作 者：
赵娜;秦都林;聂军军;郭文君;祁杰;刘艳慧;毛丽丽;宋宪亮;孙学振
单 位：
山东省棉花生产技术指导站;曲阜市农业局;山东农业大学农学院/作物生物学国家重点实验室
摘 要：
【目的】通过对不同抗虫棉品种功能叶叶片PSⅡ性能和有关参数的研究,探讨钾影响棉花叶片光合系统的机理,以期为棉花的钾肥施用提供科学依据。【方法】选用三种抗虫棉岱字棉99B (DP99B)、鲁棉研21(L21)、冀棉169 (J169)为供试材料。设2个施钾水平:施硫酸钾240 kg/hm~2 (K)和不施钾(CK)。于棉花见蕾期,利用便携式LI-6400XT光合仪测定了净光合速率(P_n)、气孔导度(G_s)、胞间CO_2浓度(C_i)。利用M-PEA型植物效率仪快速测定了叶绿素荧光动力学曲线(OJIP曲线)相关参数, PSⅡ反应中心单位活化截面积还原QA的激发能(TR_o/CS_m)、活性反应中心数目(RC/CS_m)、反应中心捕获的激子将电子传递到电子传递链中QA下游的其他电子受体的比例(Ψ_o)以及PSⅡ性能指数(PI_(abs)),PSⅡ单位反应中心热耗散掉的能量(DI_o/RC)、K点的可变荧光F_k占振幅F_j-F_o的比例(W_k)以及J点的相对可变荧光(V_j)。利用JIP-test进行了叶绿素荧光动力学曲线(OJIP曲线)的参数分析。【结果】施钾对三个棉花品种叶片的P_n、G_s、叶绿素含量、PSⅡ反应中心单位TRo/CS_m、RC/CS_m、Ψ_o以及PI_(abs)均有显著的提高作用,同时显著降低了PSⅡ的DI_o/RC、K点的W_k以及J点的V_j。施钾后,岱字棉99B (DP99B)、鲁棉研21 (L21)、冀棉169 (J169)的Pn在2016年分别提高了9.60%、19.84%、11.85%,2017年分别提高了9.14%、18.48%、9.60%;PSⅡ的整体性能(PI_(abs))分别增加了10.79%、17.93%、14.04%。【结论】施用钾肥有利于提高不同棉花品种叶片PSⅡ反应中心电子供体侧和受体侧以及PSⅡ反应中心电子受体侧之后的电子传递链性能,从而有效提高PSⅡ的整体性能,最终增强了叶片的光合能力。三个品种相比,施钾对L21光合系统的整体改善效果优于DP99B和J169。由此可见,在实际生产中,可以根据不同棉花品种对钾的敏感性合理施钾。但由于我国棉区较多,生产条件差异大,这一结论需在不同的种植区进行进一步验证。
译 名：
Effects of potassium application on performance of photosystem Ⅱ of various Bt cotton genotypes
作 者：
ZHAO Na;QIN Du-lin;NIE Jun-jun;GUO Wen-jun;QI Jie;LIU Yan-hui;MAO Li-li;SONG Xian-liang;SUN Xue-zhen;College of Agronomy, Shandong Agricultural University/State Laboratory of Crop Biology;Shandong Province Cotton Production Technical Guidance Station;Qufu Agricultural Bureau;
单 位：
ZHAO Na%QIN Du-lin%NIE Jun-jun%GUO Wen-jun%QI Jie%LIU Yan-hui%MAO Li-li%SONG Xian-liang%SUN Xue-zhen%College of Agronomy, Shandong Agricultural University/State Laboratory of Crop Biology%Shandong Province Cotton Production Technical Guidance Station%Qufu Agricultural Bureau
关键词：
Bt cotton;;potassium fertilizer;;photosynthetic system;;photosystem Ⅱ performance
摘 要：
【Objectives】The paper studied the fluorescence dynamics of functional leaves of Bt cotton genotypes under the condition of potash fertilization, to provide a scientific basis for K fertilizer application in Bt cottons.【Methods】Field experiments were carried out at Shandong Agricultural University Experimental Station during 2016-2017. Three cotton genotypes, DP99 B, L21 and J169 were chosen, and two treatments of no K fertilization(CK) and application of K_2SO_4 240 kg/hm~2(K) were used in the experiments. Samples of functional leaves were collected during the budding stage of cotton. The net photosynthetic rate(Pn), stomatal conductance(Gs) and chlorophyll content were measured using LI-6400 XT potable photosynthesis system. The chlorophyll fluorescence transients were measured using multiple plant efficiency meter(M-PEA Hansatech), including the excitation energy of light absorbed by excited cross section of PSII reaction center(TR_o/CS_m), the number of active reaction centers(RC/CS_m), probability of an electron moving from QA to QB(Ψo) and the performance index of absorption basis(PI_(abs)). The related parameters of the dynamics of the photosystemⅡperformance(OJIP) were analyzed using JIP-test.【Results】The basal application of K fertilizer significantly increased net photosynthetic rate(P_n), stomatal conductance(G_s), chlorophyll content, excitation energy of light absorbed by leaf area per PSII reaction center(TR_o/CS_m), number of active reaction centers(RC/CS_m), probability of an electron moving from QA to QB(Ψ_o), performance index of absorption basis(PI_(abs)). At the same time, application of K fertilizer significantly reduced the heat dissipation energy per unit reaction center(DI_o/RC), the ratio of a variable fluorescence F_k to the amplitude F_o-F_j(W_k) and the ratio of a variable fluorescence F_j to the amplitude Fo-Fp(V_j). After potassium fertilization, the net photosynthetic rate(P_n) was increased significantly by 9.60%, 19.84%, 11.85% in 2016 and by 9.14%, 18.48%, 9.60% in 2017, and the performance index(P_(Iabs)) was also increased significantly by 10.79%,17.93% and 14.04% for Bt cotton genotype DP99B, L21 and J169, respectively.【Conclusions】Potassium fertilizer application is beneficial to improve the performances of electron donor and acceptor in PSⅡ reaction center of various Bt cotton genotypes, and the performance of the electron transfer chain at the electron acceptor side of the PSII reaction center was also improved. Thus, potassium fertilizer application could effectively improve the overall performance of PSⅡ and ultimately enhanced the photosynthetic capacity of different cotton genotypes. L21 showed better responsive effect to potassium fertilization than DP99 B and J169. Thus, rational potassium fertilization in actual cotton production should consider the sensitivity of different genotypes to potassium fertilization.
