Comparison of chlorophyll fluorescence Fv/Fm characteristics of four michelia trees
The diurnal changes of chlorophyll fluorescence parameter Fv/Fm of seedlings of Michelia maudiae, Michelia platypetala, Michelia foveolata and Michelia wilsonii in different seasons and correlations between FvlFm values and photosynthetically active radiation (PAR) , air temperature (Ta) and air humidity (RH) were studied in this paper. The diurnal change range of Fv/Fm of four michelia trees in spring was small and the values in a whole day were higher than 0.75. There was no significant correlation between the chlorophyll fluorescence parameter Fv/Fm of four michelia trees and PAR, Ta and RH in spring. The values of Fv/Fm in a wole day in summer showed a trend of descending first and then ascending and the lowest values (<0.75) appeared between 12:00 and 14:00. A negative relation was founded between Fv/Fm value of Michelia maudiae and Ta and RH, while a positive correlation between Fv/Fm value of Michelia platypetala and Ta and RH in summer; there was a significant negative correlation between Fv/Fm value of Michelia foveolata and PAR and Ta in summer. Based on the diurnal changes trend and the Fv/Fm value in a whole day, the effects of reversible stress on the photosynthetic tissues of Michelia maudiae, Michelia platypetala and Michelia foveolata were founded in summer from 12:00 to 14:00. The significant negative correlation and positive correlation between the values of Fv/Fm of Michelia wilsonii and Ta and RH were also founded in summer, respectively. The values of FvlFm of Michelia wilsonii in a whole day in summer were below 0.75, indicating that there was irreversible stress effect on the photosynthetic tissues of Michelia wilsonii in summer. The diurnal change of Fv/Fm of Michelia wilsonii in autumn presented a trend of descending first and then ascending, and the lowest value (0.72)was at 14:00, and there was a significant postive correlation between the value of Fv/Fm and RH. The diurnal changes of Fv/Fm of the other three michelia trees in autumn were small, and the values were higher than 0.75 in a whole day. Meanwhile, no significant correlation between the values of Fv/Fm of three michelia trees mentioned above, and PAR, Ta and RH were founded from experimental results in autumn. The diurnal changes of Fv/Fm of four michelia trees in winter were ascending at first and then descending, and significant postive correlation between the Fv/Fm and Ta was showed from the experimental results. The diurnal changes trend and the values of Fv/Fm in a whole day in winter indicated that the effects of stress on the photosynthetic tissues of four michelia trees were only reversible.
国家科技期刊平台
NSTL
万方数据
维普
