镉胁迫对不同繁穗苋种质萌发和生长的影响

Effect of cadmium stress on seed germination and growth of Amaranthus cruentus germplasms from different locations

为评价不同地理来源繁穗苋(Amaranthus cruentus)种质的耐镉特性并比较其耐镉性差异,丰富修复镉污染土壤植物的物种组成,并为选育耐镉繁穗苋新品种提供材料,本研究选用16份繁穗苋为试验材料,采用种子萌发试验,分析镉胁迫下繁穗苋种子的萌发特性,采用隶属函数和聚类分析对其耐镉性进行综合评价。结果表明,在80μmol·L^(-1)镉浓度胁迫下,16份不同地理来源的繁穗苋均表现出较强的耐镉性,其种子发芽势、发芽率、胚芽长和发芽指数均与对照差异不显著,但镉胁迫显著抑制了胚根长和活力指数(P <0.05)。聚类分析表明,8份种质(Ace655、Ace631、Ace628、Ace617、Ace575、Ace650、K472、K112)为敏感型,其特征为大部分种质相对胚根长均小于29%;7份种质(Ace671、Ace689、Ace568、Ace666、Ace621、Ace651、Ace613)为耐镉型,其特征为大部分种质相对胚根长为29%~35%;仅有1份种质(R104)为极端耐镉型,其特征为生长萌发所测指标均较高。

This study aimed to evaluate and compare the cadmium tolerance of Amaranthus cruentus germplasms from different geographical sources, enrich the phytoremediation species for cadmium-contaminated soil, and provide materials for breeding new cadmium-tolerant A. cruentus varieties. We used 16 A. cruentus varieties as experimental materials and a seed germination experiment to investigate the germination characteristics of A. cruentus seeds under cadmium stress.Membership function and cluster analysis methods were used to comprehensively evaluate the cadmium tolerance of A.cruentus. The results revealed that the 16 varieties showed strong cadmium tolerance at 80 μmol·L^(-1) cadmium concentration.In addition, the germination potential, germination rate, germ length, and germination index of the control and cadmiumtreated seeds were not significantly different for all 16 varieties;however, the radicle length and vigor index were significantly lower in the cadmium-treated seeds than in the control seeds(P < 0.05). Genus analysis revealed that eight germplasms(Ace655, Ace631, Ace628, Ace617, Ace575, Ace650, K472, and K112) were of the cadmium-sensitive type,indicated by < 29% of relative radicle length of most germplasms. Seven germplasms(Ace671, Ace689, Ace568, Ace666,Ace621, Ace651, and Ace613) were of the cadmium-tolerant type, indicated by the relative radicle length of most germplasms between 29% and 35%. Only one germplasm(R104) was extremely cadmium-tolerant, indicated by high values of measured indicators of growth and germination.