齐穗后弱光胁迫对杂交籼稻节间非结构性碳水化合物积累转运的影响

Effects of shading stress after heading on the accumulation and remobilization characteristics of non-structural carbohydrates in internodes of indica hybrid rice

  • 摘要: 以杂交籼稻组合‘宜香优2115’和‘C两优华占’为试验材料, 采用大田遮光试验(遮光53%)研究了杂交籼稻不同节间非结构性碳水化合物(NSC)含量和积累量的动态变化以及转运特性。结果表明, 齐穗后下部节间NSC含量迅速下降, 其储藏的NSC即被转运利用, 而上部节间NSC转运相对迟缓, 且部分节间可出现NSC继续积累现象; 成熟期遮阴处理各节间NSC含量较对照显著下降20.98%~95.45%(P<0.05), NSC转运量显著增加3.37%~453.70%(P<0.05), 而NSC转运率和贡献率则分别提高3.25~325.07个百分点和0.63~9.18个百分点。除穗颈节外, ‘宜香优2115’各节间NSC含量和积累量以及节间转运量和贡献率均高于‘C两优华占’; 遮阴处理下‘宜香优2115’因其花前各节间较高的NSC积累量和花后较高的转运量, 使其结实率和产量下降幅度明显低于‘C两优华占’。相关分析表明, 对照与遮阴处理的产量差值与成熟期第3和第5节间NSC积累量差值呈显著负相关(P<0.05), 与转运量和转运率差值呈显著正相关关系(P<0.05)。可见, 水稻可通过增强花前各节间, 特别是第3和第5节间积累NSC的转运再利用, 来降低弱光胁迫对水稻产量的不利影响。因此, 生产上可通过选用花前节间NSC积累量高, 花后转运量大的品种来降低弱光胁迫对水稻的危害。

     

    Abstract: This study was performed to investigate the dynamic changes of non-structural carbohydrate (NSC) content and accumulation, as well as the redistribution characteristics of NSC in different internodes of hybrid Indica rice. A field experiment with 53% shading treatment was conducted using the Indica rice hybrids ‘Yixiangyou 2115’ and ‘C Liangyouhuazhan’. The results showed that the NSC content in the lower internodes rapidly decreased after heading, which resulted in faster remobilization of stored NSC in the lower internodes. Meanwhile, the remobilization of the stored NSC in the upper internodes was slower than that in the lower internodes. In addition, some of the upper internodes continued to accumulate NSC after heading. Compared with the control, the shading treatment significantly decreased the NSC content in each internode of by 20.98% to 95.45% at the maturity stage (P<0.05), and increased the remobilization amount of stored NSC in each internode by 3.37% to 453.70%, as well as the remobilization rate and contribution rate of remobilized stored NSC in each internode by 3.25 to 325.07 and 0.63 to 9.18 percentage points, respectively. With the exception of neck internodes, the content and accumulation of NSC, as well as the remobilization amount and contribution rate of stored NSC in each internode was greater in ‘Yixiangyou 2115’ than in ‘C Liangyouhuazhan’. Compared to ‘C Liangyouhuazhan’, ‘Yixiangyou 2115’ exhibited lower reduction of both seed-setting rate and grain yield under shading stress, which was attributed to the greater NSC accumulation before heading and remobilization amount of stored NSC after heading in each internode. Correlation analysis indicated that the difference in grain yield between the control and shading treatments was significantly negatively correlated with the difference in NSC accumulation in the third and fifth internodes, but significantly positively correlated with the differences in remobilization amount of stored NSC and the remobilization rate within these internodes. In conclusion, rice could reduce the adverse effects of shading stress on grain yield by enhancing the remobilization of stored NSC in internodes (especially the third and fifth internodes) after heading. Therefore, the selection of rice varieties with high NSC accumulation before heading and high NSC remobilization after heading is helpful in relieving the harm caused by shading stress.

     

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