【摘要】 供试化杀型(CHA)、T型三系杂种小麦及各自亲本在旗叶一生中的净光合速率(P_n)、叶绿素含量(Chl)和可溶蛋白含量(Sp)均在全展时达到最大值,以后逐渐下降.在春季生育期中群体光合速率(CAP)的变化趋势呈单峰曲线,于开花期达到最大值.与亲本和对照相比,杂种小麦在生育期间于上述性状上多表现正向优势,且优势随生育进程不断增大.杂种小麦在旗叶叶绿素含量缓降期(RSP)、光合速率高值持续期(PAD)和叶源量(LSC)上的表现也优于亲本.LSC与RSP和PAD呈显著正相关.在群体水平上,杂种和亲本、对照品种单位叶面积的光合速率值(CAP/LAI)相近,表明杂种在CAP上的优势主要起因于其LAI的增大.杂种小麦较亲本具有较高的叶绿素可变荧光/最大荧光(FV/FM)比值,这可能是其开花期间午间CAP衰减值低及表现较明显光合优势的原因之一.进一步改善杂种小麦的光合性能,增加光合产物向收获器官的转运效率,对于椎动杂种小麦在生产中的早日应用可能具有重要作用.更多还原

【Abstract】 During flag leaf growth span, the photosynthetic rate(Pn), chlorophyll content(Chl) and soluble protein content(Sp) of flag leaf all reached the highest values at the leaf full expansion for tested hybrid wheats and their parents, then gradually declined. During spring growth stage, the canopy photosynthetic rate (CAP) showed a curvilinear change with one peak, and reached the highest value at flowering stage. Compared with parents and contrast cultivar(CK), above photosynthetic traits nearly all showed positive heterosis in hybrid wheats during growth stage, and the heterosis increased along with the growth process. The relative steady phase of chlorophyll content (RSP), photosynthetic active duration (PAD) and leaf source capacity (LSC) of flag leaf in hybrid wheats were higher than those in parents and CK. There were significantpositive correlations between LSC and RSP, PAD. At population level, the values of photosyn-thetic rate per area(CAP/LAI) were similar among tested hybrid wheats, parents and CK. It is suggested that the heterosis of CAP in hybrid wheats mainly result from the increase of their LAI. Compared with parents and CK, hybrid wheats had higher ratio of chlorophyll variation fluorescence to maximam fluorescence (FV/FM), which probably is one reason that the decrease of CAP from 12:00 to 14:00 at flowering stage was low and the photosynthetic heterosis was evident in hybrid wheats. It will probably be important in increasing the yield heterosis of hybrid wheats by improving their photosynthetic capacities and increascing their transporting effeciency of photosynthetic product to harvest organ.更多还原