Photosynthetic features of leaf and silique of 'Qinyou 7' oilseed rape(Brassica napus L.) at reproductive growth stage

Photosynthetic products are mainly produced by leaf and green silique of oilseed rape(Brassica napus L.) at reproductive growth stage. This study aimed to compare photosynthetic features of leaf and green silique of 'Qinyou 7' hybrid oilseed rape variety. Results showed that, during photosynthetic day time, net photosynthetic rate(P_N) and stomatal conductance(gs) of leaf were markedly higher than that of silique. Compared with silique, leaf had significant higher P_N, g_s, light saturated net photosynthetic rate(P_(Nmax)), light saturation point(LSP), and apparent quantum yield(AQY), but lower light compensation point(LCP), CO_2 compensation point(Γ) and carboxylation efficiency(CE) under various light densities and CO_2 concentrations. Carboxylation activities of ribulose-1, 5-bisphosphate carboxylase/oxygenase(Rubisco), phosphoenolpyruvate carboxylase(PEPC) and chlorophyll a, b(Chl a, b) of leaf were significantly higher than that of silique shell. Our study demonstrated that leaf of oilseed rape at reproductive growth stage had higher photosynthetic capacity than green silique due to its higher carboxylation activity of photosynthetic enzymes as well as higher gs and Chl contents. This study might have good implication in selecting a biological control strategy to enhance seed yield and oil production of oilseed rape.

Photosynthetic products are mainly produced by leaf and green silique of oil-seed rape （Brassica napus L.） at reproductive growth stage. This study aimed to compare photosynthetic features of leaf and green silique of ‘Qinyou 7’ hybrid oilseed rape variety. Results showed that, during photosynthetic day time, net photosynthetic rate （PN） and sto-matal conductance （gs） of leaf were markedly higher than that of silique. Compared with silique, leaf had signifcant higher PN, gs, light saturated net photosynthetic rate （PNmax）, light saturation point （LSP）, and apparent quantum yield （AQY）, but lower light compensa-tion point （LCP）, CO2 compensation point （Γ） and carboxylation effciency （CE） under var-ious light densities and CO2 concentrations. Carboxylation activities of ribulose-1, 5-bis-phosphate carboxylase/oxygenase （Rubisco）, phosphoenolpyruvate carboxylase （PEPC） and chlorophyll a, b （Chl a, b） of leaf were signifcantly higher than that of silique shell. Our study demonstrated that leaf of oilseed rape at reproductive growth stage had higher photosynthetic capacity than green silique due to its higher carboxylation activity of pho-tosynthetic enzymes as well as higher gs and Chl contents. This study might have good implication in selecting a biological control strategy to enhance seed yield and oil produc-tion of oilseed rape.