Comparison of Plasma Membrane H^＋-ATPase Activity in Two Ecotypes of Reed （Phragmites communis） Leaves from Different Habitats

Plasma membrane (PM) vesicles of the leaves of two ecotypes of reed (Phragrnites communis Trin.), swamp reed (SR) and heavy salt meadow reed (HSMR) growing in the desert region of Northwest China, were purified by two-phase partitioning and the properties of their PM H^ -ATPases (EC 3.6.1.35) were compared. The specific activity of this enzyme was greater in HSMR than in SR and the Km lower (1.27mmol/L in SR and 0.30mmol/L in HSMR), and the Vmax of ATP hydrolysis activity showed no significant difference between the two ecotypes. The PM H^ -ATPase was more sensitive to denaturing temperatures in HSMR than in SR, and the pH profile also showed a slight difference, suggesting that the catalytic mechanism of this enzyme was different in HSMR compared with that in SR. The p-nitrophenyl phosphate (PNPP) hydrolysis activity of H^ -ATPase was higher in HSMR than in SR at low concentrations of PNPP, but showed no difference at high PNPP concentration. The Km for PNPP hydrolysis was 3.61mmol/L and 1.92mmol/L in SR and HSMR, respectively. And the Vmax of PNPP hydrolysis showed no significant difference in the two reed ecotypes. An experiment with the inhibitor vanadate showed that the catalytic mechanisms of the phosphatase domain of the ATPase were different in the two ecotypes. The data obtained following trypsin treatment showed a difference in the enzyme activity pattern, suggesting that there existed a possible change in the C-terminus of the ATPase, either in the structure or in the property or both of them. In addition, compared with SR, the ATP-dependent H^ pumping activity of ATPase and the coupling between proton transport and ATP hydrolysis in HSMR were increased. These results indicated that the properties of PM H^ -ATPase were changed in HSMR with compared to those in SR, which might include enzyme modifications and different isoforms expressed. The alterations of the properties of this enzyme might be an adaptive response to the habitat.     

不同品种(系)牧草镉修复能力综合评价

该研究选用3种高丹草、2种苏丹草、2种杂交狼尾草、一年生黑麦草和多年生黑麦草共9个牧草品系，采用盆栽试验，设置0(CK)、10(Cd10)、20 mg/kg(Cd20)镉胁迫处理，考察不同品系的生长指标、镉含量和富集指标，运用极差化法和主成分分析建立综合评价模型，通过计算各牧草在模型中的综合得分，筛选出最适宜实地修复的牧草，探究不同品种和不同品系牧草的镉修复能力差异，建立Cd污染土壤植物修复能力评价体系，发掘兼顾富集量和后处理的镉污染土壤植物修复资源。结果表明：(1)镉胁迫会不同程度降低牧草的株高和生物量，其中江苏苏丹草在Cd10和Cd20中的耐胁迫能力均较强；(2)在Cd10和Cd20处理下，一年生和多年生黑麦草均具有较高的地上部和地下部Cd含量，高丹草的3个品系在Cd含量和Cd积累量两方面存在较大差异；(3)在Cd10和Cd20处理下，高丹草和黑麦草的富集指标表现优异，且富集指标在高丹草品系间存在较大差异；(4)2个镉质量分数处理下综合评价得分最高的均是一年生黑麦草，其次为高丹草。研究表明，参试牧草对镉胁迫均有较强的耐受性，但耐受能力和富集能力在品系间存在明显差异，并以高丹草品系间差异最大；一年生黑麦草能耐受20 mg/kg以下镉胁迫，且生物量较小，对镉有较强的浓缩效应，可作为镉污染土壤实地修复的可靠材料；综合评价模型可作为镉污染修复植物资源筛选的可靠方法。     

施用增产菌对豆科牧草增产效果的研究

施用增产菌对豆科牧草增产效果的研究魏书兰，于海清（朝阳市草原工作站，１２２００）（喀左县草原工作站）增产菌是一种新型的植物生长调节剂，具有促进植物生根、发芽、开花、茎叶生长等多种功能，能够提高植物抵抗病毒侵袭和不良环境影响的能力。近年来已在多种农作物...     

黑麦（Secal cereale L.）联会复合体核型与染色体核型的比较研究

国内首次以“胜利”黑麦品系为材料，在电镜下观察联会复合体并分析了联会复合体核型。在同染色体核型比较后，认为“胜利”黑麦存在着两个可能的易位：１Ｒ长臂的一小段易位到６Ｒ短臂；４Ｒ长臂向２Ｒ长臂易位三单位长度，使４Ｒ长臂变成短臂。从而判断“胜利”黑麦为易位杂合体。这个研究方法可以在植物实验分类学研究中得到应用。     

Water Supply Changes N and P Conservation in a Perennial Grass Leymus chinensis

Changes in precipitation can influence soil water and nutrient availability, and thus affect plant nutrient conservation strategies. Better understanding of how nutrient conservation changes with variations in water availability is crucial for predicting the potential influence of global climate change on plant nutrient-use strategy. Here, green-leaf nitrogen （N） and phosphorus （P） concentrations, N- and P-resorption proficiency （the terminal N and P concentration in senescent leaves, NRP and PRP, respectively）, and N- and P-resorption efficiency （the proportional N and P withdrawn from senescent leaves prior to abscission, NRE and PRE, respectively） of Leymus chinensis （Trin.） Tzveh, a typical perennial grass species in northern China, were examined along a water supply gradient to explore how plant nutrient conservation responds to water change. Increasing water supply at low levels （〈 9000 mL/year） increased NRP, PRP and PRE, but decreased green-leaf N concentration. It did not significantly affect green-leaf P concentration or NRE. By contrast, all N and P conservation indicators were not significantly influenced at high water supply levels （〉 9000 mL/year）. These results indicated that changes in water availability at low levels could affect leaf-level nutrient characteristics, especially for the species in semiarid ecosystems. Therefore, global changes in precipitation may pose effects on plant nutrient economy, and thus on nutrient cycling in the plant-soil systems.     

禾本科目蔗亚族一新属

８０年代初期，我们在云南采到５号标本，解剖观察认是甘蔗亚族（Ｓａｃｃｈａｒｉｎａｅ）植物。再进一步查对，要把它放入这个亚族中的任何一属均觉不妥，故另立新属与新种，本新属与芒属（Ｍｉｓｃａｎｔｈｕｓ）似有亲缘关系。     

增产菌对朝阳地区豆科牧草增产效果的试验研究

增产菌(YIB)—植物微生态制剂,是植物保健益菌。我们分别用20ml/亩、40ml/亩、60ml/亩拌“公农一号”紫花苜蓿种子,及用5、8g/亩喷施三年生“公农一号”紫花苜蓿和拌沙打旺种子,其结果是对豆科牧草的株高、产草量。有明显地提高,增加了人工草地的经济效益。关于增产菌在豆科牧草方面的应用目前尚未见过报导。     

不同种植模式下重金属污染对牧草叶片光合特性和重金属含量的影响

为探索不同种植模式下重金属污染对牧草生理特性的影响,皇竹草(Pennisetum sinese)、黑麦草(Lolium perenne)和龙须草(Juncus effusus)采用单作和间作模式,研究了重金属污染对其叶片光合参数、光合色素和重金属含量的影响.结果表明,与单作相比,间作下皇竹草叶片的叶绿素(Chl)a、C...     

牧草盲蝽空间分布型及其应用技术研究

牧草盲蝽一代成虫在棉田呈聚集分布,其聚集原因是由环境作用所致。当t=1.64 D=0.2时,其最适抽样数为:N=92.7441/x+46.8797。若防治指标为0.1头/株,则最大抽样数为975株,防治的上下限为:T_9(N)=0.1N±0.7461N~(1/2)。田间调查时,可用有虫株率对平均密度进行简易估计,其公式为: x=1.4219[-ln(1-p)]~(1.0646)。