Plant Gene and Trait 2024, Vol.15, No.5, 230-242 http://genbreedpublisher.com/index.php/pgt 235 enhances our understanding of the genetic architecture underlying grain shape and aids in the development of improved rice varieties with desirable grain characteristics. Figure 2 Manhattan plot and Q-Q plot (Adopted from Meng et al., 2022) Image caption: (A) 2018 GA’s GL Manhattan and Q-Q images. (B) 2018 GA’s GW Manhattan and Q-Q images. (C) 2017 EZ’s GLWR Manhattan and Q-Q images. (D) 2018 GA’s GC Manhattan and Q-Q images. The red arrow indicates the location of the gene. In the upper right corner is the SNP density indicator band, and different colors represent different SNP distribution densities. Gongan/GA, Ezhou/EZ (Adopted from Meng et al., 2022) 6 Key Findings on the Genetic Basis of Palatability 6.1 Major genes and QTLs identified Recent studies have identified numerous QTLs and genes associated with rice grain shape and palatability, with several key genes cloned and fined-mapped, such as GS3, GW5, and qSW5 (Huang et al., 2013). GWAS have revealed several novel QTLs, such as qTGW3.1, qTGW9, and qTGW11 for grain weight, and qGL4/qRLW4, qGL10, qGL11, and qRLW1 for grain shape (Niu et al., 2020). Additionally, 39 important QTLs were identified in a study involving 623 indica rice cultivars, including three cloned genes (GS3, GW5, OsDER1) and seven new candidate genes (Meng et al., 2022). Another study identified 38 significant loci for grain shape-related traits, with key genes like GS3andqGL3 on chromosome 3, and TGW6 andGW6a on chromosome 6 (Lv et al., 2019). 6.2 Functional analysis of palatability genes Functional analysis of these genes has provided insights into their roles in determining grain shape and palatability. For example, the gene qGL1.3, a major QTL for grain length, was fine-mapped to a 350 kb region on chromosome 1, elucidating significant phenotypic variation in grain length and weight (Zhou et al., 2019). Similarly, the QTL cluster qLWR-12c/qGW-12 was validated across multiple environments, with candidate genes identified within a 431 kb interval (Kang et al., 2021). These functional analyses are crucial for understanding the biochemical pathways and molecular mechanisms underlying grain shape and palatability. 6.3 Comparative genomics of palatability traits Comparative genomics has been instrumental in identifying and validating QTLs across different rice populations and environments. For instance, a study using a doubled haploid population and Kompetitive Allele-Specific PCR (KASP) markers identified QTLs like qGLE-12-1 and qGLE-12-2 on chromosome 12, and qGTE-3-1 on chromosome 3, which were co-detected by both linkage mapping and GWAS (Kang et al., 2020). Another study
RkJQdWJsaXNoZXIy MjQ4ODYzMg==