盐胁迫下接种AM真菌对玉米耐盐性的影响

以玉米品种陕单16号幼苗为材料,用盆栽法研究了不同含盐量(0、0.5、1.0、1.5和2.0 NaCl g/kg)土壤接种AM真菌(Glomus mosseae)对玉米幼苗生物量、盐害级数,以及叶片中电解质透出率、丙二醛、O·2-、H2O2含量和保护酶活性的影响.结果表明:在盐胁迫下,接种AM真菌增加了玉米植株生物量,降低了玉米的盐害级数;菌根植株叶片中过氧化氢酶的活性高于非菌根植株,而过氧化物酶、抗坏血酸氧化酶和多酚氧化酶的活性则为非菌根植株高于菌根植株;超氧化物歧化酶的活性在NaCl浓度为0、0.5和1.0 g/kg时为非菌根植株高于菌根植株,而在NaCl浓度为1.5和2.0 g/kg时则为菌根植株高于非菌根植株;菌根植株叶片中电解质透出率、丙二醛、O·2-和H2O2的含量低于非菌根植株.可见,AM真菌的侵染提高了玉米的耐盐性,缓解了由盐胁迫引起的过氧化胁迫对玉米植株的伤害,但这一缓解作用并不只是通过提高保护酶活性来实现的,可能还存在一些非酶促的调节机制.

Effect of AM Fungi on Salt Resistance of Maize

With the aim of determining whether the arbuscular mycorrhizal(AM) inoculation would affect biomass,salt injury series,electrical permeation rate,contents of malondialdehyde,H2O2 and O-·2,and protective enzyme activities in maize leaves under salt stress,a greenhouse experiment was carried out with or without Glomus mosseae at 5 NaCl levels(0,0.5,1.0,1.5,2.0 g/kg dry substrate).The results showed that the AM inoculation increased maize biomass,decreased salt injury series.Compared with non-mycorrhizal plants,mycorrhizal plants had higher catalase activity and lower activities of peroxidase,polyphenol oxidase and ascorbic acid oxidase;at 0,0.5 and 1.0 g/kg NaCl levels,the superoxide dismutase activity in mycorrhizal plants was lower than that in non-mycorrhizal plants;While,at 1.5 and 2.0 g/kg NaCl levels,the superoxide dismutase activity in mycorrhizal plants was higher;AM fungal colonization decreased the electrical permeation rate and contents of malondialdehyde,H2O2 and O-·2 in leaves.The results presented here indicate that the AM fungal colonization improves the salt resistance of maize plants,and alleviates the deleterious effect of the peroxidation stress induced by salt stress on maize plants not only through improving protective enzyme activities,but also through other non-enzymatic mechanisms.