Increasing photosynthesis and biomass of poplars with Burkholderia multivorans WS-FJ9.

To study the growth-omoting mechanisms of Burkholderia multivorans WS-J9 on poplars, photosynthetic indexes ［net photosynthetic rate （Pn）, transpiration rate （Tr），stomatal conductance （Gs）, and intercellular CO2 concentration （Ci）］ and fluorescence parameters ［Fv /Fm, PS II, total chlorophyll （TChl）, and Chla/Chlb］ of NL-95 poplar （Populuseurmericana NL-95）leaves inoculated with a strain of WS-J9 were determined by a portable photosynthetic apparatus （LI-400XT）. Simultaneously, chlorophyll content of poplar leaves, seedling height, ground diameter, and biomass were measured. Results showed that during the treatment period （150 days）, Pn, Tr and Gs all increased earlier and decreased later with Pn and Tr higher, and Ci lower than control groups （P＜0.05）. At the 30th day, Gs was lower and after the 60th day higher than the control groups （P＜0.05）; whereas Ci was reversed. The fluorescence parameters Fv/Fm, PSII, TChl, and Chla/Chlb were higher than the control groups （P＜0.05）. At the 150th day, seedling height, ground diameter, and biomass were also greater than the control groups （P＜0.05）. This study illustrated the growth-romoting mechanisms of strain WS-J9 on NL-95 poplar from the perspective of photosynthesis and biomass, provided a reference basis for development and utilization of bio-acterial manure, and could be of great importance in popularizing sustainable agriculture. ［Ch, 4 fig. 1 tab. 21 ref.］