Abstract:
The photosynthetic fluorescence characteristics of 8
Zanthoxylum bungeanum varieties in the Loess Plateau region of central Gansu were explored to provide reference for the excellent cultivar screening and adaptability research of
Zanthoxylum bungeanum in the Loess Plateau region of central Gansu. By taking the 2-year-old seedlings of 8
Zanthoxylum bungeanum varieties as the research object, the photosynthetic parameters such as the net photosynthetic rate and stomatal conductivity of
Zanthoxylum bungeanum were measured by using the photosynthetic analyzer, and the chlorophyll fluorescence characteristics such as the initial fluorescence and photochemical quenching coefficient were measured by using the luminoscope. Then, the photosynthetic characteristics and chlorophyll fluorescence parameters of leaves among different
Zanthoxylum bungeanum varieties were compared and analyzed. The results showed that: the photosynthetic characteristics were presented as the net photosynthetic rate (
Pn ) and transpiration rate (
Tr ) of different
Zanthoxylum bungeanum varieties decreased gradually with time. The
Gs of Qin’an Dahongpao and Wucimei
Zanthoxylum bungeanum decreased gradually with time. Nanqiang No.1, Goujiao and Shizitou showed a trend of increasing first and then decreasing, while other varieties had no obvious variation tendency. The
Pn, stomatal conductivity (
Gs ) and transpiration rate (
Tr ) of Wucimei
Zanthoxylum bungeanum were the highest in July. Except that the intercellular CO
2 concentration (
Ci ) of Huanggai and Goujiao decreased first and then increased, the intercellular CO
2 concentration (
Ci ) of other
Zanthoxylum bungeanum varieties showed a gradual rising tendency. The fluorescence characteristics showed that except for the
F0 of Qin’an Dahongpao and Goujiao increased first and then decreased with time, the initial fluorescence (
F0) of other varieties decreased gradually with time. The maximum fluorescence (
Fm) of Qin’an Dahongpao and Qin’an No.1 in different periods was significantly higher than that of other varieties. The maximum primary photochemical quantum efficiency (
Fv/
Fm) of PSⅡ in each
Zanthoxylum bungeanum variety did not change significantly during the whole growth period, which was basically maintained at 0.6-0.8. In September, the photochemical pathway transformation energy (ψPSⅡ) and electron transporting rate (
ETR) of Wucimei
Zanthoxylum bungeanum were significantly higher than those of other varieties. The photochemical quenching coefficient (
qP) of each
Zanthoxylum bungeanum variety showed different trends with time, but there was no significant change in the whole growth period of Qin’an Dahongpao.