植物生长调节剂对油菜生长及冻害后光合作用和产量的调控效应

Regulation Effects of Exogenous Hormones on Growth and Photosynthesis and Yield of Rapeseed (Brassica napus L.) after Frozen

在油菜始花期喷施不同浓度的脱落酸(ABA)和油菜素内酯(BR),分析其对油菜叶片光合速率和产量的影响;2008年1月低温冰冻天气之后,采用优化浓度的ABA和BR处理,测定油菜叶片的气体交换参数和叶绿素荧光参数,比较角果形态变化规律及产量构成因素。主要结果如下:与对照(CK)相比,喷施76×10?6molL?1ABA和1×10?6molL?1BR能延缓叶片光合速率的下降,冻害后喷施该浓度ABA和BR提高了叶片净光合速率(Pn)、光饱和点(LSP)、气孔导度(Gs)、胞间CO2浓度(Ci)与蒸腾速率(Tr);最大光化学效率(Fv/Fm)、光系统II量子产量(ΦPSII)与光化学猝灭系数(qP)均升高,叶绿素初始荧光(Fo)和非光化学猝灭系数(NPQ)降低,ABA和BR处理还提高叶片中叶绿素含量及可溶性蛋白的含量;角果面积增大,BR处理后单株角果数、每角粒数、千粒重及产量都比对照增加,ABA处理可增加角粒数和千粒重,进而提高油菜的产量。总之,76×10?6molL?1ABA和1×10?6molL?1BR能促进油菜生长并有效缓解冻害对油菜的影响。

Different concentrations of exogenous hormones were applied on rapeseed at the initial blossoming stage. The net photosynthetic rate （Pn） and yield were investigated. In January 2008, a heavy snow and low temperature for a period destroyed crops including winter rape. In this experiments, exogenous hormones ABA and BR with optimal concentrations were applied on the rapeseed （Brassica napus L.） plants after the frozen from the worst weather. The gas exchange parameters and chlorophyll fluorescence characteristics of leaves as well as the regularity of pod size changes and yield components were determined. The results were as follows： ABA （76×10^-6 mol L^-1）and BR（1×10^-6 mol L^-1） could delay the decreasing of net photosynthetic rate （Pn） in short petiole leaves. The Pn, stomatal conductance （Gs）, intercellular CO2 concentration （Ci）, transpiration rate （Tr） and photosynthetic saturated light intensity （LSP） were increased after exogenous hormones treatment. ABA and BR treatments also caused a significant increase in the maximum photochemical efficiency of photosystem Ⅱ （Fv/Fm）, the quantum yield of electron transport （ΦPSⅡ）, the photochemical quenching co-efficient （qP）, Chl content and soluble protein content. These changes were accompanied by the decline in both minimal fluorescence （Fo） and non-photochemical quenching co-efficient （NPQ）. The pod surface areas per pod were increased. The number of the first branches per plant and seeds per pod and 1000-seed weight were raised, resulting in improvement of yield after BR treatment. As to the plants after ABA treatment, the high yield was mainly attributed to the increasing of seeds per pod and 1000-seed weight. In conclusion, ABA （76×10^-6 mol L^-1） and BR （1×10^-6 mol L^-1） treatments are effective on promoting the growth and relieving the negative effects of frozen on rapeseed.