不同浓度盐胁迫对甜椒生长及生理特性的影响

Effects of Salt Stress of Different Concentrations on Growth and Physiological Characteristics of Sweet Pepper

在温室条件下,以甜椒为试验材料,研究了不同浓度NaCl处理对甜椒生长、光合作用、叶绿素荧光、根系活力、抗氧化酶活性及渗透调节物质的影响。本研究结果表明,随着NaCl处理浓度的增加,甜椒株高、茎粗、植株地上部鲜重、净光合速率(Pn)、气孔导度(Gs)、胞间二氧化碳浓度(Ci)、蒸腾速率(Tr)、过氧化氢酶(CAT)活性、根系活力均逐渐降低,且植株须根逐渐减少;而超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、愈创木酚过氧化物酶(G-POD)活性、丙二醛(MDA)和脯氨酸含量逐步升高;甜椒叶片实际光化学量子产量(Yield)、光合电子传递速率(ETR)、光化学猝灭(qP)在高浓度200 mmol/L NaCl处理下显著降低,而非光化学猝灭(qN)却显著增加;叶绿素、类胡萝卜素和可溶性蛋白含量在50 mmol/L NaCl处理下显著增加,100~200mmol/L NaCl处理下明显降低。本研究初步认为,甜椒植株在50 mmol/L NaCl处理浓度下有较好的耐受性,植株可以通过调节抗氧化系统、增加渗透调节物质含量等来更好地适应盐胁迫;200 mmol/L NaCl处理可能导致甜椒出现不可逆的伤害。

Taking sweet pepper as material,the effects of different concentrations of NaCl treatments on sweet pepper growth,photosynthesis,chlorophyll fluorescence,root activity,antioxidant enzyme activities and osmotic regulators were studied in greenhouse.The results showed that plant height,stem diameter,fresh weight of aerial part,net photosynthetic rate(P_n),stomatal conductance(G_s),intercellular carbon dioxide concentration(C_i),transpiration rate(T_r),catalase(CAT)activity,root activity and the number of fibrous roots gradually decreased with the increase concentration of Na Cl treatments,while the superoxide dismutase(SOD),ascorbate peroxidase(APX),and guaiacol peroxidase(G-POD)activity,malondialdehyde(MDA)and proline content gradually increased as the increasing of NaCl concentration.The actual photochemical quantum yield,photosynthetic electron transport rate(ETR),photochemical quenching(qP)of sweet pepper leaves were significantly reduced in high concentration of 200 mmol/L Na Cl treatment,but non-photochemical quenching(qN)was significantly increased.Chlorophyll content,carotenoid content,and soluble protein content increased significantly in 50 mmol/L NaCl treatment and they clearly decreased under concentration of 100~200 mmol/L NaCl treatment.The present research preliminarily believes that sweet pepper plants have better tolerance in concentration of 50 mmol/L NaCl treatment and the plants could adjust the antioxidant system,and increase the content of osmotic regulators,etc.to better adapt to salt stress.200 mmol/L Na Cl treatment may cause irreversible damage to sweet peppers.