CGG_2024v15n2

Cotton Genomics and Genetics 2024, Vol.15, No.2, 93-102 http://cropscipublisher.com/index.php/cgg 95 Figure 1 Genetic diversity and introduction history of Gossypium barbadense (Adopted from Wang et al., 2022) Image caption: (a) The upper panel shows a neighbor-joining tree of 365 G. barbadense and five Gossypium hirsutumaccessions constructed using 252 609 SNPs. (b) The left panel shows the dispersal route of G. barbadense among the major cultivation regions according to the literature. (c) The right panel indicates the genomic components of the four groups in the major cultivation regions. (d) Genome-wide averages of linkage disequilibrium (LD) decay in three cultivar groups. (e) Genetic diversity and population differentiation across four groups. Values in the circles represent the nucleotide diversity (π), and the values between the groups indicate population differentiation (FST). The cultivars shown include all the accessions in groups G2, G3, and G4 (Adopted from Wang et al., 2022) 3 Mechanisms of Interspecific Introgression 3.1 Genetic basis of introgression Interspecific introgression in Gossypium species involves the transfer of genetic material from one species to another through hybridization and backcrossing. This process can significantly alter the genomic architecture of the recipient species, leading to increased genetic diversity and the introduction of beneficial traits. For instance, introgression from G. hirsutum to G. barbadense has been shown to reorganize the genomic structure of G. barbadense, contributing to population divergence and agronomic trait variation (Wang et al., 2022). Similarly, the introgression of chromatin from G. tomentosum into G. hirsutum has been studied to understand the

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