Breeding and genetic stability evaluation of the new Saccharina variety 'Ailunwan' with high yield

摘要

Targeted selection and continuous self-crossing were utilized to breed a new Saccharina variety. After five-generation selection breeding, the new high-yield variety "Ailunwan" with stable genetic traits was obtained. Blade length, width, thickness, and fresh weight of variety "Ailunwan" were increased by 20.2, 11.0, 49.5, and 27.3 %, respectively, and the dry matter content increased by 11.8 % compared to the control (a widely used commercial variety). Frequency distributions and coefficients of variation of blade length, width, and fresh weight are discussed, and results showed that variety "Ailunwan" had more excellent traits and lower genetic variation than the control. Grey relational analysis of fresh weight-related traits showed that each related trait was in the same correlation order both in the fourth and in the fifth generations of "Ailunwan." On the basis of sequence-related amplified polymorphism (SRAP) analysis, the fifth generation of "Ailunwan" had the lowest gene diversity (H = 0.234) compared to the other five varieties including "Zaohoucheng" (H = 0.324), "Dongfang No. 2" (H = 0.260), "Dongfang No. 3" (H = 0.265), "Pingbancai" (H = 0.249), and the control (H = 0.270), which displayed the advantage of genetic stability. Unweighted Pair Group Method with Arithmetic Mean (UPGMA) cluster analysis based on SRAP marker also revealed that variety "Ailunwan" can be distinguished from other cultivation varieties in China and its genetic structure is relatively stable.