盐生植物对滨海盐渍土生物改良的研究进展

对比盐碱地改良技术的物理改良、化学改良和生物改良方法,在证明生物改良方法优势的基础上,综述不同盐生植物种类对盐碱地的生物改良效果。     

盐胁迫下野大麦耐盐生理机制初探

以盐生植物野大麦、甜土植物中国春小麦为材料,研究了NaCl胁迫对野大麦、小麦幼苗叶片质膜透性、含水量、地上和根部离子含量、脯氨酸含量、磷酸烯醇式丙酮酸羧化酶(PEPCase)活性的影响。结果表明,随盐胁迫浓度增加,野大麦的细胞膜透性、Na 含量、脯氨酸含量、Na /K 、PEPCase活性增加,含水量、K 含量下降;但在相同盐胁迫条件下野大麦地上部和根部Na 含量明显低于小麦,而根中K 含量高于小麦,表明野大麦可能具有拒绝吸收Na 和维持高K 含量的能力;野大麦的脯氨酸含量增加幅度小于小麦,表明在盐胁迫下野大麦不是通过脯氨酸的积累来达到体内渗透平衡的;野大麦PEPCase活性增加明显高于小麦,说明提高光合效率可能是野大麦实现盐适应的主要措施之一。     

盐生植物根际微生物对含盐环境污染修复展望

盐对微生物生长繁殖的抑制性增加了高盐情况下的污染物的生物修复难度。本文总结了盐度对微生物生长状况影响,分析了盐生植物对其根际微生物耐盐能力和污染物去除能力的作用,并展望了盐生植物在高盐环境条件下对污染修复的潜力。     

Analysis of phenotypic and genetic polymorphism among accessions of saltgrass (Distichlis spicata)

Morphological and genetic analyses were applied on 37 saltgrass (Distichlis spicata) accessions collected from distant locations throughout the American continent in order to: 1) develop and identify morphologic and genetic profiles for the saltgrass genotypes; 2) characterize the genetic distance among saltgrass accessions within the given germplasm collection; and 3) identify a possible linkage between patterns of genetic and eco-geographical parameters. Analysis based on 70 RAPD markers revealed broad polymorphism among the genotypes and enabled their individual characterization. A UPGMA dendrogram clustered the genotypes into groups according to a general pattern of their geographical origin. Yet, only the group of Californian accessions was significantly distinct from other groups, as determined by ² tests. Various statistical analyses indicated that only minor genetic differences existed between seashore and desert saltgrass genotypes, supporting that these two eco-geographical types belong to the same species, Distichlis spicata. Our results suggest that genetic interactions exist between geographically distant saltgrass populations, in spite of the dominance of clonal reproduction in this species. The contribution of dioecy, seed production, and epizoochory to the distribution patterns of saltgrass is discussed at the geographic and at the genetic levels.     

盐生植物耐盐相关基因克隆的研究进展

从渗透胁迫相关的基因、离子胁迫相关的基因和次级胁迫相关的基因几个方面综述了盐生植物耐盐碱基因克隆的研究进展。     

新疆盐生植物区系初探

根据野外实际调查和文献查阅，初步收集了新疆盐生植物共305种15变种7亚种，隶属38科124属，分别占新疆种子植物区系科、属、种的38．0％、17．3％和8．9％，约占中国盐生植物总数的60％。其中约35％的种未被《中国盐生植物》收录，约1／2的种未被“世界盐生植物数据库”收录。盐生植物中约63．9％的种集中分布于藜科、菊科、禾本科和豆科中，多数建群植物为中亚、亚洲中部或地中海地区盐生植物区系成分，盐生植被的旱生特性明显。     

旱盐互作对盐地碱蓬生长及其渗透调节物质的影响

采用盆栽土培的方法,研究了不同干旱条件下盐胁迫对盐地碱蓬生长及其渗透调节物质的影响.结果表明:适量NaCl可提高干旱条件下盐地碱蓬的生物量和植株含水量,缓解其干旱胁迫.盐分改变了干旱条件下盐地碱蓬的渗透调节物质,随着盐浓度的增加,叶片中Na 、Cl-的积累增加,而叶片中的K 积累减少;干旱条件下,叶片Na 、Cl-以及K 的积累增加,增强了盐地碱蓬在干旱条件下的渗透调节能力.叶片中脯氨酸的积累随着土壤含盐量和土壤干旱程度的增加而增加.     

甜菜碱在盐生植物中的作用

甜菜碱是植物重要的有机渗透调节物质之一,甜菜碱合成酶基因被认为是最重要和最有希望的胁迫抗性基因之一.阐述了甜菜碱在盐生植物中的功能、基因工程操作现状,并展望了该领域的研究方向.     

盐生植物海蓬子的利用价值与开发前景

介绍了新兴保健蔬菜海蓬子的生长习性、营养价值、医疗保健作用及在食品、饲料等行业中的应用,并阐述了其开发前景。     

Puccinellia tenuiflora Exhibits Stronger Selectivity for K+ over Na+ than Wheat

Abstract

The characteristics of selectivity for K⁺ over Na⁺ by the roots of the halophyte Puccinellia tenuiflora were investigated in comparison with the glycophyte wheat (Triticum aestivum). Under various NaCl concentrations, the concentrations of K⁺ in the shoots of P. tenuiflora were 16–24% lower than those of wheat, whereas the concentrations of K⁺ in Puccinellia roots were 2.8–4.0 times higher than those of wheat. In 200 mM NaCl, the concentrations of Na⁺ in shoots of P. tenuiflora and wheat were similar under high K⁺ levels, but the concentrations of Na⁺ in wheat were 1.6 times higher than those in Puccinellia under low K⁺ levels. The concentrations of K⁺ in roots of P. tenuiflora were 1.5–2.0 times higher than those of wheat under low K⁺ levels. Formulas are given for calculating net selective absorption (SA) capacity and selective transport (ST) capacity by roots for K⁺ over Na⁺. We interpret SA as the net capacity of selectively absorbing K⁺ over Na⁺ by epidermal and cortical cells of whole plant roots into the root symplast. ST could reflect the net capacity of selection for K⁺ over Na⁺ transport from whole root stelar symplast to the xylem vessels. The lower ST value of P. tenuiflora might be the reason for accumulation of K⁺ in its roots. The SA values of P. tenuiflora and wheat were approximately equivalent in the low-affinity K⁺ uptake range. The SA values of the former were about two times higher than that of the latter in the high-affinity K⁺ uptake range, showing the root high-affinity K⁺ uptake system of the halophyte P. tenuiflora has a stronger capacity for K⁺ uptake.