4种藜科植物萌发期耐盐性

Comprehensive evaluation of salt tolerance among four species of Chenopodiaceae at the germination stage

以4种野外采集的藜科植物盐爪爪(Kalidium foliatum)、里海盐爪爪(K. caspicum)、盐节木(Halocnemum strobilaceum)、盐穗木(Halostachys caspica)种子为试验材料,进行不同浓度[0 (CK)、100、200、300、400、500、600 mmol·L^(-1)] NaCl胁迫下的种子萌发试验,测定萌发率、萌发势、萌发指数、活力指数、胚根及胚芽长,分析不同盐浓度对4种植物种子萌发的影响,明确各指标耐盐阈值,并采用隶属函数法对4种植物耐盐性进行综合评价。结果表明,随盐浓度升高,除盐穗木种子萌发指数、活力指数与盐节木的活力指数呈先升后降趋势外,其余3种植物的萌发率、萌发势、萌发指数与活力指数均呈递减趋势;且除里海盐爪爪外,其余3种植物在低盐胁迫(<100 mmol·L^(-1))下的胚根长与胚芽长均高于对照。盐穗木萌发期各指标耐盐阈值最高,为307.44~836.00 mmol·L^(-1),里海盐爪爪最低,在300mmol·L^(-1)的NaCl溶液中种子萌发已受到完全抑制;6项指标耐盐阈值差异较大,其中萌发势、活力指数萌发阈值较低,而萌发率萌发阈值较高。隶属函数综合分析表明,4种植物耐盐性排序为盐穗木>盐节木>盐爪爪>里海盐爪爪。

We investigated seed germination of four species of the subfamily Chenopodiaceae, including Kalidium foliatum,Kalidium caspicum, Halocnemum strobilaceum, and Halostachys caspica, under various salt stress conditions(Na Cl concentration of 0, 100, 200, 300, 400, 500, 600 mmol·L^(-1)). The germination rate, germination potential, germination index,vigor index, and the length of radicle and plumule were measured to understand the salt tolerance threshold of the species.Further, a comprehensive evaluation of salt resistance by subordinate function method was conducted considering the technical reference for saline grassland improvement. The results showed that with the increasing salt concentration, the germination rate and potential, as well as germination and vigor indices of three of the four species, showed a decreasing trend. In contrast, the seed germination index, vigor index of H. caspica, and vigor index of H. strobilaceum, initially showed an increasing trend and eventually a decreasing trend. The radicle and plumule lengths of the species except K. caspicum were higher than those of the control group under low salt stress(< 100 mmol·L^(-1)). At the germination stage, the salt tolerance threshold of H. caspica was the highest(307.44~836.00 mmol·L^(-1)), and that of K. caspicum was the lowest. The germination of germ seeds was completely inhibited under 300 mmol·L^(-1)NaCl. Among the six indices, the thresholds of germination potential and vigor index were the lowest, whereas that of the germination percentage was the highest.According to the comprehensive analysis of membership function, the salt tolerance order of the four species was H. caspica >H. strobilaceum > K. foliatum > K. caspicum.