外源硫化氢对盐胁迫下加工番茄幼苗光合参数及叶绿素荧光特性的影响

为探究外源硫化氢(H_2S)对盐胁迫下加工番茄幼苗光合作用和光合荧光参数的影响,以耐盐性不同的2个加工番茄KT-7(耐盐性强)和KT-32(耐盐性弱)为材料,采用分光光度法、CIRAS-3型光合仪和Imaging-PAM调制荧光成像系统分别测定光合色素含量、光合参数和叶绿素荧光参数。结果表明,外源H_2S提高了盐胁迫下加工番茄幼苗的生长及叶绿素a、叶绿素b、胡萝卜素含量、净光合速率(P_n)、气孔导度(G_s)、叶片蒸腾速率(Tr)、PSⅡ最大光化学效率(F_v/F_m)和PSⅡ实际光化学效率(ΦPSⅡ);降低了胞间CO_2浓度(Ci)、PSⅡ调节性能量耗散的量子产额[Y(NPQ)]和非光化学猝灭系数(NPQ);而PSⅡ非调节性能量耗散的量子产额[Y(NO)]稳定在较低水平。此外,外源H_2S对KT-32的缓解效应强于KT-7。综上所述,外源H_2S通过提高加工番茄幼苗叶片的光合色素量和光合电子传递效率,有效地缓解盐胁迫对加工番茄叶片PSⅡ的伤害。本研究结果为探究外源H_2S增强加工番茄耐盐性研究提供了科学依据。

Effect of Exogenous Hydrogen Sulfide on Photosynthesis Parameters and Chlorophyll Fluorescence Characteristics of Processing Tomato (Lycopersicon esculentum Mill ssp.subspontaneum Brezh) Seedlings Under NaCl Stress

To explore effects of exogenous hydrogen sulfide on seedling photosynthesis and photosynthetic fluorescence characteristics in the leaves of processing tomato under salt stress,two processing tomato cultivars KT-7 (strong salt tolerance) and KT-32 (salt-sensitive) with different salt tolerances were selected as experiment materials by using.Spectrophotometry,CIRAS-3 type of photosynthetic apparatus and Imaging-PAM modulation fluorescence Imaging system to determine the photosynthetic pigment content,photosynthesis parameters and chlorophyll fluorescence parameters.The results showed that,exogenous hydrogen sulfide improved the growth and chlorophyll a,b,carotenoids contents,net photosynthetic rate (Pn),stomatal conductance (Gs),transpiration rate (Tr),maximal PS Ⅱ quantum yield (Fv/Fm) and PS Ⅱ actual photochemical efficiency (ΦPS Ⅱ) of processing tomato seedlings,but the level of concentration of CO2 (Ci),parameters of quantum yield of regulated energy dissipation [Y (NPQ)] and non photochemical quenching coefficient (NPQ) were decreased.Quantum yield of non-regulated energy dissipation [Y (NO)] kept at a lower level.The mitigation effect of hydrogen sulfide on KT-32 is stronger than KT-7.It is concluded that exogenous hydrogen sulfide could increase photosynthetic pigment content and improve photochemical electron transport efficiency and efficiently protect processing tomato leaves from PS Ⅱ damage.This study provides a scientific basis for exogenous hydrogen sulfide enhancement processing tomato salt resistance.