Induction And Biological Identification Of Autotetraploid Non-Heading Chinese Cabbage

This article was about the induction and identification of two kinds of tetraploid non-heading Chinese cabbage(Brassica campestris ssp.chinensis Makino,2x=2n=20)'Xiao Airen' and 'Huang Xinwu' when the colchicine concentration was 0.2%.Autotetra ploid plants were selected and identified based on morphological,anatomic,agronomic,cytological observation and flow cytometry.The tetraploid plants agronomic characters and nutritional quality of comparative analysis,and the high quality tetrploid 'Xiao Airen' and'Huang Xinwu' varieties breeding.1.0.2%concentration of colchicine were used on the growing point of the diploid non-heading Chinese cabbage 'Xiao Airen'(Brassica campestris ssp.chinensis Makino,2n=2x=20)which was in the cotyledon period by 2 times,4 times and 6 times treatment.The genetically stable tetraploid was obtained by ploidy identification,which was based on morphology,anatomy,cytology and flow cytometry means.The results showed that:the best induced mutagenesis of the tetraploid was 7.4%when the colchicine concentration was 0.20%and the processing time was six.Compared with the diploid,the autotetraploid had a significant difference in stoma,floral organ and silique,through measurement and comparison.The stomatal length and width increased by 26.9%and 39.4%,stomatal density decreased by 42.1%;The flower color of tetraploid deepened while the petal length and width,pistil and stamen length increased by 34.04%and 39.05%,26.4%and 18.3%than the diploid;the pollen grains length and width increased 18.3%and 30.6%when the shape changed from oval into a nearly obtuse brick form;the pod of tetraploid significantly increased,which was that the length and width increased,respectively,by 18.3%and 30.6%compared with the diploid;the seed diameter increased by 33.8%and the weight of 50 seeds increased by 46.5%.The No.of seeds per silique decreased by 66.7%.The flow cytometry was used to identify the ploidy of induced plants.The result suggested that the relative DNA content of diploid was 300,and tetraploid relative DNA content was 600.2.0.2%concentration of colchicine were used on the growing point of the diploid non-heading Chinese cabbage 'Huang Xinwu'(Brassica campestris ssp.chinensis Makino,2n=2x=20)which was in the cotyledon period by 2 times,4 times and 6 times treatment.The genetically stable tetraploid was obtained by ploidy identification,which was based on morphology,anatomy,cytology and flow cytometry means.The results showed that:the best induced mutagenesis of the tetraploid was 7.63%when the colchicine concentration was 0.20%and the processing time was six.Compared with the diploid,the autotetraploid had a significant difference in stoma,floral organ and silique,through measurement and comparison.The stomatal length and width increased by 37.7%and 29.1%,stomatal density decreased by 37.7%;The flower color of tetraploid deepened while the petal length and width,pistil and stamen length increased by 32.41%and 46.67%,25.0%and 15.7%than the diploid;the pollen grains length and width increased 25.4%and 37.4%when the shape changed from oval into a nearly obtuse brick form;The pod of tetraploid significantly increased,which was that the length and width increased,respectively,by 22.63%and 21.4%compared with the diploid;the seed diameter increased 35.9%and the weight of 50 seeds increased by 44.9%.The No.of seeds per silique decreased by 66.5%.The flow cytometry was used to identify the ploidy of induced plants.The result suggested that the relative DNA content of diploid was 200,and tetraploid relative DNA content was 400.3.The nutritional quality and agronomic characters were compared when both the diploid and tetraploid 'Xiao Airen' and 'Huang Xinwu' were under field conditions.The results demonstrated that:(1)Compared with the diploid,the leaf width,the the length and width of petiole,the leaf weight,the stem weight and the plot yield of the tetraploid ' Xiao Airen' performed a significant increase.The content of chlorophyll in tetraploid 'Xiao Airen' significantly increased compared with diploid.Contents of dry matter,soluble sugar and protein,organic acid,nitrate and Vitamin C in tetraploid increased 40.1%,39.3%,41.3%,29.1%,25.1%and 12.1%respectively compared to the diploid.(2)Compared with the diploid,the plant height,the the length and width of leaf,the quality of single plant and the plot yield of the tetraploid 'Huang Xinwu' performed a significant increase.The content of chlorophyll in tetraploid 'Xiao Airen' significantly increased compared with diploid.Contents of dry matter,soluble sugar and protein,organic acid,nitrate and Vitamin C in tetraploid increased by 37.4%,22.7%,30.1%,35.0%,14.3%and 20.9%respectively compared to the diploid.