大白菜随体染色体的附加和减少对种株光合特性的影响

 以大白菜随体单体、三体和二倍体为试材，在自然条件下，对生殖生长期的功能叶的叶绿素含量、希尔反应活性、净光合速率、光合速率日变化、Rubisco活性等生理生化指标进行了测定，以研究同源染色体的附加和减少对光合特性的影响，为开展染色体工程育种提供参考。结果表明：随体染色体的减少或附加对叶绿素含量有正效应，对叶绿素a/b的比值有负效应。随体染色体的减少或附加对大白菜的光合速率都产生不同程度的负效应。随体三体和二倍体净光合速率日变化均呈典型的双峰曲线，有明显的“午休”现象，随体单体“午休”现象不明显。随体染色体的减少或附加对希尔反应和Rubisco活性均有负效应。希尔反应活性和Rubisco活性的降低是引起随体单体、三体光合速率降低的直接原因。

Characteristics of Photosynthesis in Seed Plants of Satellite Chromosome Monosome, Diploid and Trisome of Chinese Cabbage

In order to research the effect of additioning or dropping of satellite chromosome on the photosynthetic characteristics of Chinese cabbage, the satellite chromosome monosome(sat monosome), diploid and trisome(sat trisome) of Chinese cabbage were used to examine the chlorophyll content,Hill reaction activity, photosynthetic rate(Pn),diurnal variation and Rubisco activity etc.The result showed that the additioning or dropping of sat chromosome had a positive effect on chlorophyll content and a negative effect on chl.a/b. The additioning or dropping of sat chromosome had a negtive effect on the photosynthetic rate(Pn). The curves of diurnal change of Pn of trisome and diploid were similar, all showed typical two peaks and showed conspicuous ‘noon sleep’. The decline of Hill reaction activity and Rubisco activity were the direct factors resulting in low photosynthetic rate of sat monosome and sat trisome. The results helped to realize the function of sat chromosome of Chinese cabbage and high photosynthetic efficiency breeding using the chromosome engineering.