花期干旱胁迫对籼稻近等基因系育性的影响

Effects of Drought Stress on Fertility of Near-Isogenic Indica Rice Lines at Flowering Stage

以27份形态性状发生突变的标记基因材料杂交并多次回交所构建的近等基因系及其轮回亲本浙辐802(早籼稻)为材料,于水稻主穗见穗至此后15d进行干旱胁迫,研究花期干旱胁迫条件下各品系的育性与农艺性状和耐旱性生理性状的关系。试验结果表明,花期干旱胁迫使株高受抑,上3叶绿叶面积减少,稻株干物质量和结实率显著下降,材料的耐旱性与结实性无关。根据干旱胁迫指数将该近等基因系分为钝感(结实率下降<30%)、耐旱(结实率下降幅度在31%～50%)、不耐旱(结实率下降幅度在51%～80%)及敏感(结实率下降幅度>80%)4类,轮回亲本浙辐802为干旱敏感材料。具有卷叶、披叶等传统的耐旱性状的近等基因系未能表现出较强的耐旱性,而具有黄绿色叶与金黄色的谷色的近等基因系则有较高的耐旱性。

The relationships between spikelet fertility and agronomic traits or physiological characteristics related to drought resistance were analyzed with 27 near-isogenic lines and their recurrent parent Zhenfu 802（Oryza sativa L.subsp.indica） as materials under 15 d drought stress since flowering of main culm.The results presented that drought stress at the flowering stage not only decreased the plant height,leaf area and plant dry weight,but also significantly decreased the seed-setting rate.Drought resistance of the tested near-isogenic lines has no relationship with the seed-setting rate under well-watered conditions.According to the drought stress index（DSI）,the recurrent parent Zhefu 802 was classed as drought sensitive variety,and the 27 near-isogenic lines could be divided into drought resistant lines（DSI0.30）,semi-drought resistant lines（0.31DSI0.50）,semi-drought sensitive lines（0.50DSI0.80） and drought sensitive lines（DSI0.80）.Furthermore,the near-isogenic lines with classic drought resistant morphological traits,such as curl and droopy leaves,failed to show higher drought resistance,whereas those with yellowish green leaf or golden hull showed higher drought resistance.