Effect of no donor SNP on photosynthetic pigments and chlorophyll fluorescence under enhanced UV-B radiation in larix gmelinii

The experiment was designed with control (CK) groups under natural light, UV-B treatment (T
0
) group, and UV-B & SNP combined treatment (T
1
, T
2
, T
3
, T
4
). Each treatment was determined photosynthetic pigments(chl a, chl b and car) and chlorophyll fluorescence parameters respectively. The results of variance analysis showed 0.5 mM sodium nitroprusside (SNP), a NO donor, have significant impact on nursery stocks of larix gmelinii under enhanced UV-B radiation stress. 0.5 mM SNP can significantly inhibited the apparent decline in photosynthetic pigments, Fv/Fm, Φ PSII, Fv'/Fm' and qP, and the obvious increase in chl a /chl b, F
0
and NPQ after supplement UV-B radiation. The aim of this study was to investigate an active role of exogenous nitric oxide in photosynthetic protection of larix gmelinii's nursery stocks under enhanced UV-B radiation.