3种滨藜属植物幼苗叶片对NaCl胁迫的生理响应

以灰白滨藜变种1、灰白滨藜变种2和四翅滨藜的1年生实生幼苗为试验材料,采用沙土盆栽试验,对不同质量浓度(0、0.1%、0.3%、0.5%、0.7%和1.0%)NaCl单盐胁迫条件下3种滨藜属植物幼苗叶片盐害指数、耐盐阈值及生理特性等指标进行了测定。结果表明:盐胁迫提高了3种滨藜属植物幼苗各器官Na+浓度,降低了K+浓度,灰白滨藜变种2较其他2种植物各器官保持了相对较低的Na+和较高K+浓度,有利于维持较高的K+/Na+平衡;随着土壤盐浓度的增加,灰白滨藜变种2叶片受盐害起始浓度、耐盐阈值及耐盐极限浓度均高于灰白滨藜变种1和四翅滨藜,最终确定出灰白滨藜变种1、灰白滨藜变种2和四翅滨藜的耐盐阈值分别为0.59%、0.68%和0.63%;叶片丙二醛含量、细胞膜相对透性随着盐胁迫程度的加剧而增加。经隶属函数综合评价认为3种滨藜属植物耐盐性强弱顺序依次为:灰白滨藜变种2(0.686)＞四翅滨藜(0.532)＞灰白滨藜变种1(0.102);与灰白滨藜变种1相比,灰白滨藜变种2和四翅滨藜各项生理指标特征对盐土环境的适应能力更强。 

Leaf physiological characteristics of seedlings of three Atriplex species under NaCl stress

Atriplex species, such as Atriplex canescens ssp. aptera, A. canescens ssp. canescens var. laciniata and A. canescens, as unique quasi-evergreen shrubs in arid and semi-arid desert area, are of high socio-ecological importance in controlling desertification, improving soil quality in saline land, and supporting local ecological balance. Here we measured salt injury index, salt-tolerant thresholds and physiological characteristics of the first-year seedlings by a salt-stress experiment conducted in pots. In the experiment, the pots were filled with sand and the six salt levels were adjusted to 0 , 0. 1%, 0. 3%, 0. 5%, 0. 7%, and 1. 0% NaCl. The results showed that: 1 ) Na+ increased and K+ decreased in each part of three Atriplex seedlings under salt stress. Compared with A. canescens ssp. aptera and A. canescens, the relatively lower Na+ and higher K+ contents were retained in each part of A. canescens ssp. canescens var. laciniata, which was conducive to keeping higher K+/Na+ balance. 2 ) The initial NaCl concentration with salt stress, salt-tolerance threshold and salt concentration limit of A. canescens ssp.
canescens var. laciniata were higher than the other two plants. 3 ) The salt-tolerance thresholds of A. canescens ssp. aptera, A. canescens ssp. canescens var. laciniata and A. canescens were 0. 59%, 0. 68%, and 0. 63%, respectively. 4 ) With salt stress increasing, MDA content and cytomembrane permeability were consistently increasing. 5) The salt-tolerance thresholds of the three species based on subordinate function comprehensive evaluation were in the order of A. canescens ssp. canescens var. laciniata (0. 686) >A. canescens (0. 532) >A. canescens ssp. aptera (0. 102). It is suggested that A. canescens ssp. canescens var. laciniata has a stronger adaptability to saline soil than A. canescens and A. canescens ssp. aptera.