title: Identification and characterization of a QTL on chromosome 2 for cytosolic glutamine synthetase content and panicle number in rice.
abstract: A quantitative trait locus (QTL) associated with the protein content of cytosolic glutamine synthetase (GS1; EC 6.3.1.2) in senescing leaves, panicle number, and panicle weight was characterized in rice (Oryza sativa L.). A near-isogenic line (NIL), C-22, developed by marker-assisted selection was grown under different nitrogen levels in the greenhouse and in a paddy field. Chromosome 2 of C-22 had an approximately 50-cM segment substituted from the Kasalath (indica) chromosome in a Koshihikari (japonica) genetic background. C-22 showed a 12-37% lower content of GS1 protein in leaf blades than Koshihikari, which was in good agreement with a QTL region positively affected by the japonica chromosome. At an early vegetative stage, C-22 had more active tillers than Koshihikari in the greenhouse. At the reproductive stage, both panicle number and total panicle weight of C-22 were significantly higher than those of Koshihikari, particularly when the plants were grown under a low-nitrogen condition. These traits of C-22 were further confirmed in a paddy field. Thus, tiller development was positively affected by the Kasalath chromosome at an early vegetative stage, which resulted in an increased panicle number and panicle weight at the mature stage in C-22. These data indicate that the target QTL (Pnn1; panicle number 1) is important in the development of tillers and panicles in rice. Linkage analyses for panicle number and ratio of developing tiller formation in the second axil (RDT) revealed that Pnn1 was delimited at the 6.7-cM region.
authors.affiliation: Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidoori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Obara
authors.forename: Tadashi
authors.initials: T
authors.lastname: Sato
authors.forename: Shohei
authors.initials: S
authors.lastname: Sasaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Kashiba
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nagano
authors.forename: Ikuo
authors.initials: I
authors.lastname: Nakamura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ebitani
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yano
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yamaya
mesh_terms: D000483:Alleles; D001483:Base Sequence; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D003600:Cytosol / Q000201:enzymology; D018744:DNA, Plant / Q000235:genetics; D005838:Genotype; D005974:Glutamate-Ammonia Ligase / Q000235:genetics*; D012275:Oryza / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D018515:Plant Leaves / Q000201:enzymology; D010940:Plant Proteins / Q000378:metabolism; D040641:Quantitative Trait Loci
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins; D005974:Glutamate-Ammonia Ligase