胡杨茎木质部解剖结构与水力特性对干旱胁迫处理的响应

分析干旱胁迫下胡杨(Populus euphratica Oliv.)茎木质部解剖结构与水力特性的变化对解读其抗逆性机理具有重要意义.本文采用水分控制试验,分析胡杨幼株茎木质部解剖结构和水力特性对不同土壤干旱胁迫处理的响应.结果表明:在解剖结构方面,随着干旱胁迫的加剧,胡杨茎木质部导管密度呈极显著减小(P＜0.01)趋势,而导管内径、导管壁厚度、管壁机械强度呈极显著增大(P＜0.01)趋势,穿孔直径和纹孔直径显著增大(P＜0.05);但导管分子形态却没有发生显著变化,都具有孔纹式和螺纹式两种类型,其中纹孔多为具缘纹孔,呈互列式排列,端壁穿孔为单穿孔类型,并具有螺纹加厚现象;在水力特性方面,随着干旱胁迫的加剧,胡杨茎的木质部比导率(Ks)和自然栓塞程度(PLC)呈显著增加趋势(P＜0.05).为了适应干旱的环境,胡杨茎木质部结构和水力特性发生相应的变化,一定程度上弥补了干旱胁迫所带来的不利影响.     

缺钙对不同钙效率番茄幼苗钙吸收及幼茎解剖结构的影响

采用两个钙效率有较大差异的番茄品种(04,05)研究了缺钙胁迫对幼苗钙素吸收动力学特性、钙在体内的吸收和分配及幼茎解剖结构的影响。结果表明,正常供钙下不同钙效率番茄品种存在吸钙速率的基因型差异,钙低效品种04钙高效品种05,经过缺钙胁迫后重新吸收钙的速率仍然以0405。正常供钙下,钙低效品种04生长量、钙吸收量均显著高于钙高效品种05,而缺钙处理下植株生长量、钙吸收量、钙含量显著低于05。缺钙下两品种的根冠比增加,05增加程度高于04。正常供钙下两品种表皮细胞、薄壁细胞和形成层细胞形状大小匀称,排列紧密,04茎木质部导管数较多;缺钙使两品种幼茎形成层细胞发育受到影响,尤以04影响显著,表明缺钙胁迫对04品种结构的影响远远高于05。     

地枫皮营养器官解剖结构特征及其叶片结构的生态适应性

为了明确地枫皮的结构特征及其在石灰岩山顶和山腰疏林间两种环境下生长的叶片解剖结构的差异,本研究采用石蜡切片和半薄切片对地枫皮营养器官进行解剖观察并评价了叶片结构对不同生态环境的响应.结果表明：地枫皮根中次生维管组织发达,木射线和韧皮射线明显.老茎的次生构造中,皮层贮藏物质丰富,内有大的石细胞群,韧皮射线和木射线明显;而髓细胞内含有大量晶簇和少量单晶.在叶片横切面观上,叶为异面叶,表皮细胞一层,上表皮无气孔分布,主脉中薄壁细胞中分散有石细胞.叶片解剖结构显示,随海拔高度上升,地枫皮趋向于旱生植物的特点,其主要表现在叶片表皮细胞外壁角质层加厚,栅海比增加、海绵组织排列由紧密变疏松.另外,根皮、茎皮和叶肉中都分布有大量油细胞.     

水分胁迫下酿酒葡萄叶片细胞组织超微结构变化

以一年生盆栽酿酒葡萄"梅鹿辄"(Merlot Mission,Vitis vinifera L.)为试材,研究了在不同水分胁迫强度下的细胞结构和组织结构的变化.结果表明,随着水分胁迫强度的增大,叶片厚度有增厚的趋势,在严重胁迫下的葡萄叶片厚度反而与对照叶片的厚度无显著差异.随着胁迫过程的延续,叶绿体向细胞内部膨胀,类囊体肿胀弯曲加剧,直至消失,排列错综复杂无规律性.叶绿体膜与类囊体膜模糊不清,甚至出现解体现象.基质片层溶解,基质中出现了较大的透明腔.在严重胁迫时,部分叶绿体挤入细胞中间部位.研究观察到叶绿体体积大小与其中嗜锇颗粒的数量和大小有关.     

不同水分条件下水稻根解剖结构的比较分析

在旱作和淹水两种培养方式下,研究了5种基因型水稻(Oryza.sativa.L.)(常规粳稻、杂交粳稻、常规籼稻、杂交籼稻和旱稻)幼苗根系解剖结构的差异。结果表明,两种水分条件下,水稻根通气组织的形成和皮层厚壁细胞的形态均存在基因型差异。5种基因型间,淹水条件下杂交粳稻根形成通气组织的时间最晚,根皮层厚壁细胞形态上的差异在常规粳稻和常规籼稻之间表现得更为明显;旱作条件下旱稻的根通气组织形成较其他基因型晚,常规粳稻根皮层厚壁细胞排列疏松,细胞壁加厚程度小。与淹水条件相比,旱作条件下杂交稻根通气组织形成较迟,常规粳稻根皮层厚壁细胞排列较疏松。     

单、双瓣茉莉营养器官解剖结构特征及其生态适应性研究

对相同生境栽培的单、双瓣茉莉根茎叶等器官解剖结构特征研究结果表明 ,与单瓣茉莉相比 ,双瓣茉莉具有根、茎各薄壁组织淀粉粒积累量较多 ,茎次生木质部导管内无侵填体 ,茎皮层细胞层多达 2～ 4层 ,气孔器较小、密度较大且位置更下陷 ,气孔器面积 叶表面积值较小 ,叶片角质层较厚且叶肉细胞较小 ,栅栏组织厚度 叶肉组织厚度值较大 ,栅栏组织细胞排列更紧密等叶片结构特征 ,这可能是双瓣茉莉更适应低温和干旱生境的原因之一     

石山棕营养器官的解剖结构特征

研究了石山棕营养器官的解剖结构,结果表明,石山棕营养器官具有发达的保护组织、输导组织、光合组织和机械组织。主要表现为:叶表皮角质膜发达,复表皮富含丹宁,栅栏组织发达(2.5层);根原生木质部束数多(31原),导管和筛管多,大量的薄壁细胞的细胞壁在根成熟后转化为机械组织;茎、叶柄和叶脉的木质部、韧皮部发达,维管束鞘细胞层次多并高度次生木化加厚,茎、叶柄具较多纤维;根、茎的栓化层发达。石山棕的营养器官具有良好的适应干旱、高温、瘦瘠的岩溶石山环境的生态结构,     

雷竹对铅胁迫的生理响应及其修复效率研究

通过水培和土培实验,分析雷竹在铅胁迫下对铅的吸收、富集、转运能力及其光合水平变化和超微结构表征。结果表明,叶、茎、根在水培铅含量为100μmol/L条件下最大富集量分别为6 706,3 710,26 388mg/kg;在土培铅含量为1 200mg/kg条件下叶、茎、根最大富集量分别为63,101,595mg/kg;通过观察雷竹叶绿素荧光结果发现,Y(Ⅱ)与ETR值降低,说明铅胁迫抑制雷竹光合产物的形成和电子传递的能力,但是对植物的生物量影响不显著;通过透射电镜(TEM)观察铅胁迫下雷竹叶片的超微结构,发现低浓度的铅对植物组织破坏不明显,高浓度的铅使雷竹部分细胞壁变形、叶绿体膜消失或部分断裂,片层结构模糊不清。     

钾对不同钾效率棉花基因型叶片解剖结构的影响

以钾高效高潜基因型HG103和低效低潜基因型LG122为材料,在盆栽条件下研究了钾对不同棉花基因型叶片解剖结构的影响。结果显示:花铃期施钾条件下HG103上部叶主叶脉的上、下表皮细胞排列较LG122紧密和整齐,而下部叶片则相反;缺钾后HG103上部叶主叶脉比LG122发育得好;HG103叶脉维管束木质部具有较多导管数,利于养分和水分等的运输,而LG122木质部导管数相对较少;HG103上部叶叶脉的韧皮部比LG122较为发达,利于光合产物运输。花铃期施钾条件下HG103上部叶的叶肉细胞结构与LG122差别不大,下部叶的栅栏组织则没有LG122排列的整齐。缺钾时,HG103上部叶叶肉的上表皮细胞比LG122排列的较为整齐,栅栏组织和海绵组织形状较规则;而下部叶LG122栅栏组织和海绵组织比HG103分化得好。     

低温对不同耐冷性水稻品种秧苗生理特性及根尖解剖结构的 影响

以秧苗期耐冷性不同的2个水稻品种湘早籼45和三七十萝为材料,利用光照培养箱分别设适温（25℃,CK）和低温（10℃）两个处理,研究低温下水稻秧苗生理特性及根尖解剖结构的变化,以探明低温对水稻秧苗的影响机理。结果表明,与对照相比,低温下幼苗总根数、最长根长、根鲜重、根干重、根系总吸收面积、活跃吸收面积和根系活力下降,且随着处理时间的延长降低幅度增大,冷敏感品种湘早籼45幼苗的降幅大于耐冷品种三七十萝;低温下根系SOD活性、POD活性表现为先增加后降低的趋势,根系相对电导率、MDA含量增加,耐冷品种三七十萝根系SOD活性、POD活性、相对电导率、MDA含量变幅小于冷敏感品种湘早籼45;低温下根系分泌物游离氨基酸含量和可溶性糖含量呈现先增加后降低的趋势,耐冷性品种三七十萝变幅高于冷敏感品种湘早籼45;低温下冷敏感品种湘早籼45根尖薄壁细胞形状不规则,排列疏松,细胞间隙大,维管束结构不清晰,木质部排列紊乱,而耐冷品种三七十萝低温下根尖薄壁细胞形状较规则,细胞排列较紧密,细胞间隙小,维管束结构较清晰,木质部和韧皮部清晰可见。研究结果说明水稻幼苗受低温激发通过诱导不同生理和形态变化以应对低温的影响。     

Long-Term Effects of Aluminum and Cadmium on Growth,Leaf Anatomy,and Photosynthetic Pigments of Cotton

Aluminum (Al) and cadmium (Cd) are two elements that contaminate soil in different ways as waste products of some industrial processes and that can be tolerated by some plant species in different concentrations. In this study, growth parameters of leaves and stems (fresh and dry weights, stem lengths, leaf surface area, and lamina thickness), anatomical changes in leaves (lower and upper epidermis, stomata and mesophyll tissue), and photosynthetic pigment contents (chlorophyll a and b, total chlorophyll, and carotenoids) were investigated in cotton (Gossypium hirsutum L. cv. Nazilli 84S), which was treated with Al and Cd for 3 months. Cotton seedlings were grown in greenhouse conditions and watered with Hoagland nutrient solutions, which contained 0, 100, and 200 μM aluminum chloride (AlCl₃) and cadmium chloride (CdCl₂). It was observed that reduced soil pH positively affected many parameters in cotton plants. Aluminum accumulation was greater in leaves than stems while the opposite was true for Cd accumulation. Leaves and stems of cotton plants treated with 100 and 200 μM Al and Cd showed slight growth changes; however, high concentrations of Al (200 μM) caused significant reductions in leaf area and leaf fresh weight, whereas stem fresh weight decreased with 200 μM Cd treatment. Anatomical parameters were mostly affected significantly under both concentrations of Al and Cd solutions (100 and 200 μM). The results revealed that the anatomical changes in the leaves varied in both treatments, and the long-term effect of the tested metals did not include harmful effects on anatomical structures. Moreover, the variations could be signals of tolerance or adaptive mechanisms of the leaves under the determined concentrations.     

煤矿区生态储存估算及其对土地利用的综合响应评价

为对煤矿区生态储存估算及其对土地利用的综合响应进行评价,以山西省位于长河流域的晋煤集团11个集中连片煤矿区为例,在生态服务功能理论的基础上,通过收集研究区10a的土地利用类型以及矿区与非矿区的相关数据,分析各类土地利用类型的面积、分布和变化方向,并建立评价指标体系以估计不同时期的生态储存,进而得出煤矿区基于煤炭开采的生态储存的响应。研究结果:研究区整体的生态储存呈下降趋势,除了天安圣华,其他煤矿区的生态都出现不同程度的退化,且矿区的退化速度远高于非矿区;12个区域中(11个煤矿区和1个非煤矿区)有一半以上区域的生态储存等级为第3级,研究区11个煤矿区的生态储存能力普遍较高,生态改善的可能性较大,可为煤矿区生态保护规划以及相应的管理提供基础数据和应用借鉴。     

云南会泽废弃铅锌矿区和非矿区中华山蓼根际真菌镉耐性研究

采用常规、含Cd2＋和含Pb2＋的马丁氏培养基,对云南省会泽县废弃铅锌矿区和非矿区中华山蓼（Oxyria sinensis Hemsle）根际真菌进行分离,将分离的菌株接种到含不同浓度（0、0.05、0.5和5mmol·L-1）Cd2＋的马铃薯葡萄糖培养液中,研究和比较了废弃铅锌矿区和非矿区中华山蓼根际真菌的镉耐性。结果表明,Cd2＋显著抑制铅锌矿区和非矿区中华山蓼根际真菌的生长;Cd2＋对常规、含Cd2＋和含Pb2＋的马丁氏培养基分离的铅锌矿区中华山蓼根际真菌的EC50平均值和最大值均明显大于非矿区,表明铅锌矿区中华山蓼根际真菌对Cd2＋的耐性强于非矿区,采用含Cd2＋培养基,从铅锌矿区中华山蓼根际分离出的真菌Cd2＋耐性最强。     

黔西煤矿区周边土壤重金属形态特征、污染评价及富集植物筛选

[目的]研究黔西某煤矿区周边土壤重金属污染情况、重金属形态潜在风险及其周边重金属富集植物,为当地的重金属污染防治提供科学依据。[方法]采用潜在生态风险评价及模糊数学法的两种评价方法(单因素决定模型和加权平均模型)对煤矿区及非煤矿区土壤进行重金属生态风险评价,对影响土壤肥力的土壤理化指标进行检测,利用风险评估编码法对重金属形态进行分析,并采用生物富集系数法对煤矿区周边富集重金属植物进行筛选。[结果]煤矿区Hg,Cd,As,Zn,Cr及Ni平均值含量分别是背景值的2.47,3.65,2.00,1.23,1.74,1.69倍。煤矿区潜在生态危害趋势为:CdHgAsNiCrPbZn。模糊数学法单因素决定模型评价显示,非煤矿区污染大于煤矿区,加权平均模型则反之。煤矿区Cd,Cr,Cu,Mn,Ni,Pb及Zn潜在风险指数分别为69.17%,7.97%,8.24%,40.10%,45.29%,53.70%及29.90%。蜈蚣草对As富集系数大于1.00,火棘、构树、盐肤木、马桑、凤尾蕨及金丝梅等对Cd富集系数大于1.00,马桑及白蒿对Pb富集系数大于1.00。[结论]煤矿区存在重金属污染,以Cd,As,Hg较为严重。煤矿区周边土壤中重金属对环境构成的潜在风险顺序为:CdPbNiMnZnCuCr。对当地而言,蜈蚣草可作为煤矿区周边修复As污染的先行植物,凤尾蕨可作为修复Cd污染的先行植物,马桑可作为修复Pb污染的先行植物。     

基于二分类Logistic回归模型土壤Cu污染风险预测

土壤重金属来源广泛,其污染风险受到多种因素综合影响,常与影响因素存在非线性关系。Logistic回归法可克服普通线性回归法的应用限制,对土壤污染风险的影响因素识别和污染风险预测中具有良好的应用潜力。以浙江某人类活动强烈影响区域土壤为研究对象,选择坡度、坡向、海拔、人口密度、道路距离、非矿工业加权距离和到矿区距离为自变量,以土壤Cu污染风险分类为因变量,采用二分类Logistic回归模型,识别土壤Cu污染风险影响因素并预测污染风险。结果表明:土壤Cu污染风险受到人口密度、矿点距离、道路距离和非矿工业加权距离的影响显著,但土壤Cu污染风险与人口密度、矿点距离和道路距离均无简单线性关系,密集矿点的叠加作用显著改变了距离对土壤污染风险的影响。区内土壤Cu污染高风险区主要位于铜矿采选及其尾矿库影响区域,中风险区位于破碎带金矿、铁矿区及交通运输影响范围内,低风险区位于低密度人口和高密度人口区域。     

Effects of Manganese on Uptake and Translocation of Nutrients in a Hyperaccumulator

The effects of manganese (Mn) on the growth and Mn-induced changes in nutrients uptake and translocation in Mn hyperaccumulator Phytolacca acinosa was investigated in this study. Results showed that high Mn (5000 μ M) in culture solution lead to typical Mn toxicity symptoms in leaves of P. acinosa and decrease of dry matter accumulation in shoots whereas there are no obvious toxicity symptoms and significant decrease of dry weight in roots. Manganese accumulation in roots, stems, and leaves increased with the increment of Mn concentration at the medium level. Calcium (Ca), magnesium (Mg), and iron (Fe) concentration in organs of P. acinosa decreased as the Mn concentration in the nutrient solution increased, but the Ca and Mg concentrations were still at a normal level and the Fe concentration at a sufficient level when compared with the normal plants. The Zn concentration affected by higher Mn level occurred only in roots of P. acinosa and the P concentration affected only in stems, whereas there were no significant influences of excess Mn on the potassium (K) and copper (Cu) concentration in organs of P. acinosa.     

采煤沉陷区冻结滞水消融过程中土壤水分变化规律

冻结滞水的倒置富水性和双向融化特性,使其消融过程中土壤水分迁移动向发生变化。采用烘干法,对采煤沉陷区不同立地类型冻结滞水消融过程中的土壤含水率进行了测定。结果表明:(1)随着融化时间的延长,采煤沉陷区阴坡土壤含水率峰值沿着垂直方向逐渐向下推移。冻结滞水融化第2天和第5天,土壤含水率峰值出现在0~10 cm土层;融化第8天土壤含水率最大值出现在20~30 cm土层;融化第11、14和17天土壤含水率最大值均出现在50~60 cm土层;(2)采煤沉陷区沟坡地冻结滞水融化第2天和第5天土壤含水率峰值均出现在20~30 cm土层;融化第8、11、14和17天土壤含水率最大值均出现在30~40 cm土层;(3)采煤区和非采煤区的冻结滞水含水率峰值在冻土层之下。     

刺五加在东北黑土区埂带上的生态适应性及水保效益研究

为了解决东北黑土区坡耕地治理中埂带植物品种少、水保效益差的问题,在黑龙江省牡丹江修建梯田埂和地埂试验区,在埂带上栽植长梗刺五加和短梗刺五加,设置径流小区,以自然裸露为对照。通过对埂带刺五加生物量、泥沙和径流量、对土壤含水量影响及经济效益观测,研究刺五加在东北黑土区埂带上的生态适应性及水土保持效益。结果表明:长梗刺五加和短梗刺五加在梯田埂和地埂上均有良好的适应性;埂带刺五加试验区土壤侵蚀量低于东北黑土区容许土壤流失量200 t/（km²·a）,满足水土保持功能要求;观测不同深度土壤含水量,刺五加埂带显著高于对照;栽植第三年的经济效益,梯田埂上短梗刺五加和长梗刺五加分别达到了96 880元/hm²和10 740元/hm²。地埂上短梗刺五加和长梗刺五加分别达到47 700元/hm²和10 665元/hm²,经济效益显著;二者相比,短梗刺五加在埂带上优于长梗刺五加。     

Stem-specific cadmium accumulation in cadmium-tolerant Polygonum thunbergii

Polygonum thunbergii was selected among wild plants as a cadmium (Cd)-tolerant plant because of the high accumulation of Cd in the stems. However, the concentration of Cd in the leaves was low, which suggested the existence of an inhibitory mechanism of Cd translocation from stems to leaves. Observation of Cd distribution in stem-petiole-lamina in P. thunbergii plants that had absorbed Cd, using SEM-EPMA, revealed that Cd accumulation occurred mainly in the nodes, junctions of petioles, and vessels in stems, with minimal translocation in petioles. A detection method for tissue distribution of Cd was developed. Resin-fixed tissue tips were stained with a fluorescent probe BTC-5N and then sites of Cd location were detected with a fluorescence microscope. It was found that Cd in the stem tissues of P. thunbergii was distributed at specific sites of the cell walls of vessels and surrounding cells. The results were consistent with the findings of the investigation of Cd distribution in stem cells obtained by the cell fractionation method, which showed that most of Cd was present in the cell wall and cytoplasm. These results suggest that P. thunbergii accumulates Cd in specific cell walls of the stems and inhibits Cd-translocation to the leaves.     

Effects of Soil Alkalization on Osmotic Adjustment and Ion Balance in Sorghum (Sorghum Bicolor L.)

Sorghum (Sorghum bicolor L.) was grown on an alkalinized plot for 90 days. Inorganic ions and compatible solutes were measured to investigate the physiological adaptations by which sorghum tolerates natural alkaline stress. Plant growth was clearly inhibited. The stress led to increased Na⁺ content in roots but had only a small effect on Na⁺ accumulation in leaves; K⁺ content in roots was lower than that in leaves and stems; and Na⁺ content and Na⁺/K⁺ ratio were much higher in roots than in leaves and stems. These suggest that maintaining a substantially higher osmotic potential in roots for greater uptake of water and restricting the spread of Na⁺ to shoots are physiological adaptations to alkalinity. Soluble sugar was the main osmolyte in roots, stems, and leaves; proline, amino acids, and oxalates contributed to osmotic regulation slightly, and it was noteworthy that K⁺ played a major role in osmotic regulation in leaves.