Innovation And Evaluation Of Germplasm Of Early Flowering Tea Chrysanthemum

Chrysanthemum（Chrysanthemum morifolium Ramat.）is a perennial plant of Compositae,also known as"Jin Ying"and"Shou Ke"in China.Besides its ornamental importance,chrysanthemum is widely cultivated for drinking,medicine,and food consumption.As the demand for healthy produce increases and more diversified,the existing varieties of tea chrysanthemum simply cannot meet this demand.Breeding tea chrysanthemum varieties with early flowering,more appealing appearance,better taste,stronger resistance to stress as well as a higher content of effective components has become an urgent goal for the tea chrysanthemum industry.At present,the lack of early flowering varieties has severely limited the development of the tea chrysanthemum industry in the north of Jiangsu and Anhui as well as northern China.In this study,11 tea chrysanthemum varieties including the early flowering cultivar’Qi Yue Bai’and the high-quality cultivar’Huang Ju’were used as parents to construct hybrid combinations to investigate the parental as well as their hybrid progenies’four primary characters,such as agronomic traits,seedling resistance,sensory quality and content of effective components.A total of 21indexes were evaluated,including full bloom period,fresh flower diameter,dry flower diameter,dry flower weight,ray flower number,inflorescence number,yield dry weight,plant height,crown diameter,drought tolerance,waterlogging tolerance,flower shape,flower color,flower scent,soup flower,soup color,flower taste,total flavonoids content,chlorogenic acid,luteolin glycosides,and Isochlorogenic acid A.Membership function value analysis,hierarchical analysis and cluster analysis were carried out on the four primary characters of the tea chrysanthemum to select new varieties with early flowering,high yield,strong resistance,and good quality.The results are as follows:1.In 2019,fresh flower diameter,dry flower diameter,dry flower weight,and ray flower number of the 140 preliminarily selected F₁hybrid progenies of the tea chrysanthemum during the full bloom period were investigated.Then,the hierarchical analysis and K-means cluster analysis were further used to evaluate these 140 plants,and89 superior hybrid progenies were selected.In 2020,the selected 89 F₁progenies and 11parental cultivars were investigated for 9 field agronomic traits,including full bloom period,fresh flower diameter,dry flower diameter,single flower dry weight,ray flower number,dry yield per mu,inflorescence number,plant height and crown diameter.After evaluation and grading,15 early flowering tea chrysanthemum progenies with best field agronomic traits were obtained,and their identities were S28-1,D18-5,F14-1,I24-3,N4-6,E89-1,PK1,PK17,GH3,N17-6,D57-1,I6-4,E62-3,PK16,PK19.2.The drought tolerance and waterlogging tolerance of 89 selected lines and 11parents were identified by plug natural drought method and pot simulated flooding method.The drought tolerance and waterlogging tolerance of plants were graded by membership function value method.Six high drought tolerant lines,13 drought tolerant lines,9 high waterlogging tolerant lines and 29 waterlogging tolerant lines were selected.Furthermore,15 excellent lines with strong comprehensive resistance to drought and flood were screened out,which were QS4,QS2,QS3,QS1,S17-3,PK17,PK4,GH12,GH31,GH9,I16-3,QS5,Z5,GH4,I18-5.3.The appearance quality of the 89 hybrid lines and 11 parents of tea chrysanthemum was evaluated for flower shape,flower color,scent,soup flower,soup color,and taste.56materials were selected by preliminary evaluation,and 25 hybrid lines which were E88-2,M18-2,N4-6,N19-6,QS1,E70-5,N8-1,N17-6,E5-3,S2,E29-1,E46-6,D18-5,E2-3,K38-2,K49-1,S22-5,I18-5,GH3,E42-3,S1,QS7,E1-1,S11-2,G14-5 with better sensory quality were obtained by further synthesizing the results of two years’re-evaluation.Specifically,the sensory quality of E88-2,M18-2,N4-6 was even better than that of‘Huang Ju’.4.The total flavonoids,chlorogenic acid,luteolin glycosides,and Isochlorogenic acid A content in the 89 hybrid lines and 11 parents of tea chrysanthemum were determined.There were 8,11,3 and 8 lines with the highest content of four components and higher than the highest content of their parents,respectively.The K-means cluster analysis method was used to divide the comprehensive score into three grades,and 16 hybrid lines with better comprehensive characters of effective component content were selected,which were GH12,GH14,D14-1,E47-3,E5-3,F14-1,GH17,GH23,GH3,GH31,HJ1-4,I7-5,N4-6,QS5,S2,PK2。5.A hierarchical structure model was utilized to evaluate the 89 hybrid lines and 11parents of tea chrysanthemum from four aspects of field agronomic traits,resistance,sensory quality and effective components.K-means cluster analysis was used to grade tea chrysanthemum materials,and 29 superior hybrid progenies were selected,which were GH3,N4-6,D18-5,N17-6,S11-2,E29-1,S28-1,E47-3,M18-2,F14-1,K38-2,F4-4,I7-5,E70-5,N8-1,QS2,QS3,I24-3,D57-1,E88-2,PK19,HJ1-4,I6-4,GH8,PK16,G14-5,S29-1,E89-1,QS1.