Comprehensive Evaluation and Selection of Hybrid Offsprings of Early Flowering Spray Outdoor Chrysanthemum
[Objective]The aim of this study was to establish a comprehensive evaluation system for early flowering garden chrysanthemums,and to select plant lines with flowering periods from mid-September to mid-October,of which flower colors were close to pure red or yellow with novel flower type,round plant shape and excellent comprehensive performance to enrich ornamentals for early autumn festivals in Northen China,so as to provide breeding materials and selection methods for further breeding of early flowering garden chrysanthemum.[Method]Using 3 early-flowering parents and 1 high double-flowering parent with bright color of small flowered chrysanthemum and 25 asexual hybrid progenies as test materials,30 original traits were observed from 5 aspects,including flower color,flowering period,flower type,plant type,and leaf type.The selected 18 key traits were used as evaluation factors,and then a comprehensive evaluation system was established using Analytic Hierarchy Process and K-Means clustering analysis to conduct the comprehensive screening of hybrid lines.[Result]The weight values of each trait of analytic hierarchy process were determined with the breeding objectives of early flowering,round flower type,and stable red and yellow flower color.Among them,the weight value of the initial flowering time(0.1817)was the largest,followed by the flower color stability(0.1695),the number of flowers per plant in the full flowering period(0.1383),the flowering duration(0.1301),the flower color suitability(0.0565),the flower uniformity in the full flowering period(0.0565),the inflorescence diameter(0.0539),and the number of ligulate flowers(0.0574).The 29 materials were divided into 3 grades by K-Means clustering analysis:10 in grade Ⅰ,11 in grade Ⅱ,and 8 in grade Ⅲ,accounting for 34.38％,37.93％and 27.59％,respectively.The traits of the hybrid progeny were widely separated,and the flower color,flower type,and plant type all showed transgressive traits,but the flowering period was still the earliest in the two early flowering parents,which was in line with the previous studies that the flowering period was a quantitative trait controlled by multiple genes.Therefore,the early flowering breeding still needs to screen parents and increase the resources of open-field small chrysanthemums that can be used in early autumn.[Conclusion]This evaluation method integrated the advantages of various evaluation systems,characterized the traits observed in the field with quantitative results,and conducted hierarchical analysis and evaluation guided by breeding objectives,which provided a quantitative method for comprehensive evaluation and screening of excellent varieties of early flowering garden chrysanthemum.The data analysis results indicated that the evaluation system established in this study could effectively evaluate and screen early flowering garden chrysanthemums,providing a reliable method for the breeding of new varieties of early flowering garden chrysanthemums,and helping to improve the efficiency of selecting excellent germplasm for future breeding project.Finally,10 early flowering garden chrysanthemum strains with excellent ornamental traits were selected,which could be used as new varieties or strains and also as further breeding materials.
万方数据
维普
