青海碱茅属植物系统修订

通过对青海省碱茅属植物的研究,修订了青海省碱茅属植物分类系统。首次确认青海省产碱茅属植物3组31种,其中18种为青海新记录。     

碱茅属5个种的同工酶研究

用聚丙烯酰胺凝胶电泳技术对碱茅属的５个种进行过氧化物酶同工酶及酯酶同工酶的研究结果表明，５个种的过氧化物酶同工酶的酶谱差异很小，但酯酶同工酶的酶谱差异较大，５个种中的碱茅与微药碱茅酶谱相同，朝鲜碱茅与热河碱茅酶谱极为相近，而星星草酶谱介于两类之间，为过渡类型。     

种植星星草对盐碱土壤氮素和磷素含量的影响

在盐碱土壤上种植星星草 (Puccinellia tenuif lora)群落后测定土壤氮、磷含量。结果表明 ,星星草在盐碱土壤上生长 2～ 3年后 ,土壤全氮含量、碱解氮含量 ,氨化强度、固氮强度 ,全磷全量、速效磷含量、有机磷含量、无机磷含量都增加 ,且星星草生长 3年比星星草生长 2年的各项指标都有增高的趋势     

盐生植物小花碱茅K+通道PtAKT1基因片段的克隆及序列分析

为研究小花碱茅(Puainellia tenuiflora)K⁺/Na⁺选择吸收分子机制,根据已报道的其他植物AKT1基因的保守序列设计一对简并性引物,以小花碱茅根部总RNA为模板,采用RT-PCR方法克隆出AKT1基因,以期为小花碱茅AKT1全长基因的克隆、表达调控及其作物改良的研究奠定基础。序列分析结果表明:该基因长度大约为1019 bp,编码339个氨基酸;所得序列与GenBank中注册的高等植物AKT1基因序列的同源性均在85%以上,与其他AKT1的氨基酸序列同源性达73%以上。     

芦苇和碱茅耐盐生理特性的比较分析

以芦苇和碱茅作为试验材料,利用沙培的办法培养幼苗,分析测定了盐胁迫下,芦苇和碱茅的质膜相对透性、叶绿素含量以及叶片和根部Na+、K+含量的变化。结果表明,随盐胁迫浓度的增加,两种植物的细胞质膜相对透性均增加,但碱茅的质膜相对透性高于芦苇,叶绿素含量先升高后降低,Na+、K+发生了不同程度的变化,两者具有不同的耐盐机理,芦苇是拒盐植物,碱茅是泌盐植物。     

同德小花碱茅种子发育过程中几个生理指标的变化

采用6种活力测定方法,研究了同德小花碱茅（Puccinellia tenuiflora cv.Tongde）种子发育过程中含水量、种子质量和营养物质等生理生化的变化。试验结果表明,同德小花碱茅种子发育过程中含水量散失速率呈先快后慢的规律,在盛花期后26 d种子达到生理成熟,含水量为27.85%,种子中可溶性糖的含量随种子成熟逐渐减少,而淀粉含量变化则相反。同德小花碱茅种子发育过程中植物内源激素生长素、赤霉素和脱落酸的含量高峰依次出现。本研究表明,种子活力随种子成熟不断增加,在盛花期后26 d达到最高水平。     

PtHAK5, a candidate for mediating high-affinity K+ uptake in the halophytic grass, Puccinellia tenuiflora

Puccinellia tenuiflora is a typical salt-exclu-ding halophytic grass with strong salt-tolerance, which enhances tolerance by restricting Na⁺ influx as well as having a strong selectivity for K⁺ over Na⁺. The HAK5 K⁺ transporters generally modulate effective K⁺ acquisition in plants, especially under low K⁺ condition. In this study, PtHAK5 from P. tenuiflora was isolated by RT-PCR and characterized using yeast complementation. The results showed PtHAK5 consisted of 784 amino acids and shared over 80% homology with the identified high-affinity K⁺ transporter HAK5 from other higher plants. The expression of PtHAK5 rescued the K⁺-uptake-defective phenotype of yeast strain CY162. In conclusion, PtHAK5 is a candidate for mediating high-affinity K⁺ uptake under low K⁺ conditions.     

松嫩平原碱化草甸三种多年生盐碱禾草群落生产特征的分析

采有随机取样方法调查与测定，分析了松嫩平原碱化草甸星星草，朝鲜碱茅，獐毛３种耐盐碱禾草单优群落的生产特征。星星草群落的生殖株在数量和重量上均占绝对比重，成穗率为８８．２％，其重量比率高达９４．７５。朝鲜碱茅群落生殖株的数量少于营养株的数量，成穗率为３９．５％，但生殖株与营养株所占的重量比率无明显差异。獐毛群落生殖株的数量远远少于营养株的数量，成穗率仅为１５．７％。在不同的生育期与密度条件下，獐毛群     

The productivity of salt marsh vegetation at Tollesbury,Essex, and Stiffkey,Norfolk, England

This study presents data on the biomass and net aerial primaryproductivity (NAPP) of two contrasting East Anglian salt marshes.One site was at Tollesbury, Essex where the marshes are of theestuarine type and are subject to marsh degradation and erosionwhile the other site was 130 km to the north at Stiffkey, Norfolkwhere the barrier-type marshes are still actively developing withno signs of erosion. The NAPP was determined by the method ofSmalley with quadrats being harvested monthly with replacement.At the lowest levels at Tollesbury there was Pioneer Marshwhich was dominated by a mixture of Salicornia spp. and Astertripolium. At higher levels at Tollesbury there was LowerMarsh which was dominated by a mixture of Atriplex portulacoides andPuccinellia maritima. Over the four years of the studyPuccinellia became the dominant species following a markeddecrease in the extent and vigour of Atriplex. At Stiffkey theMiddle Marsh was at a much higher level and the vegetation waspredominantly a short dense sward with Atriplex portulacoides,Puccinellia maritima and Limonium vulgare together with smallerquantities of Armeria maritima and Plantago maritima. The meanNAPPs over three years of the Pioneer and Lower Marsh atTollesbury (467 & 519 g m^-2 yr^-1respectively) were similar butin 1993 the NAPPs recorded at Tollesbury were higher than thoserecorded at Stiffkey (625 & 583 compared with 458 g m^-2yr^-1).Smalleys method is difficult to apply to communities wherespecies dominance is variable, especially when dominance isshared between species with markedly different growth patterns.The results for NAPP obtained from the salt marshes at Tollesburyand Stiffkey are discussed in relation to results obtained byother workers from comparable areas in England and theNetherlands. Attention is also drawn to the possibly largerbelow-ground component of production that is frequentlyoverlooked. The importance of salt marshes in relation to othercoastal communities lies in the export of a proportion of theorganic matter produced and this mainly depends on theabove-ground production.     

Na2CO3与NaCl胁迫下星星草幼苗叶绿体保护酶活性的比较

用不同浓度的Na2CO3以及与之各个浓度分别对应等渗的NaCl处理星星草幼苗7 d后,测定幼苗渗透势、pH值、电解质外渗率、超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、谷胱甘肽转移酶(GST)、O2-.产生速率和丙二醛(MDA)含量。当基质渗透势相等时,Na2CO3的碱性盐浓度明显比NaCl的低,而pH值要高的多。与NaCl处理相比,Na2CO3胁迫使星星草幼苗渗透势、叶绿素含量下降幅度更明显。当培养基质渗透势较高时,NaCl和Na2CO3胁迫下的星星草幼苗叶绿体SOD和APX活性都呈上升趋势,随着基质渗透势的降低,酶活性也下降,但NaCl胁迫下星星草幼苗叶绿体保护酶活性比Na2CO3胁迫下的强。而Na2CO3胁迫下的相对电导率、O2-.产生速率和MDA含量高于NaCl胁迫的。这可能与Na2CO3胁迫的pH值较高,渗透调节能力较低,保护酶活性较弱,活性氧清除能力降低有关。