Bioscience Evidence 2024, Vol.14, No.1, 32-38 http://bioscipublisher.com/index.php/be 33 The integration of genomic tools into cassava breeding programs is essential for the improvement of this vital crop. The research aims to explore the current status and future prospects of genomic tools in cassava improvement, with a focus on how these tools can be applied to enhance yield, quality, and resistance to biotic and abiotic stresses. 1 Genetic Background and Genomic Characteristics of Cassava 1.1 Genetic diversity and genome structure of cassava Cassava, a staple crop in many tropical and subtropical regions, is renowned for its remarkable adaptability to diverse environments and its ability to thrive on marginal soils. The genetic diversity of cassava is vast, reflecting its cultivation by various cultures across numerous agroecological zones for centuries. This diversity is crucial for breeding as it encompasses a range of traits like drought tolerance, disease resistance, and varying root qualities. The cassava genome is diploid, containing 18 chromosomes, and has been estimated to be about 770 megabases in size. It is characterized by a high level of heterozygosity and significant presence of repetitive elements, which together account for nearly two-thirds of the genome. These genomic characteristics pose challenges in genome assembly and sequence analysis but are vital for understanding the genetic basis of its phenotypic traits (Elias et al., 2017). 1.2 History and current status of cassava genome research Cassava genome research has progressed significantly over the past decade. The first draft of the cassava genome was published in 2009, marking a pivotal step in cassava genomics. This initial effort provided a foundation for identifying genes associated with important traits such as starch production and pest resistance. Since then, several refined versions of the genome have been released, utilizing advances in sequencing technologies which have enabled higher resolutions of genomic structure and variation. Currently, the focus of cassava genome research is on applying genomic tools to enhance breeding efficiency. Technologies such as genome-wide association studies (GWAS) and genomic selection have become integral in identifying genetic markers linked to desirable traits. This approach facilitates the rapid selection of superior genotypes without the need for extensive field testing (Tuo et al., 2023). Moreover, the integration of functional genomics, through transcriptomic and proteomic studies, has started to elucidate the molecular mechanisms underlying cassava's responses to environmental stresses and nutritional content. This comprehensive genomic knowledge not only accelerates the traditional breeding processes but also opens up possibilities for the application of modern biotechnological techniques such as CRISPR/Cas9 for targeted gene editing. The current status of cassava genome research is therefore marked by a transition from basic genomic characterization to more applied genomic-assisted breeding and genetic engineering. This transition is supported by an ever-growing body of genomic resources and tools, promising to unlock further potential of cassava as a crop vital for food security and economic development in many developing countries. 2 Currently Applied Genomic Tools and Technologies 2.1 High-throughput sequencing technology High-throughput sequencing (HTS) technologies, including next-generation sequencing (NGS) and single-cell sequencing, have revolutionized genomic research in cassava by providing extensive data on genetic variation, gene expression, and molecular interactions. NGS platforms such as Illumina and PacBio have enabled the sequencing of entire cassava genomes and transcriptomes at a significantly reduced cost and time, facilitating a detailed understanding of the genetic makeup and variability within different cassava strains. Single-cell sequencing, although less commonly used in plants, offers unique insights into the cellular responses of cassava under various stress conditions, potentially isolating novel adaptive genetic traits (Veley et al., 2021).
RkJQdWJsaXNoZXIy MjQ4ODYzMg==