水稻显性半矮秆基因对株高表达的影响及其对GA_3的敏感性

Expression of Plant Height and Sensitivity to GA_3 of Dominant Semi-Dwarfing Gene in Rice

对具有显性半矮秆基因的6对高矮秆近等基因系的株高表达特性进行了比较。水稻显性半矮秆基因抑制了茎秆节间的伸长，矮秆系倒4～5、3、2、1节及穗长分别为高秆系的97．2％、53．3％、65．1％、61．9％和94．7％。通过对Y98149（突变体）和Y98148（野生型）在苗期和成株期对GA3反应的研究，发现Y98149较Y98148对外源赤霉素更敏感；内源赤霉素测定结果显示显性半矮秆突变体内源赤霉素含量较低，是野生型的78％。

Six tall and dwarf near isogenic lines derived from a dominant semi-dwarfing mutant were studied in plant height traits and sensitivity to GA3. The internode elongation was inhibited by the dominant semi-dwarfing gene. The lengths from the basal internode to the uppermost internode and the panicle length in dwarf near isogenic lines were 97. 2%, 53. 3%, 65.1%,61.9% and 94.7% of those in the tall ones, respectively. Compared with wild type Y98148, dwarf mutant Y98149 was much more sensitive to GA3 at both the seedling and adult stages, and showed lower endogenic GA3 content in plant, with about 78% of the wild one.