International Journal of Marine Science, 2025, Vol.15, No.1, 1-14 http://www.aquapublisher.com/index.php/ijms 10 Figure 2 Pedigromics (Adopted from Kube et al., 2023) Image caption: A random sample of 3 646 H. rubra, 3157H. leavigata and 2 967 hybrid progeny with total weight at 2.5 years plus their ancestor are represented in a. while 2 967 hybrid progeny and their 64 H. leavigatasires and 46H. rubra dams are represented in b. Each node represents one animal from the population. The node colours are black for H. rubra, green for H. leavigata and orange for hybrid and their size are based on total weight at 2.5 years. Male, female, and unknown sex are squares, triangles, and diamonds, respectively. The connection line (edge) colour is blue for progeny and sire and pink for progeny and dam (Adopted from Kube et al., 2023) 6 Applications in Conservation and Breeding 6.1 Identification of genetic markers for assisted selection With the advancement of abalone genome research, a large number of genetic markers and functional genes have been identified, which can be used to accelerate the molecular breeding process of abalone. Traditional abalone breeding is mainly based on phenotypes such as growth rate and survival rate, which has a long cycle and high cost. Based on whole genome data, we can now develop high-density molecular markers (such as SNP chips) for whole genome selection breeding. For example, the research team of Xiamen University developed the abalone 40K breeding chip using the whole genome sequence of the wrinkled abalone, implemented genomic selection for growth and stress resistance traits, and greatly improved the breeding efficiency (Liu et al., 2022; 2024). Genomic markers can also assist in parentage identification and pedigree construction, solving the problem of difficult pedigree tracking in large-scale artificial breeding of abalone. In this study, we identified several molecular markers associated with traits. For example, specific loci related to shell color and shell thickness were found, which can be used to breed strains with bright shell color and excellent shell shape. For example, the identification of alleles significantly associated with high temperature resistance survival rate can be used to screen heat-resistant individuals in the high-temperature breeding environment in the south. Incorporating these genomic markers into the breeding program can select potential excellent individuals in advance at the larval stage or even the fertilized egg stage, thereby shortening the generation interval and increasing genetic gain. Molecular markers also help maintain the genetic diversity of the cultured population. Long-term artificial breeding of abalone is prone to inbreeding and germplasm degradation. Monitoring the allele richness and inbreeding coefficient of the population through molecular markers can guide parent selection to avoid excessive inbreeding. Genomic marker technology provides new tools and ideas for abalone molecular breeding. The transition from empirical breeding to data breeding will effectively improve the speed and accuracy of abalone breeding. Looking to the future, with the reduction of sequencing costs and the maturity of analytical methods, genomic selection breeding is expected to be widely used in marine aquaculture shellfish such as abalone. 6.2 Whole-genome insights into hybrid vigor and disease resistance Hybridization between different species or strains of abalone often produces hybrid vigor. For example, the hybrid offspring of green abalone and black abalone show faster growth and stronger stress resistance. Using genomic
RkJQdWJsaXNoZXIy MjQ4ODYzNA==