| The phenotypic characters of 70 ornamental crabapple varieties were investigated and measured.The contents of abscisic acid and ethylene were measured for five varieties with different fruit abscission and persistence,and the ACO1 gene(ACC oxidase gene)related to ethylene biosynthesis was cloned.The fluorescence quantitative expression difference of the ACO1 gene in different varieties and different periods were compared.The main results were as follows:1、The quantitative characters of leaves,flowers and fruits of 70 ornamental crabapple varieties were significant difference,and the coefficient of variation ranged from 9.78% to 125.2%.The biggest coefficient of variation was single fruit weight,and the smallest coefficient of variation was fruit shape index.There were diversity in flower color,flower type,flowering phenology,leaf color and fruit color among different varieties of ornamental crabapple.2、Different varieties of ornamental crabapple of fruit abscission periods were different.The earliest variety of fruit was all abscission in early August.The fruit bearing period of the five varieties can persist to March of the next year.The position of fruit abscission was different,one was from the junction of fruit stem and branch,the other was from the junction of fruit stem and fruit.3、The fruits of Malus ‘Radiant’ and Malus ‘Flame’ fell off early.The fruits of Malus ‘Donald Wyman’,Malus ‘Red Jewel’ and Malus ‘Sugar Tyme’ were persistent.In the process of fruit maturation and development,the fruit hardness of the five varieties decreased with passage of time.4、The content of abscisic acid in Malus ‘Donald Wyman’,Malus ‘Red Jewel’,Malus ‘Sugar Tyme’ and Malus ‘Radiant’ showed a trend of increasing at first and then decreasing.The ethylene content of Malus ‘Donald Wyman’,Malus ‘Red Jewel’ and Malus ‘Sugar Tyme’ showed a trend of increasing at first and then decreasing.Malus ‘Radiant’ and Malus ‘Flame’ had a high ethylene content during the period of fruit maturation and abscission.5、During fruit abscission,the expression of ACO1 gene increased significantly in the fruit of Malus ‘Flame’,but this phenomenon did not occur in Malus ‘Red Jewel’ which did not fall off.ACO1 gene may be related to fruit abscission,but it still needs to be verified in other varieties. |
