97-7未能发挥超高产潜力光合原因的研究

以武育粳 3号 (广种高产中粳品种 )和 97- 7(具有超高产潜力的中粳选系 )为材料比较了两个品种剑叶光合功能衰退过程 ,初步找出 97- 7没有发挥超高产潜力的原因 .结果表明 ,尽管 97- 7剑叶的叶绿素含量 (全展时 SPAD值为 5 9.4)比武育粳 3号剑叶叶绿素含量 (全展时 SPAD值为 42 .6 )高出很多 ,但对提高光合速率没有发挥作用 .光合功能衰退过程中 ,97- 7剑叶叶绿素含量下降比武育粳 3号快 ,其剑叶叶绿素含量的相对稳定期 (RSP)比后者短 7d,前者为 37d,后者为 44 d.97- 7剑叶的光合速率下降和 Ru BPCase活性下降也都快于武育粳 3号的剑叶 .这些方面导致了 97- 7剑叶单位叶面积的叶源量略小于武育粳 3号 ,使它没能发挥超高产潜力 .

Study on the Photosynthetic Reasons for Inability of 97-7 to Exert Its Superhigh Yield Potential

Wuyujing 3 (wildly-cultivated, high yield median sinica) and 97-7 (potentially superhigh yield median sinica) are used to compare the difference in photosynthetic function declination. Some photosynthetic reasons for inability of 97-7 to exert its superhigh yield potential have been found. The results show that apparently higher chlorophyll content in 97-7 flag leaves (when fully expanded, SPAD was 59.5 for 97-7, and 42.6 for Wuyujing 3) does not make any contribution to increase in photosynthetic rate. During photosynthetic declination, compared with Wuyujing 3 flag leaves, the chlorophyll content in 97-7 flag leaves decreases faster, and its RSP (relative stable phase) of chlorophyll content is seven days shorter than that of Wuyujing 3 too, 37 days for the former and 44 days for the latter. The drops in photosynthetic rate and in activity of RuBPCase in 97-7 flag leaves are faster than those in Wuyujing 3 flag leaves, respectively. These make the LSC (leaf source capacity) of 97-7 flag leaves slightly smaller than that of Wuyujing 3 and make 97-7unable to exert its superhigh yied potential.