NaCl胁迫下2种铁线子属果树叶片的可溶性糖及丙二醛含量变化

Soluble Sugars and MDA in Leaves of Two ManilkaraSpecies under Salt Stress

采用盆栽试验法,以0、2‰、4‰、6‰、8‰NaCl溶液分别对铁线子属果树古巴牛乳树Manilkara roxburghiana(Wight)Dubard、人心果Manilkara zapota(L.)van Royen进行胁迫处理,对植株盐害现象、土壤实际全盐度和叶片可溶性糖、丙二醛含量的变化进行比较。试验结果表明:古巴牛乳树、人心果分别在土壤实际全盐度3.38‰、2.88‰出现2级盐害,在4.28‰、4.05‰时出现3级盐害。2种果树叶片可溶性糖含量变化与NaCl用量梯度呈现正相关,并和对照差异显著。叶片丙二醛含量在2‰、4‰NaCl时和对照差异不显著,在6‰、8‰NaCl时与对照差异显著。试验结果推断:2种铁线子属果树在6‰、8‰NaCl处理时,叶片细胞膜脂过氧化加重;可溶性糖作为渗透调节物质对植物幼苗抵抗NaCl胁迫可能起着重要作用。

Mechanism of the salt tolerance of Manilkara roxburghiana(Wight)Dubard and Manilkara zapota(L.)van Royen was investigated.The potted plants of the two species were watered with 0,2‰,4‰,6‰ or 8‰ NaCl solutions to observe the damages to the seedlings,as well as the induced changes on soil salinity and on the soluble sugars and MDA in the plant leaves by the salt stress.M.roxburghiana and M.zapota showed a Grade II salt damage under 3.38‰ and 2.88‰ NaCl stress,respectively,and a Grade III damage under 4.28‰ and 4.05‰ salt stress,respectively.The soluble sugars in the leaves of the plants increased with increasing concentration of NaCl,and were significantly different from those of Control without the salt stress.It was speculated that,with respect to the cellular osmosis,the soluble sugars might have increased by the plant in response to the presence of salt so as to improve its tolerance to the stress.The contents of MDA also differed significantly from Control under 6‰ or 8‰NaCl stress indicating the presence of a serious membrane lipid peroxidation on the plants.