Tree Genetics and Molecular Breeding 2024, Vol.14, No.6, 295-303 http://genbreedpublisher.com/index.php/tgmb 296 includes evaluating the effectiveness of different genetic markers and their potential application in breeding programs to enhance dragon fruit production and quality. Through this meta-analysis, we seek to bridge the gap between genetic research and practical breeding applications, paving the way for more efficient and targeted breeding strategies. 2 Overview of Genetic Markers in Dragon Fruit Genetic markers are essential tools in the study and improvement of dragon fruit, aiding in the identification of genetic variations associated with yield and quality traits. These markers facilitate the understanding of genetic diversity, assist in marker-assisted selection (MAS), and contribute to the development of improved cultivars. The use of genetic markers in dragon fruit research has evolved over time, with various types being employed to address specific breeding and research objectives. 2.1 Types of genetic markers used Simple sequence repeats (SSRs), also known as microsatellites, are co-dominant markers widely used in horticultural crop improvement due to their high polymorphism and reproducibility. SSRs have been effectively utilized in the characterization of genetic diversity and the identification of quantitative trait loci (QTL) in various fruit crops, including citrus and guava, which share similar breeding challenges with dragon fruit. The development of SSR databases, such as citSATdb for citrus, highlights their utility in germplasm characterization and molecular breeding (Morillo et al., 2022; De Mori and Cipriani, 2023). Single nucleotide polymorphisms (SNPs) are another class of genetic markers that provide high-resolution insights into genetic variation. Although not explicitly mentioned in the provided data, SNPs are generally favored for their abundance and potential for high-throughput genotyping, making them suitable for detailed genetic mapping and association studies in fruit crops (Cockerton et al., 2021). Other marker types, such as amplified fragment length polymorphisms (AFLPs) and random amplified polymorphic DNA (RAPDs), have been used in the study of genetic variability and diversity. In the context of guava, sequence specific amplified polymorphism (SSAP) markers have shown higher polymorphism and intraspecific variability compared to AFLPs, indicating their potential utility in dragon fruit research for similar purposes (Maan et al., 2023). 2.2 Marker-trait associations reported Marker-trait associations are crucial for understanding the genetic basis of important agronomic traits. In guava, SSR markers have been linked to QTLs related to fruit characteristics such as pulp thickness, color, and soluble solids, demonstrating their applicability in early selection and MAS (Chen et al., 2024; Lin et al., 2024). These findings suggest that similar approaches could be applied to dragon fruit to identify markers associated with desirable yield and quality traits. 2.3 Trends in marker application over time The application of genetic markers in fruit crop research has evolved significantly, with a shift towards more informative and high-throughput markers like SSRs and SNPs. The development of comprehensive marker databases and the integration of advanced genotyping techniques have enhanced the precision and efficiency of breeding programs. This trend is expected to continue, with ongoing advancements in molecular technologies further facilitating the genetic improvement of dragon fruit and other horticultural crops (Rifat et al., 2019). 3 Yield Traits in Dragon Fruit 3.1 Genetic basis of yield-related traits The genetic basis of fruit weight and size in dragon fruit is influenced by a variety of genetic markers that contribute to the phenotypic diversity observed in different genotypes. Studies utilizing Inter-Simple Sequence Repeat (ISSR) markers have revealed significant genetic diversity among dragon fruit accessions, which is crucial for breeding programs aimed at improving yield traits such as fruit weight and size. For instance, research conducted on Hylocereus spp. in China demonstrated high polymorphism in genetic markers, indicating a broad
RkJQdWJsaXNoZXIy MjQ4ODYzMg==