等渗盐胁迫对青椒实生苗与嫁接苗生长及生理特性的影响

Effects of Iso-osmotic Salt Stress on Growth and Physiological Characteristics of Green Pepper Seedlings and Grafted Seedlings

盐胁迫是抑制作物生长发育的非生物胁迫之一。本试验以青椒材料‘仕砧’和‘红缨枪’为砧木、‘奥黛丽’为接穗进行嫁接,探讨150 mmol/L NaCl与100 mmol/L Ca(NO_(2));等渗胁迫对青椒实生苗与嫁接苗生长、活性氧代谢及抗氧化酶活性的影响,以期为利用青椒嫁接栽培技术克服土壤盐渍化和连作障碍提供理论依据。结果表明,NaCl和Ca(NO_(2));胁迫显著抑制了青椒幼苗生物量的积累,增加了根系的O_(2)^(-)、H_(2)O_(2)和MDA含量,降低了抗氧化酶活性,但嫁接苗受NaCl和Ca(NO_(2));胁迫的抑制程度显著小于实生苗,且Ca(NO_(2));胁迫的抑制效果更显著;嫁接苗根系抗氧化酶(SOD、POD和CAT)活性显著高于实生苗,根系O_(2)^(-)、H_(2)O_(2)和MDA含量显著低于实生苗,良好的活性氧清除机制保护了青椒幼苗细胞膜的完整性,使嫁接苗在NaCl和Ca(NO_(2));胁迫下表现出较高的忍耐力。综上所述,通过嫁接手段可显著提高青椒幼苗根系的抗氧化酶活性,提高活性氧清除能力,降低盐胁迫导致的氧化损伤,提高植株的耐盐性。

Salt stress is one of the abiotic stresses that inhibits crop growth and development. In order to provide theoretical bases for using green pepper grafting cultivation to overcome soil salinization and continuous cropping obstacle, the green pepper ‘Shizhen’ and ‘Hongyingqiang’ were used as rootstocks, and‘Aodaili’ was used as the scion for grafting to study the effects of iso-osmotic stress of 150 mmol/L NaCl and 100 mmol/L Ca(NO_(2));stress on the growth, reactive oxygen metabolism and antioxidant enzyme activities of green pepper seedlings and grafted seedlings. The results showed that NaCl and Ca(NO_(2));stress significantly inhibited the biomass accumulation of green pepper seedlings, increased the contents of O_(2)^(-) and MDA in root and reduced their antioxidant enzyme activity. However, the inhibition degree in grafted seedlings was significantly smaller than that in seedlings, and the inhibitory effect of Ca(NO_(2));stress was more significant. Antioxidant enzyme activities(SOD, POD and CAT) in roots of grafted seedlings were significantly higher than those of seedlings, and the contents of O_(2)^(-) and MDA in roots were significantly lower than that of seedlings. The good active oxygen scavenging mechanism protected the integrity of cell membrane, so the grafted seedlings showed higher tolerance under the stress of NaCl and Ca(NO_(2));. To sum up, grafting could significantly increase the antioxidant enzyme activity in roots of green pepper seedlings, improve the active oxygen scavenging ability, reduce oxidative damage caused by salt stress and improve plant salt tolerance.