results show that:1.With the increase of colchicine concentration and the extension of treatment time,the emergence rate,true leaf rate and survival rate of mutant plants showed a downward trend,and the harm caused by seed germination was also greater.The concentration of colchicine treatment was 0.03%,and the treatment time was about 8 hours.The mutation rate of plant mutation was 2.34%.2.In this experiment,20 diploid chromosomes and 40 tetraploid chromosomes were found under the microscope.There were significant differences in morphological characteristics between the diploid mutant plants of Purple Flowering Sprouts induced by colchicine and the diploid of Purple Flowering Sprouts,among which the changes of floral organs and siliques were the most obvious.The results showed that the size of corolla,stigma and petals of tetraploid plants were significantly larger than that of diploid plants.The chloroplasts in guard cells increased and stomatal density decreased.Pollen microscopic observation and viability test results table.3.The leaf width,maximum leaf weight,petiole width,petiole thickness,bolting diameter and bolting weight of tetraploid plants were higher than those of diploid plants,while the plant height,expansion,maximum leaf length,bolting number,bolting length and basal leaf number were lower than those of diploid plants.The yield of tetraploid Purple Flowering Stalk was higher than that of diploid.4.Compared with diploid plants,the contents of chlorophyll,water content,soluble protein,soluble sugar,vitamin C and anthocyanin in tetraploid plants were significantly increased,while the content of crude fiber was significantly decreased.