小偃54和8602及其杂交后代小偃41和小偃81花后旗叶光合特性比较

通过测定叶绿体色素含量、叶片气体交换参数、叶绿素荧光及820 nm吸收参数，比较了小偃54 (XY54)和8602及其杂交后代小偃41 (XY41)和小偃81 (XY81)花后旗叶光合特性的差异。在开花期，4个品种(系)的叶绿素和类胡萝卜素的含量不同，基本表现为杂交后代高于双亲，且以XY81最高；8602品系的光合速率(P_n)和羧化效率(CE)最高，XY41品系的气孔导度(G_s)最低，而XY54品种的CE最低。4个小麦品种(系)的胞间CO₂浓度(C_i)、K点可变荧光(F_K)占F_J–F_O荧光振幅的比率(W_k)、光系统II(PSII)最大量子效率(F_v/F_m)、电子传递到Q_A下游的概率(Ψ_o)、电子从系统间电子传递体传递给光系统I(PSI)受体侧电子受体的概率(δ_Ro)、820 nm相对可变透射光(ΔI/I_o)、PSII的实际光化学效率(Φ_PSII)和非光化学猝灭(NPQ)无显著差异。小麦开花后，XY54的叶绿素含量、P_n、G_s、CE、F_v/F_m、δ_Ro及ΔI/I_o的下降幅度和W_k的上升幅度显著大于其他3个品系，但C_i、Ψ_o、Φ_PSII和NPQ与其他3个品系没有显著差异。8602和2个杂交后代的上述参数的变化趋势在整个发育期内基本相同。以上结果表明，与XY54相比，XY41和XY81的光合下降幅度较小，可能与它们的光合暗反应能力不同有关，而不是三者的叶绿素含量、气孔导度及光反应的能力不同所造成，杂交后代XY81和XY41可能遗传了8602品系较高的光合暗反应特性。

Photosynthetic Characteristics after Anthesis in Flag Leaves of Wheat Cultivars Xiaoyan 54 and 8602 and Their Hybrids Xiaoyan 41 and Xiaoyan 81

Wheat lines Xiaoyan 41 (XY41) and Xiaoyan 81 (XY81) are hybrid progenies of Xiaoyan 54 (XY54) and 8602, which show distinct differences from their parents in photosynthesis characteristics. In this study, the gas exchange, chlorophyll fluorescence, and 820 nm transmission in flag leaves after anthesis were compared between hybrids XY41 and XY81 and parents XY54 and 8602. At anthesis, contents of chlorophyll a, chlorophyll b, and carotenoids were higher in the hybrids than in the parents, especially in XY81....