The Creating Of New Germplasm Of Autotetraploid Non-heading Chinese Cabbage And Radish

In the study,the diploid plants of non-heading Chinese cabbage(Brassica campestris ssp.chinensis Makino,2x＝2n＝20)’Chao Huayihao’and radish ’Man Tanghong’ were used as materials,induced by treating the growing point of seeding with 0.2%colchicine.The autotetraploid plants were selected and identified based on the characteristics of morphology,anatomic and cytology(DNA content determinated by flow cytometry instrument and chromosome ploidy identification).Then the agronomic characters and nutritional quality were determinated and compared between diploid and tetraploid.The purpose was to obtain the autotetraploid plants which were with high quality.The results were as follows:1.Diploid plants of non-heading Chinese cabbage were induced by colchicine to craet new germplasm having high quality and high yield.The stem tip growing point of diploid non-heading Chinese cabbage were dripped with 0.2%concentration of colchicine for 3,4 and 5 times,respectively,then identificated and selected by morphology,anatomy,cytology and flow cytometry means.The results showed that:when the colchicine concentration was 0.2%and the processing time was four,the most induced mutagenesis of the tetraploid was 6.44%.Compared with diploid plants,autotetraploid plants had significant differences on plant size,leaf,Stoma,pollen grains,floral organ,seed and silique.The stomatal length and width increased by 37.15%and 26.31%,stomatal density decrease by 37.84%.The floral organ of tetraploid largenner while the pistil and stamen length,petal length and width increased by 11.22%and 21.79%,5.79%and 31.57%than the diploid.The pollen grains length and width increased 22.77%and 35.68%while the shape changed from oval into a nearly obtuse brick form;The silique of tetraploid obviousiy increased,which was that the length and width increase,respectively,by 20.69%and 16.51%.Meanwhile,the weight of 100 seeds increased by 20.59%.However,the maturing rate of tetraploid decreased and the NO.of seeds ten siliques decreased by 51.49%.Flow cytometry made clear that DNA relative concent of diploid(2n＝2x＝20)was at 200,and tetraploid(2n＝4x=40)was at 400.The result of observation of root tip chromosomes showed that chromosome number of diploid was 2n=2x＝20,tetraploid was 2n=4x=40.2.The stem tip growing point of diploid radish ’Man Tanghong’ were dripped with 0.2%concentration of colchicine for 3,4 and 5 times,respectively,then identificated and selected by morphology,anatomy,cytology and flow cytometry means.The results showed that:when the colchicine concentration was 0.2%and the processing time was four,the most induced mutagenesis of the tetraploid was 4.79%.Compared with diploid plants,autotetraploid plants had significant differences on plant size,leaf,stoma,pollen grains,floral organ,seed and silique.The stomatal length and width increased by 64.17%and 53.77%,stomatal density decreased by 35.33%.The floral organ of tetraploid largenner while the pistil and stamen length,petal length and width increased by 5.19%and 22.02%,25.41%and 35.63%than the diploid.The pollen grains length and width increased 18.82%and 45.02%while the shape changed from oval into a nearly obtuse brick form;The silique of tetraploid obviously increased,which was that the length and width increase,respectively,byl 1.77%and 37.28%.Meanwhile,the weight of 100 seeds increased by 2.73%.However,the maturing rate of tetraploid decreased and the NO.of seeds ten siliques decreased by 46.52%.The result of flow cytometry identification displayed that diploid DNA relative concent was in 200,and tetraploid was in 400.3.The nutritional quality and agronomic traits were compared when both the diploid and tetraploid ’Chao Huayihao’ and ’Man Tonghong’ were under same field condition.The results demonstrated that:Compared with the diploid,the tetraploid ’Chao Huayihao’ plants had better agronomic characters,leaf length,leaf width,leaf weight,single petiole weight and the plot yield performed a significant increase.The content of dry matter,soluble sugar,soluble protein and Vitamin C of tetraploid plants increased by 25.72%,34.39%,12.58%and 19.23%respectively compared to the diploid.Compared with the diploid ’Man Tanghong’,the leaf length,leaf width,stem base width,root length and root weight increased by 16.77%,23.25%,15.41%,24.47%and 26.89%respectively.The plot yield of the tetraploid plants increased 26.92%.The content of soluble sugar and soluble protein of the tetraploid increased by 23.81%and 20.65%separately than that of the diploid.