International Journal of Aquaculture, 2025, Vol.15, No.2, 76-87 http://www.aquapublisher.com/index.php/ija 77 Based on reviewing the genetic foundation of abalone's economic traits and traditional breeding experience, this study focuses on summarizing the research progress and application prospects of genome selection breeding technology in abalone, analyzing the current technical and industrialization challenges, and looking forward to the future direction of achieving the transformation of abalone breeding model through the integration of multi-dimensional technology. Through a systematic review of Chinese and foreign literature in the past five years, we hope to provide theoretical reference and practical reference for the cultivation and industrial upgrading of abalone varieties. 2 Genetic Basis and Breeding Objectives of Economic Traits of Abalone 2.1 The main economic traits of abalone and their genetic control modes The main economic traits of abalone can be categorized into three major types: yield traits, quality traits, and stress resistance traits. Yield traits include individual weight, shell length, shell height, and meat yield ratio, which directly determine aquaculture profitability. Quality traits involve appearance (e.g., shell color) and nutritional components (e.g., taurine and protein content), which are closely related to market value and consumer preferences. Stress resistance traits refer to tolerance to high temperatures, low oxygen, and disease resistance, all of which are critical for survival rate and farming stability. Most economic traits in abalone are controlled by quantitative genes, exhibiting polygenic inheritance and high environmental plasticity. Heritability estimates show substantial differences in the genetic control strength of different traits. For instance, studies on the growth traits of Haliotis diversicolor indicate that the heritability of shell length and body weight from juvenile to adult stages is moderate to moderately high (0.15~0.37). The heritability of heat tolerance traits in Haliotis diversicolor squamata (Wrinkled Disk Abalone) is moderate (0.35~0.42), while flesh quality traits such as taurine content also show moderate heritability (0.33~0.42) (Liu et al., 2023). 2.2 Conflict between genetic correlations and selection between traits In breeding practice, trade-offs are often needed between multiple target traits. When there is a positive genetic correlation between the two traits, homogeneous selection can lead to synergistic efficiency. Some studies have found that abalone shell length is significantly positively correlated with survival rate (genetically related 0.467), and the survival rate of abalone with faster growth is also relatively high. This means that certain traits can be improved simultaneously by co-selecting. However, selection conflicts occur when there is negative correlation between traits or antagonism. A typical example is the relationship between the shell color and growth of abalone: although abalone with red shell spots has ornamental or market value, its growth performance is worse than that of ordinary shell color individuals. Research on this phenomenon shows that the growth rate of red-shell abalone is significantly slower, and hybridization with ordinary strains can produce moderate-level hybrid dominance (Zhou et al., 2023). This suggests that a balanced genetic conflict is required when improving both appearance and growth traits. In addition, under the high-intensity selection of pursuing a single trait, other traits in the population may degenerate, such as one-sided pursuit of growth rate, which has led to adverse consequences such as the decrease in fertility of abalone and weakening of disease resistance. Therefore, modern breeding pays more attention to the application of comprehensive selection index and sets trait weights based on genetic correlations to avoid adverse correlation responses as much as possible. 2.3 Emerging breeding objectives: high temperature resistance, disease resistance and adaptability With the changes in breeding environment and climatic conditions, the emerging goals of abalone breeding are gradually focusing on improving environmental stress resistance and disease resistance. High temperature resistance traits are increasingly valued. The sea temperature in southern production areas such as Fujian often rises to the upper limit of abalone tolerance in summer, resulting in large-scale deaths of abalone farmed. For example, the continuous high temperature has caused the survival rate of wrinkle plates to plummet, becoming a bottleneck that restricts industrial development. Studies in recent years have shown that genomic selection has significant effect in improving the heat resistance of abalone: using about 65 000 markers to perform GS analysis
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