Analysis on Chlorophyll Fluorescence Parameters of PhotosystemII in Cassava Diploid and its Autotetraploid

In order to study the chlorophyll fluorescence parameters difference between South China 205 and its tetraploid, modulated chlorophyll fluorescence imaging system Imaging-Pam was used to measure the chlorophyll fluorescence parameters. The results showed that: chlorophyll a, chlorophyll b and total chlorophyll in tetraploid were significantly increased, also the fluorescence parameters including Fo, ΦPSⅡ, q P and ETR, while NPQ was significantly decreased, Fv/Fmwas not significantly changed. Chlorophyll content and ΦPS Ⅱ, q P and ETR were increased significantly, indicating that light-harvesting ability and photochemical conversion rate in PSII reaction center of tetraploid leaves were higher than that of SC205 and the photosynthesis efficiency of the tetraploidy was improved.