Effects of homologous genome 7 on gas exchange and chlorophyll fluorescence parameters of wheat

[Objective] To study the effects of homologous chromosomes 7（7A，7B and 7D）on wheat photosynthesis and provide theoretical basis for breeding high photosynthetic efficiency wheat by genetic，physiological and biochemical means. [Method] The Triticum asetivum cultivar Chinese Spring wheat and nullisomic wheat （N7A，N7B and N7D）were planted in greenhouse. The photosynthetic indexes were determined at early filling stage. [Result] The photosynthetic rate (Pn), stomatal conductance (Gs), primary photochemical efficiency (Fv/Fm), actual chemical efficiency of photosystem II (ФPS II) and apparent electron transfer rate of photosystem II (ETR) were significantly lower in the N7A and N7B than in the Chinese Spring (P 0.05). The photosynthetic rate and stomatal conductance was significantly lower in the N7D than in the Chinese Spring (P 0.05). The Fv/Fm, ФPS II, ETR of N7D were higher than that of the Chinese Spring without significant difference. [Conclusion] The homologous chromosomes 7A and 7B have positive effects on