典型植物叶表面非光滑形态的疏水防黏效应

用扫描电镜技术对几种典型植物叶片进行电镜扫描,对其不同的非光滑表面特征类型分类并加以描述;借助于仪器设备对非光滑叶表面的疏水性与防黏性进行量化指标的测定,分析结果表明：表皮细胞形态、表面蜡层形态与分布密度将直接影响其疏水、防黏效果;并进一步指出表皮细胞形态及其分布密度是表面脱附的主导因子,表皮蜡质因其形态、分布密度不同脱附效果也有差别。该研究将为工程仿生的表面加工成型、表观设计提供重要的信息源。     

典型状态下荷叶润湿性差异及其机理分析

为了研究荷叶不同状态下润湿性差异的成因与机理,通过对荷叶在鲜、老、病、枯4个典型状态下进行润湿性观察、与水接触角测量、扫描电镜观测,分析其表面微观形貌、化学蜡质含量等要素的变化规律,揭示润湿性差异的成因与机理。结果表明:鲜叶为微米级乳突和纳米级蜡质层覆盖的二元复合微观形貌,枯叶乳突和蜡质层稍有萎缩,但微观结构变化不显著;老叶微观形貌中出现了少许"板条"状突起和乳突、蜡质层共同构成其粗糙叶表结构;而病叶"乳突+蜡质层"的二元复合结构发生明显变化,呈现无序的线型纤维柱状网络结构。不同状态荷叶表面与水接触角测量结果显示,鲜、老、枯叶仍呈现疏水或超疏水状态,而病叶呈现亲水状态,润湿性能发生根本改变。荷叶表面蜡质含量在不同状态下也存在一定差异,老叶、枯叶蜡质含量与鲜叶接近,但疏水性皆低于鲜叶。研究表明荷叶不同状态下润湿性差异的成因在于其叶表微观形貌和化学蜡质含量发生改变造成的,从这2个因素对其疏水性的贡献率来比较,叶表微观形貌是决定其疏水程度的主因。研究结果为疏水表面仿生设计提供参考。     

典型土壤动物体表形态减粘脱土的初步研究

土壤动物的不粘土特性,对于地面机械减粘脱土的仿生研究具有重要意义。本文利用实体显微镜和扫描电镜对典型土壤动物穿山甲、蝼蛄、蚂蚁和蜣螂等的体表形态进行了观察研究。结果表明,上述土壤动物具有类似波纹状的体表结构,并用波形表面模型进行了减粘脱土的机理分析。     

土壤粘附仿生研究(二) 典型土壤动物体表形态减粘脱土的初步研究

土壤动物的不粘土特性,对于地面机械减粘脱土的仿生研究具有重要意义。本文利用实体显微镜和扫描电镜对典型土壤动物穿山甲、蝼蛄、蚂蚁和蜣螂等的体表形态进行了观察研究。结果表明,上述土壤动物具有类似波纹状的体表结构,并用波形表面模型进行了减粘脱土的机理分析。     

珠江三角洲地区土壤与表层沉积物有机质的性质结构研究

通过分析海洋、河流、池塘和稻田四种热带 /亚热带土壤与表层沉积物及用化学方法分离的有机质 ,证明了土壤与沉积物有机质是高度不均匀的 ,除了包括腐殖酸和演化程度较深的干酪根外 ,强调了演化程度更深的碳黑的存在 ,并对不同有机质的来源、性质和结构进行了表征。腐殖酸和干酪根来源于生物体的演化 ,在结构上后者比前者致密 ;碳黑来源于化石燃料和生物体的不完全燃烧 ,具有更致密的结构 ,对有机质的非均质性影响很大。因此可认为 ,系统地研究土壤与表层沉积物有机质的非均质性及组分特征对了解地球表层的生物地球化学过程和疏水性毒害有机污染物在环境中的迁移具有重要的意义。     

裸脚菇0612-9提取物对柑橘青、绿霉的抑菌活性及作用机制

为探索裸脚菇0612-9提取物(GSFE)对意大利青霉(Penicillium italicum)和指状青霉(P. digitatum)的抑菌活性和作用机理,本试验采用菌丝生长速率法测定GSFE对意大利青霉和指状青霉的抑菌活性,分析GSFE处理后意大利青霉和指状青霉的菌丝形态、细胞膜通透性和麦角固醇含量变化情况,并通过靶位竞争剂试验探究GSFE的抑菌机理。结果表明,GSFE对意大利青霉和指状青霉的半有效浓度(EC₅₀)值分别为116.76和147.74 μg·mL^-1,最小抑菌浓度(MIC)均为200 μg·mL^-1;经质量浓度为EC₅₀和MIC的GSFE处理后意大利青霉和指状青霉菌丝体均发生严重的皱缩、干瘪,并且胞内呈空泡状结构,细胞质大量减少,胞外相对电导率显著上升,菌体内核酸、可溶性蛋白等胞内物质含量显著降低。这表明意大利青霉和指状青霉细胞膜通透性增加,胞内物质外泄,细胞膜完整性遭到破坏。经浓度为EC₅₀的GSFE处理的意大利青霉和指状青霉菌丝体,其麦角固醇含量均显著降低,分别仅为对照组的17.92%和20.13%。由此可见,GSFE主要通过抑制意大利青霉和指状青霉菌丝体的麦角固醇合成而损伤病原真菌细胞膜的结构和功能。本研究结果为后续开发新型微生物源柑橘采后保鲜剂提供了设计思路。     

日光温室PE发泡自防水保温被的研制与性能测试

研制、开发具有性能良好、使用寿命长的保温被是设施园艺市场的迫切需求。草苫虽然保温性好、价格低廉,但它具有笨重、吸水、污损薄膜、易腐烂等缺点。该文介绍了一种采用以PE闭孔发泡自防水材料为芯、涤纶布为面的保温材料和双面整体粘合技术研制的具有良好的防水性、保温性、使用寿命长的保温被。通过实验和仪器检测表明：该保温被具有良好的防水性、保温性且强度高。与传统保温被相比,除具有保温、质轻、耐腐蚀等特性外,性价比高,防水性和抗老化性能尤为突出。     

几种日光温室复合保温被保温性能分析

通过试验测定,分析了目前市场上最新推广的６种日光温室前屋面保温被的保温特性。试验采用单拱棚。测试结果表明被测６种保温被中的５种其保温能力达到或超过了单层稻草草苫的保温水平,文中还对保温被的结构和防水性能进行了讨论,对其中反光铝箔层设置的必要性进行了分析,对保温被结构及其保温性能的进一步改进和提高提出了措施。     

元谋干热河谷冲沟形态特征及其成因

元谋干热河谷冲沟极为发育,发达的冲沟网络不但蚕食耕地,还产生大量泥沙,并加剧面蚀的发育发展,加速土地退化进程.在干热河谷开展冲沟侵蚀研究对于该区经济的可持续发展及江河泥沙的控制意义深远.采用野外实地调查、文献资料综合分析的方法,对元谋干热河谷冲沟形态特征及其成因进行了研究.结果表明:1)元谋干热河谷冲沟具有“沟壁陡立、沟谷深壑、活跃沟头常呈上凸下凹状”等形态特征;2)岩层结构、气候降雨、土壤属性是导致该区冲沟发育的主要原因.在此基础上指出,未来干热河谷冲沟侵蚀研究重点应集中于冲沟形态监测方法、冲沟发育过程及机制、冲沟产沙效应及人类活动对冲沟发育的影响等方面.     

四种昆虫鞘翅断面的超微观结构及仿生模型（英）

研究动物鞘翅的内部结构,为复合材料的结构设计提供设计依据,以东方白点花金龟（Protaetia orentalis）、臭蜣螂（Copris ochus）、星天牛（Anoplophora chinensis）和黄缘真龙虱（Cytister bengalensis）为研究对象,利用扫描电子显微镜对鞘翅断面进行了分析,并结合四种昆虫的生活环境,对观察到的鞘翅材料结构进行了分析和总结;针对鞘翅材料的结构特点,概括和总结了纤维模型和层状复合材料模型。研究结果表明：四种昆虫的鞘翅均由层状复合材料组成,在鞘翅内部发现的纤维（束）的形态略有区别。在花金龟鞘翅的纤维（束）形态有T型结构、正交叠层结构和分叉纤维结构;臭蜣螂鞘翅的纤维（束）形态有网状结构、块状凸起结构和刺状纤维结构;星天牛鞘翅的纤维（束）形态有空腔结构、螺旋结构、孔洞结构和刺状结构;龙虱鞘翅的纤维（束）形态有空腔和孔洞结构。这些天然生物纤维结构形式为轻质仿生复合材料的结构设计提供了可供学习和效仿的生物模型;基于四种昆虫鞘翅的内部结构分析,总结了常用的几种纤维模型,即分叉纤维模型和螺旋纤维模型,并对两种模型进行了模型示意,几种结构模型为复合材料特别是层状复合材料和纤维增强复合材料的仿生结构设计提供了依据。     

Root hairs and the acquisition of plant nutrients from soil

The literature on the role of root hairs when plants acquire mineral nutrients from soil is reviewed. After a short outline of the root properties affecting the acquisition of nutrients, the roles of root hairs are discussed in four sections, entitled: morphological properties of root hairs, mode of action of root hairs, factors affecting the formation of root hairs, and relationship between root hair formation and plant nutrient uptake. The formation of root hairs depends on both genetic and environmental factors, particularly the supply of phosphate and nitrate. It is concluded that root hairs may substantially contribute to the acquisition of nutrients, mainly those of low mobility in soil and high demand in plants. The percentage of a nutrient acquired by root hairs varies widely, from almost zero to approximately 80 % of the total uptake of the nutrient. The contribution of root hairs depends on plant species and the genetic variability of root hair formation on the one hand, and the kind of nutrient and its availability in soil on the other. According to the published reports, essentially only phosphorus and potassium were considered.     

热胁迫下羽叶薰衣草植物腺毛发育的超微结构

本研究利用透射电子显微镜观察热胁迫下羽叶薰衣草腺毛超微结构变化,结果表明：40℃热胁48h后,腺毛细胞中参与合成与分泌的主要细胞器受到严重破坏。质体变形,缺少基质和嗜锇物质;线粒体缺少嵴,液泡化严重;小泡不正常地融合在一起,并靠细胞壁分布;内质网呈链条状,片层似球形,核糖体显著地附在内质网片层上;细胞核出现大量的纤维状颗粒物质;分泌时期的质膜和细胞器膜等扭曲变形。说明热胁迫影响腺毛的发育与精油的分泌,从而进一步影响精油的产量和质量。     

不同照明条件下菌菇罐头中发丝的准确识别

为了实现菌菇罐头工业化生产过程中发丝异物的自动识别,该文提出了一种基于发丝中轴特征的图像识别方法。由于菌菇罐头中含水且表面不平整,不同照明条件对发丝识别效果有较大影响。因为普通照明条件下反光与阴影干扰远多于理想照明条件下反光与阴影干扰,所以普通照明条件下菌菇罐头中发丝的识别难度更大。该文用带Gaussian滤波的Hessian矩阵法提取发丝中轴特征,通过取阈值、非局部极大值抑制、8邻域连接得到中轴线,结合平行边缘特征,剔除残留的菌菇阴影中轴线,识别出发丝中轴线。试验结果表明:普通照明条件下,该方法的识别性能远好于平行边缘法、正交旋转滤波器法、四阶优化旋转滤波器法和Gaussian核平移线性组合法;对2种照明条件下采集的常见发丝(含黑色、直径70μm)的原始图片和特种发丝(含黄色、直径50μm)的原始图片,该方法都能够准确识别出发丝;尤其对较难识别的普通照明条件下复杂形状的常见发丝和特种发丝,该方法识别结果的准确率分别是0.98637和0.97007。该方法可用于菌菇罐头生产企业的发丝图像识别。     

Root trait plasticity and plant nutrient acquisition in phosphorus limited soil

To overcome soil nutrient limitation, many plants have developed complex nutrient acquisition strategies including altering root morphology, root hair formation or colonization by arbuscular mycorrhizal fungi (AMF). The interactions of these strategies and their plasticity are, however, affected by soil nutrient status throughout plant growth. Such plasticity is decisive for plant phosphorus (P) acquisition in P‐limited soils. We investigated the P acquisition strategies and their plasticity of two maize genotypes characterized by the presence or absence of root hairs. We hypothesized that in the absence of root hairs plant growth is facilitated by traits with complementary functions, e.g., by higher root mycorrhizal colonization. This dependence on complementary traits will decrease in P fertilized soils. At early growth stages, root hairs are of little benefit for nutrient uptake. Regardless of the presence or absence of root hairs, plants produced average root biomass of 0.14 g per plant and exhibited 23% root mycorrhizal colonization. At later growth stages of maize, contrasting mechanisms with functional complementarity explained similar plant biomass production under P limitation: the presence of root hairs versus higher root mycorrhizal colonization (67%) favored by increased fine root diameter in absence of root hairs. P fertilization decreased the dependence of plant on specific root traits for nutrient acquisition. Through root trait plasticity, plants can minimize trade‐offs for developing and maintaining functional traits, while increasing the benefit in terms of nutrient acquisition and plant growth. The present study highlights the plasticity of functional root traits for efficient nutrient acquisition strategies in agricultural systems with low nutrient availability.     

The role of ethylene in root hair growth in Arabidopsis

Ethylene promotes root hair development in many higher plants. Recently the role of ethylene has been investigated in Arabidopsis because of the range of genetic resources available in this species. Root hairs in the Arabidopsis root form on specialized epidermal cells (trichoblasts) located in the cleft between underlying cortical cells. Hairless epidermal cells develop from atrichoblasts that are located over single cortical cells. Ethylene not only promotes root hair outgrowth but also causes cells that are normally hairless to form root hairs. This suggests that ethylene may play a dual function in the formation of root hairs. Firstly it may play a role in hair initiation and secondly may be required for the elongation of hairs. Alternatively it may suggest that these are two parts of the same process.     

干旱胁迫下不同茸毛性状辣椒植株抗旱性比较

干制辣椒种子经60Coγ射线辐照后种植,获得一株茸毛变异株。以多年自交的多茸毛系及其姊妹系无茸毛系和少茸毛系为试验材料,研究干旱胁迫条件下辣椒体表不同茸毛状态与抗旱性的关系。结果表明:在干旱胁迫下多茸毛系植株抗萎蔫的能力显著优于无茸毛系和少茸毛系;干旱胁迫前期主要表现为抑制植株生长,多茸毛系的株高,茎粗和节间数分别比对照降低3.38%,7.25%和2.7%,降低幅度显著低于其他系;持续到结果期,多茸毛系的抗旱能力优势表现在产量降低量较少,为22.94%,而无茸毛系降低69.91%,少茸毛系降低42.94%,表明辣椒体表茸毛性状在干旱胁迫下能有效降低辣椒经济产量的损失率,耐旱能力与茸毛多少有关。     

Adaptive Phenotypic Differences to Low Potassium Soil of Two Cotton Genotypes with Various Potassium-Use Efficiencies

Cotton (Gossypium hirsutum L.) is one of the most important cash crops in the world, and potassium (K) is an important limiting factor for cotton farming. Therefore, it is critical to improve K-use efficiency by selecting or breeding cotton genotypes with high K-use efficiency. Through a pot experiment with low-K soil, this article documentes the differences in vessel element anatomy and root hair traits between two cotton genotypes with different K-use efficiencies at both seedling and boll stages. Experimental results showed that at the seedling stage both frequency and length of root hair in the genotype with high K-use efficiency were significantly greater than those of the genotype with low K-use efficiency, but the frequency and diameter of vessels were not significantly different between the two genotypes. In the boll stage, the vessel frequencies in root, stem, petiole, and carpophore; root hair frequency, and length of high K-use-efficiency genotype were all significantly greater than those of the low K-use-efficiency genotype. The denser and longer root hairs were often found and accompanied by thicker vessel elements in the genotype with high K-use efficiency. This means the genotype had greater nutrient uptake and transportation capacity. The root hairs, vessel elements in root, stem, petiole, and carpophore, formed a complete system for nutrient uptake and translocation. The results from this study provide valuable information for the breeding of high K-use-efficiency cotton.     

Extraction of light filth from coconut: collaborative study

The official method for filth in coconut, 44.029, frequently produces filter papers with excessive plant debris and low hair recoveries. To overcome these deficiencies, 3 changes in the method were made: (1) the defatting step was modified to use sodium lauryl sulfate in combination with borax for better defatting; (2) 40% isopropanol was substituted for 60% ethanol as the aqueous phase for cleaner papers; and (3) mineral oil was substituted for n-heptane to improve hair recoveries. These changes resulted in higher, more reproducible recoveries of rodent hairs and insect fragments and cleaner filter papers. The method has been adopted as official first action to replace 44.029.     

Low-P solution culture can be used for screening root growth vigor in soil for high nutrient uptake of spring wheat varieties

Purpose: Root and root hairs of plants have been intensively studied in solution culture; however, correlation of such measurements in solution culture with development in soil is poorly understood. Therefore, the aim of this study is to study whether root and root hairs grown in solution culture can predict their behavior in soil and their correlation with macro- and micronutrients uptake of wheat genotypes.

Materials and methods: The growth of roots and root hairs as well as uptake of macro- and micronutrients of six spring wheat varieties was compared in solution culture under P stress and P abundance and in a low fertility soil.

Results and conclusions: Root length and surface area under P stress were significantly positively correlated with that in the low fertility soil, while no such correlation was apparent for root hair length and density. In absolute terms, the root length, surface area, root hair length and density of spring wheat varieties were substantially higher in soil than in solution culture, while the concentration and uptake of macro- and micronutrients in soil differed from solution culture in a complex way. The early uptake of macro- and micronutrients was intimately associated with root length and surface area as well as root hair length and density in soil but not in solution culture. Therefore, root length rather than root hair traits in low-P solution may be used to screen early root growth vigor in soil and thereby high nutrient uptake of wheat in low fertility soil.