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以续随子为材料采用温室盆栽法,研究了14 d NaCl胁迫处理对其幼苗生长、光合作用和叶绿素荧光特性的影响。结果表明:①续随子幼苗的鲜重和干重在25 mmol.L-1NaCl胁迫时与对照无显著差异,但其随着NaCl浓度的继续增加均显著降低。②NaCl胁迫下,续随子幼苗叶片净光合速率(Pn)降低,胞间二氧化碳(Ci)浓度增大;随着NaCl浓度增加,Pn和Ci较对照的变化幅度增加。③NaCl胁迫下,续随子幼苗叶片的初始荧光(Fo)、最大荧光(Fm)、可变荧光(Fv)、恒态荧光(Fs)、恒态荧光与初始荧光差值(△Fo)、PSⅡ实际光化学效率(ФPSⅡ)及幼苗叶片光化学荧光猝灭系数(qP)均降低;在0～25 mmol.L-1NaCl胁迫下,幼苗叶片各荧光参数比对照略有下降。可见,NaCl胁迫下,续随子产生了光合作用的光抑制伤害。低浓度下,植株能够较多地将光能用于光化学反应,光抑制程度较低,保持了较高的净光合速率,最终明显减轻盐胁迫对植株生长的影响。
Using the continuous cotyledons as the material, the effects of NaCl stress on the growth, photosynthesis and chlorophyll fluorescence characteristics of seedlings under 14 d stress were studied. The results showed that: (1) The fresh weight and dry weight of cacao seedlings had no significant difference with the control under 25 mmol.L-1NaCl stress, but decreased with the increase of NaCl concentration. ② Under NaCl stress, the net photosynthetic rate (Pn) and intercellular carbon dioxide (Ci) concentration in leaves of cacti seedlings increased. With the increase of NaCl concentration, the change range of Pn and Ci increased compared with the control. Under the NaCl stress, the initial fluorescence (Fo), the maximum fluorescence (Fm), the variable fluorescence (Fv), the steady state fluorescence (Fs), the steady state fluorescence and the initial fluorescence difference (△ Fo) The actual photochemical efficiency (ФPSⅡ) and the photochemical quenching coefficient (qP) of seedling leaves decreased. Under the 0-25 mmol.L-1 NaCl stress, the fluorescence parameters of seedling leaves decreased slightly compared with the control. Can be seen, under NaCl stress, continued with the production of photosynthesis photoinhibition damage. Under low concentration, the plant can use more light for photochemical reaction, lower light inhibition, maintain a higher net photosynthetic rate, and ultimately significantly reduce the salt stress on plant growth.