Preliminary Study Of DH Groups' Construstion And Physiological And Biochemical Index And Agronomic Traits

Taking Xiangyan3 seedling as the experimental materials, using colchicines doubling treatment method,28 DH plants were successfully obtained through the plant ploidy identification. This experiment has preliminarily constructed the tobacco's DH breeding technological system, and conducted the technical exploration for the usage of DH technology in the breeding of tobacco varieties. The result indicates that:1 The most suitable concentration for doubling treatment of the Xiangyan3's haplobiont was 750mg/L×48h, which had a higher surviving rate, transplanting rate and doubling rate; the doubling treatment materials'field fruiting and seeding situation indicates that:to the identification of the ploidy of tobacco materials, guard cells chloroplast' stomata counting method and flow cytometer assay have high accuracy, while leaves' stomatal size and density observation method are less accuracy.2 The tobacco quality related DH plants' physiological and biochemical indexes(Reducing sugar, moisture content, potassium ion, soluble protein, soluble sugar, nicotine, chlorophyll, total nitrogen, superoxide dismutase (SOD) and nitrate reductase) are measured and compared. Based on Multi Objective Optimization Method, DH 1,2 and 4 plants are preliminarily selected which are most similar to the xiangyan3.3 The main agronomic traits (plant height, stem diameter, internodes length, leaf number, maximum leaf area) of the DH groups, which are in the root spreading stage or initial fast growing period, are measured and compared in 30,37,44,51 days after transplanting. Based on Multi Objective Optimization Method, DH 2,3,5,7,8 groups are preliminarily selected which are most similar to the Xiangyan3.Comparing both physiological and biochemical indexes and agronomic traits, the fact that DH2 plant is similar to or better than Xiangyan3 is preliminary confirmed, and could be taken as the key experimental material of the tobacco cultivation in future, and set up the foundation for the usage of DH technology in the variety improvement of Xiangyan3 tobacco.