title: Application of an Effective Statistical Technique for an Accurate and Powerful Mining of Quantitative Trait Loci for Rice Aroma Trait.
abstract: When a phenotype of interest is associated with an external/internal covariate, covariate inclusion in quantitative trait loci (QTL) analyses can diminish residual variation and subsequently enhance the ability of QTL detection. In the in vitro synthesis of 2-acetyl-1-pyrroline (2AP), the main fragrance compound in rice, the thermal processing during the Maillard-type reaction between proline and carbohydrate reduction produces a roasted, popcorn-like aroma. Hence, for the first time, we included the proline amino acid, an important precursor of 2AP, as a covariate in our QTL mapping analyses to precisely explore the genetic factors affecting natural variation for rice scent. Consequently, two QTLs were traced on chromosomes 4 and 8. They explained from 20% to 49% of the total aroma phenotypic variance. Additionally, by saturating the interval harboring the major QTL using gene-based primers, a putative allele of fgr (major genetic determinant of fragrance) was mapped in the QTL on the 8th chromosome in the interval RM223-SCU015RM (1.63 cM). These loci supported previous studies of different accessions. Such QTLs can be widely used by breeders in crop improvement programs and for further fine mapping. Moreover, no previous studies and findings were found on simultaneous assessment of the relationship among 2AP, proline and fragrance QTLs. Therefore, our findings can help further our understanding of the metabolomic and genetic basis of 2AP biosynthesis in aromatic rice.
authors.affiliation: Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
authors.forename: Farahnaz Sadat
authors.initials: FS
authors.lastname: Golestan Hashemi
authors.affiliation: Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia; Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
authors.forename: Mohd Y
authors.initials: MY
authors.lastname: Rafii
authors.affiliation: Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia; Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
authors.forename: Mohd Razi
authors.initials: MR
authors.lastname: Ismail
authors.affiliation: Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia; Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
authors.forename: Mahmud Tengku Muda
authors.initials: MT
authors.lastname: Mohamed
authors.affiliation: Bioscience and Agrotechnology Division, Malaysian Nuclear Agency, Bangi, 43000, Kajang, Selangor, Malaysia.
authors.forename: Harun A
authors.initials: HA
authors.lastname: Rahim
authors.affiliation: Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia; Bangladesh Rice Research Institute (BRRI), Gazipur, 1701, Bangladesh.
authors.forename: Mohammad Abdul
authors.initials: MA
authors.lastname: Latif
authors.affiliation: Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
authors.forename: Farzad
authors.initials: F
authors.lastname: Aslani
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D057225:Data Mining; D015233:Models, Statistical; D012275:Oryza / Q000737:chemistry / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics; D011758:Pyrroles / Q000737:chemistry / Q000378:metabolism*; D040641:Quantitative Trait Loci
chemical_list: D010940:Plant Proteins; D011758:Pyrroles; C426303:2-acetyl-1-pyrroline