Genetic diversity analysis and comprehensive evaluation of cone and seed quality of Cunninghamia lanceolata

【Objective】The genetic diversity of cone and seed quality traits of different Cunninghamia lanceolata germplasms was clarified, and the high quality resources were screened to provide scientific basis for the breeding of C. lanceolata varieties and the efficient utilization of germplasm resources.【Method】The cones and seeds of 40 clones in the second-generation seed orchard of C. lanceolata in Guangxi were selected as the research objects in this study. Using variance analysis, cluster analysis, principal component analysis, 15 quality traits from three aspects(cone phenotypic traits, seed germination characteristics and seed excellence traits) were analyzed and comprehensively evaluated.【Result】 The genetic diversity index of 15 quality traits of 40 C. lanceolata clones ranged from 1.4792 to 2.0803, with an average of 1.9090. The largest genetic diversity index was empty seed rate, and the smallest was moldy seed rate. The coefficient of variation ranged from 4.55% to 120.72%, with an average of 29.60%. The largest coefficient of variation was moldy seed rate, and the smallest was fruit shape index. The heritability was between 0.366 and 0.969, with an average value of 0.843. The largest heritability was cone horizontal diameter, and the smallest was empty seed rate. Empty seed rate had significant differences among clones(P<0.05), the other 14 quality traits had extremely significant differences among clones(P<0.01). The 40 clones of C. lanceolata could be divided into four groups. Among them, group II had the best comprehensive traits, and group I had the best seed excellence traits. Principal component analysis was conducted on the quality traits of 15 C. lanceolata cones and seeds. The top eight clones with comprehensive traits were numbered as 14, 34, 28, 31, 38, 9, 29 and 27, respectively.【Conclusion】The genetic diversity of cone and seed quality traits of 40 clones in second-generation seed orchard of C. lanceolata in Guangxi is rich, and 8 clones screened can be used as excellent materials for the development, preservation and utilization of germplasm resources.