The wild relatives of rice (Oryza sativa L.) are useful sources of alleles that have evolved to adapt in diverse environments around the world. Oryza rufipogon, the known progenitor of the cultivated rice, harbors genes that have been lost in cultivated varieties through domestication or evolution. This makes O. rufipogon an ideal source of value-added traits that can be utilized to improve the existing rice cultivars. To explore the potential of the rice progenitor as a genetic resource for improving O. sativa, 33 chromosome segment substitution lines (CSSLs) of O. rufipogon (W0106) in the background of the elite japonica cultivar Koshihikari were developed and evaluated for several agronomic traits. Over 90% of the entire genome was introgressed from the donor parent into the CSSLs. A total of 99 putative QTLs were detected, of which 15 were identified as major effective QTLs that have significantly large effects on the traits examined. Among the 15 major effective QTLs, a QTL on chromosome 10 showed a remarkable positive effect on the number of grains per panicle. Comparison of the putative QTLs identified in this study and previous studies indicated a wide genetic diversity between O. rufipogon accessions.
BackgroundGlabrousness is an important agricultural trait for the practical breeding of rice. In this study, depilous (dep), the gene responsible for glabrous leaves and glumes of rice was identified by map-based cloning.ResultsThe dep gene encodes a WUSCHEL-related homeobox 3B that was fine-mapped to a 22-kb region on the short arm of chromosome 5 using progenies derived from crosses between Koshihikari (pubescent) and GLSL15, an Oryza glaberrima chromosome segment substitution line (glabrous). Complementation tests confirmed the conditioning of the glabrous phenotype by the dep gene. Phylogenetic analysis showed that dep groups with the WOX3 family of plant-specific homeobox transcription factors that are involved in regulating lateral organ development. Localization of dep in the nucleus indicates the function of the gene as a transcription factor. Spatial expression of the gene was observed in the base of young shoots, the leaf sheath, midrib, young roots and nodal structures.ConclusionThe identification and cloning of dep will not only provide basis for future research on the elucidation of the molecular mechanisms underlying trichome formation in rice but will also aid in breeding programs for the development of glabrous varieties.Electronic supplementary materialThe online version of this article (doi:10.1186/1939-8433-5-28) contains supplementary material, which is available to authorized users.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.