Obara Mitsuhiro, Sato Tadashi, Sasaki Shohei, Kashiba Kenji, Nagano Atsushi, Nakamura Ikuo, Ebitani Takeshi, Yano Masahiro, Yamaya Tomoyuki
Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidoori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan.
Theor Appl Genet. 2004 Dec;110(1):1-11. doi: 10.1007/s00122-004-1828-0. Epub 2004 Nov 10.
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.
在水稻（Oryza sativa L.）中鉴定出一个与衰老叶片中胞质谷氨酰胺合成酶（GS1；EC 6.3.1.2）的蛋白质含量、穗数和穗重相关的数量性状位点（QTL）。通过标记辅助选择培育的近等基因系（NIL）C-22在温室和稻田的不同氮水平下种植。C-22的第2号染色体在粳稻品种越光的遗传背景下，有一段约50厘摩的片段被来自籼稻品种Kasalath的染色体所取代。与越光相比，C-22叶片中GS1蛋白的含量低12% - 37%，这与受粳稻染色体正向影响的QTL区域一致。在营养生长早期，C-22在温室中的分蘖比越光更活跃。在生殖阶段，C-22的穗数和总穗重均显著高于越光，尤其是在低氮条件下种植时。C-22的这些性状在稻田中得到了进一步证实。因此，在营养生长早期，Kasalath染色体对分蘖发育有正向影响，导致C-22在成熟阶段的穗数和穗重增加。这些数据表明，目标QTL（Pnn1；穗数1）在水稻分蘖和穗的发育中很重要。对穗数和第二腋芽发育分蘖形成比例（RDT）的连锁分析表明，Pnn1被定位在6.7厘摩的区域。
