一个新的水稻脆秆突变体bc17的鉴定及基因定位

利用重离子辐照武运粳7号(Wuyunjing 7,wyj7)获得一个脆秆突变体bc17(brittle culm 17),该突变体脆性特征仅在茎秆中表现,叶片正常,并且茎秆脆性在抽穗后开始表现,随着成熟度的增加脆性特征逐渐显著。农艺性状分析表明,该突变体生长发育受到影响,株高显著低于野生型,分蘖数减少以及结实率降低。茎秆和叶片生化成分测定显示,与野生型相比,bc17茎秆和叶片的纤维素含量分别降低22.70%和18.67%,半纤维素含量分别升高45.76%和31.36%。bc17茎秆的抗折力、拉伸力均显著低于野生型,表明茎秆的机械强度发生改变。组织解剖学观察发现,bc17茎秆的厚壁细胞孔隙变大,结构疏松,细胞数目减少。遗传分析表明,bc17的脆秆特征受单隐性核基因控制。利用图位克隆技术将bc17基因精细定位于水稻第7号染色体162 kb区域中,生物信息学分析表明可能是一个新的水稻脆秆基因,为揭示水稻细胞壁合成分子机制的研究提供重要的材料支撑。

Identification and gene localization of a novel rice brittle culm mutant bc17

A brim culm mutant bc17(brittle culm 17)was obtained by irradiating wyj7(Wuyunjing 7)with heavy ions.The brittle traits of the mutant were only found in the stalks and not in the leaves.The brittleness of the culm began to appear after heading stage,while it became more obvious as rice grew from heading stage to maturity stage.The growth and development of the mutant were affected,the plant height of the mutant was significantly lower than that in the wild type,and tiller number and seed setting rate were also lower than in the wild type.Compared with wild type,the cellulose content in bc17 culms and leaves decreased by 22.7%and 18.67%,while the hemicellulose content increased by 45.76%and 31.36%,respectively.The breaking resistance and tensile force of bc17 were significantly lower than those of wild type,indicating that the mechanical strength of the culm changed.The thick-walled cells of bc17 culms had larger pores,looser structures,and fewer cells.The fragile characteristics of bc17 were controlled by a single recessive nuclear gene.The bc17 gene was located in the 162 kb region of chromosome 7 by map-based cloning.Bioinformatics analysis indicated that it might be a novel gene related to rice brittle culm.These findings provided an important material support for the research on the molecular mechanism of cell wall synthesis in rice.