植物叶片表面特征对美洲斑潜蝇的抗性观察

通过对美洲斑潜蝇生物学特征和植物叶片表面特征初步观察，研究，发现植物叶片表面特征不同，对美洲斑潜蝇抗性存在差异。     

干旱胁迫对3种苹果属植物叶片解剖结构、微形态特征及叶绿体超微结构的影响

采用树脂包埋块半薄/超薄切片技术，通过光镜（LM）、扫描电镜（SEM）和透射电镜（TEM）方法，研究了轻度、中度和严重干旱胁迫对楸子（Malus prunifolia）、新疆野苹果（M. sieversii）和平邑甜茶（M. hupehensis）叶片组织解剖结构、表皮微形态特征（气孔密度、大小及角质层厚度）及叶绿体超微结构的影响。光镜观察结果表明，与对照相比，干旱胁迫条件下3种苹果属植物叶片厚度、栅栏组织厚度及叶肉组织结构紧密度（CTR）都显著减小（P＜0.05），而海绵组织厚度与叶肉组织结构疏松度（SR）均显著增加（P＜0.05）。扫描电镜观察结果显示，3种苹果属植物幼叶气孔密度在干旱胁迫下显著增大（P＜0.05），而气孔宽度、开张比及其开张度明显下降。透射电镜观察结果表明，在干旱胁迫下，楸子和新疆野苹果上下角质层厚度逐渐增加，而平邑甜茶的随干旱胁迫程度增加呈先增后减的变化；在轻度和中度水分胁迫下，叶绿体膨胀变形，淀粉粒变小消失，基粒片层排列松散减少，类囊体腔扩大；在严重胁迫条件下，叶绿体膨胀近圆形，叶绿体膜破裂，类囊体严重泡化开始解体。与平邑甜茶相比，严重水分胁迫下楸子和新疆野苹果叶绿体超微结构损伤较小，能较好地保持细胞结构的完整性。     

新疆猪毛菜属17种C_4植物叶片和子叶的解剖结构研究

通过对藜科猪毛菜属17种C4植物的叶片和子叶的解剖学研究,共得到2种叶片的解剖结构类型,Salsoloid具有皮下组织型(SALS+H型)和Salsoloid不具有皮下组织型(SALS-H型);4种子叶的解剖结构类型分别是C3-异面叶型(C3-DV型)、Atriplicoid且具有皮下组织型(ATR+H型)、SALS+H型和SALS-H型。同一种植物子叶和叶片的解剖结构类型并不完全一致,分为2大类。一类是子叶和叶片都是C4型解剖结构,包括叶片SALS+H型/子叶ATR+H型、叶片SALS+H型/子叶SALS+H型和叶片SALS-H型/子叶SALS-H型;另一类是叶片具有C4型解剖结构,子叶具有C3型解剖结构,包括叶片SALS+H型/子叶C3-DV型和叶片SALS-H型/子叶C3-DV型。同组植物子叶和叶片的解剖结构类型具有一定的规律性,不同组之间植物光合器官的解剖结构类型存在较大的差异,这些差异性与植物生活型、地理分布没有关系。     

水分胁迫下云杉属两种植物荧光参数特征研究

以青海云杉(Picea crassifolia)和沙地云杉(Picea mongolica)为试验材料,测定了正常供水条件、中度土壤水分胁迫、重度土壤水分胁迫条件下两树种的叶绿素荧光参数。结果表明:随着干旱胁迫的加剧,云杉属两种植物的实际量子效率(ФPSII)呈递减趋势;初始荧光(Fo)呈递减趋势;两种云杉的最大光化学量子产量(Fv/Fm)均集中在0.7左右,而且随着土壤水分的减少,最大光化学量子产量呈下降趋势;光化学猝灭系数(q P)呈递减趋势,非光化学淬灭系数(q N)随着土壤水分的减少呈递增趋势;PSⅡ实际光化学效率(Yield)与电子传递速率ETR表现出相似的规律性,均呈下降趋势。综合分析各项指标表明沙地云杉具有更强的抗旱性。     

柽柳属植物的分类特征

本文系统地讨论了柽柳属植物的花序和开花习性,花盘的构型,苞片、花萼、花冠脱落与否和曲率,雄蕊、雌蕊、果实、枝干以及叶子等形态特征,评价了它们的分类特征,为鉴定本属植物提供了正确的分类依据。     

中美植物有害生物风险分析体系研究比较

美国是植物有害生物风险分析研究领先的国家之一,我国的有害生物风险分析研究工作也已走过近20年的历程.本文从法律法规、组织机构和人力资源、工作程序和技术体系、应用功能等4方面对中美两国的植物有害生物风险分析体系进行全面研究和比较,以期借鉴美国的一些先进经验,不断完善我国的风险分析体系.     

两种生境条件下空心莲子草叶片解剖结构比较

通过扫描电子显微镜和光学显微镜的观察比较，发现空心莲子草在水生和旱生两种生境下叶片组织的形态结构有较大的差异，这说明空心莲子草具有在不同的生境中组织形态结构会发生相应变化的特点，这可能是空心莲子草能在不同生境条件下迅速扩散的原因之一。     

中国沙穗属植物研究

沙穗属(Eremostachys)是本格(Bunge)建立的一个属,于1830年在《Ledeb.F_1alt.》中以E.molucceolloides Bunge等为模式种首次发表了9种沙穗,其后由俄国学者M·Popov经广泛而深入的研究于1840年在《Nouv.Mem.Soc.Nat.Moscow.》第十九卷中发表了约20种沙穗,随后相继有许多植物学家对全世界沙穗属植物进行全面而系统的研究,发表了许多新的种群,其中较著名的学者有瑞格尔(Regel)。他于1879年在《Act.Hort.Petrop.》第六卷中发表了约15种沙穗。     

4种薰衣草属植物抗旱性综合评价

采用负水头供水控水装置控制盆土体积含水量,对轻度、中度和重度干旱胁迫0、10、20、30 d和40 d后4种薰衣草属植物叶片相对含水量(RWC)、丙二醛(MDA)、可溶性糖(SSC)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT) 5个抗旱生理指标的变化规律开展研究,旨在对其抗旱性进行综合评价。结果表明：随干旱胁迫强度和时间的增加,4种薰衣草的RWC均呈下降趋势,且轻度干旱胁迫的RWC显著高于中度和重度干旱胁迫（P＜0.05）,其中,干旱发生至重度胁迫时,普罗旺斯薰衣草的RWC最高,为56.56%,孟士德薰衣草仅为39.02%;而MDA和SSC则呈上升趋势,且随胁迫程度的增强而增加,其中,胁迫至40 d时,普罗旺斯薰衣草的MDA较0 d（CK）各处理水平增加幅度达118.67%, 而其SSC含量显著高于其它3种薰衣草。4种薰衣草的SOD和CAT活性呈先升后降的变化趋势,均于胁迫至20 d时达到最高值,且轻度干旱胁迫下的SOD和CAT活性高于中度和重度胁迫,其中,孟士德薰衣草的SOD和CAT活性最低。根据模糊数学隶属函数法综合评价分析得出,4种薰衣草抗旱性强弱依次为：狭叶薰衣草＞普罗旺斯薰衣草＞蝴蝶薰衣草＞孟士德薰衣草。     

广西外来入侵生物发生为害特征和扩散机制

总结美洲斑潜蝇等31种广西主要外来入侵物种的特征,分析外来生物传入、定植(殖)、停滞、扩散4个阶段的特点,指出了生物入侵的主要因素是由于入侵种自身强大的繁殖特性、生态适应性和竞争力,传入地适宜的气候和环境条件,缺乏自然控制机制以及人类活动、自然传播能力等。     

定西柠条VA菌根真菌特征及种类研究

对从甘肃定西定安区采集的柠条VA菌根真菌进行分离,共鉴定出8种VA菌根真菌：缩球囊霉（Glomus constrictum Trappe）,地球囊霉（Glomus gepsporum Gerdemann,J．W and J．M．Trappe）,集球囊霉（Glomus fasciculatu Gerd．＆ Trappe emend．Walker ＆ Koske）。两型球囊霉（Glomus dimorphicum Boyetchko ＆ Tewari）。微丛球囊霉（Glomus microaggregatum Koske Gemma ＆ Olexia）,苏格兰球囊霉（Glomus caledonium（Nicol．＆ Gerd．）Gerd．＆ Trappe）,副冠球囊霉（Glomus coronatum Giovannetti）和巨大巨孢囊霉（Gigaspora gigantean Gerd．＆ Trappe）。并对这8种VA菌根真菌的主要形态进行了描述,分析了其侵染情况及结构特征。     

引起葡萄叶斑病的链格孢种类的初步鉴定

为明确北京市大兴区、顺义区和山西省襄汾县葡萄树上叶斑病的病原菌,利用组织分离法对病样进行分离纯化,采用多基因系统发育学分析(ITS,Alt a 1和gpd)和形态学对纯化后菌株进行鉴定,并结合柯赫氏法则对其进行验证。结果表明,共获得37株链格孢属真菌菌株,分属链格孢Alternaria alternata、葡萄链格孢A. viniferae和乔木链格孢A. arborescens,柯赫氏法则检测结果显示接种菌株对所接叶片与果穗均具致病性,说明这3种链格孢种均为葡萄叶斑病的病原菌;葡萄链格孢为主要的病原菌,有28株,故将该类病害命名为葡萄链格孢叶斑病;此外,该类菌株在2～40℃之间均能生长,25℃为最适生长温度。     

Characterization of Alternaria species associated with leaf blight of sunflower in China

Nine Alternaria species have been reported to be associated with sunflower leaf blight worldwide, and A. helianthi has been recognized as the most prevalent and damaging species. However, the population structure of Alternaria species causing leaf blight of sunflower in China had not been examined thoroughly prior to this study. During 2010 to 2013, a total of 272 Alternaria isolates were obtained from infected sunflower leaves in 11 provinces, autonomous regions, and municipalities of China. Based on morphological traits and sequence analyses of the internal transcribed spacer (ITS) regions of ribosomal DNA (rDNA) and the partial coding sequences of the histone 3 gene, 227 (83.5 %) isolates were identified as belonging to Alternaria tenuissima, the remainder 45 isolates were grouped to A. alternata (16.5 %). Compared with the ITS regions of rDNA, sequence analyses of the partial coding sequences of histone 3 gene displayed a critical role in discrimination of the small-spored Alternaria species. Phylogenetic analysis of the partial coding sequence of histone 3 gene clearly divided the representative Alternaria isolates into two main clades, A. tenuissima and A. alternata. The pathogenicity of A. tenuissima and A. alternata on detached leaves of sunflower cv. Gankui No.2 did not significantly differ between the two species or among isolates from different geographical origins. Our results indicate that the population structure of Alternaria species associated with sunflower leaf blight differed from that reported previously in China since A. helianthi was not found in this study. In addition, this is the first report about A. tenuissima causing leaf blight on sunflower in China.     

Association of Pedilanthus leaf curl virus with yellow mottling and leaf curl symptoms in two jasmine species grown in India

Association of Pedilanthus leaf curl virus (PeLCV) with yellow mottling of crape jasmine (Tabernaemontana coronaria) and leaf curl of night blooming jasmine (Cestrum nocturnum) was investigated using a sequence analysis of the cloned full-length genome amplified by Rolling circle amplification using Φ-29 DNA polymerase. In the sequence analysis, virus isolates from T. coronaria (JN807764) and C. nocturnum (JQ012790) shared 95 % sequence identity with each other and the highest identity (93 %) and the closest phylogenetic relationships with PeLCV (AM712436); therefore, the virus isolates were identified as PeLCV strains. This report from India is the first on the occurrence of PeLCV on T. coronaria and C. nocturnum anywhere in the world.     

Variance in leaf spot susceptibility in chestnut trees of different species and hybrids

Journal of Plant Diseases and Protection - Prior to the first occurrence of chestnut blight in 1976, leaf spot caused by Cylindrosporium castaneae was one of the most important diseases of European...     

北京7种经济林吸滞PM_(2.5)特征及其价值评估

文中选取北京7个经济林树种,在仅考虑生态功能前提下,分析其作为园林绿化树种的吸滞PM_(2.5)特征,探讨叶表面形态特征对其影响,并利用合理指标评估其生态价值。结果表明:不同树种吸滞PM_(2.5)量介于0.089~0.258μg·cm-2,排序为:苹果>桃>枣>梨>核桃>杏>樱桃;吸滞PM_(2.5)量均在7、8月份较高,5月份较低;叶表面形态特征复杂,较为粗糙的叶片吸滞PM_(2.5)能力强;苹果吸滞PM_(2.5)量为0.83 kg·hm~(-2)·a-1,价值量约为67.47元·hm~(-2)·a-1。     

Evaluation of Galium species and populations using morphological characters and molecular markers

Three Galium species are believed to be present across western Canada: Galium aparine, Galium spurium and Galium boreale. Galium spurium and G. aparine are very difficult to distinguish morphologically, which is problematic for crop consultants and weed surveyors, and could have implications for control measures. Molecular techniques could potentially make identification easier and more rapid than using chromosome counts, as is currently done. The objective of this study was to identify morphological traits and/or genetic polymorphisms capable of species differentiation. To this end, Galium seed of unknown speciation were collected from nine field populations across western Canada and, along with two reference samples of G. spurium and G. aparine, were characterised for both morphological traits and their ribosomal ITS1‐5.8S‐ITS2 genomic sequence. In addition, single nucleotide polymorphism variation within the highly conserved 5.8S ribosomal RNA gene was identified that could consistently differentiate Galium species. Sequence analysis of the ITS1‐5.8S‐ITS2 region of field collections from western Canada indicated that all samples were G. spurium and all were highly related to each other. These results were supported by a distinct lack of variation in morphological traits, as nearly all plant traits measured did not differ between populations. This suggests that all sampled populations, and perhaps most of the Galium populations across western Canada, are derived from a single species, G. spurium.     

Comparative morphology of Phytophthora species on rubber

Eighty-nine Phytophthora isolates from rubber throughout the world were examined critically. Five species were distinguished: P. palmivora morphological form I (MF1), P. meadii, P. botryosa, P. citricola, P. citrophthora and one currently designated P. palmivora (MF4). P. citrophthora is reported for the first time from rubber in the Ivory Coast and Indonesia, and mating types are given.     

引起云南省珠芽魔芋叶斑病的链格孢菌种类鉴定

珠芽魔芋Amorphophallus bulbifer是我国西南地区广泛种植的一种特色经济作物,自2015年开始云南省德宏州及西双版纳州珠芽魔芋种植区发生了一种魔芋新病害。典型症状为早期叶片上出现具黄色晕圈圆形斑点,逐渐形成大斑块,最终整个叶片枯死。本研究采用温室接种致病性测定、形态及分子鉴定等方法对珠芽魔芋叶斑病病原进行研究。结果表明：从各种植区采集的37份叶部病样中分离得到37个生长较一致的真菌分离物;致病性试验证实,均为珠芽魔芋叶斑病病原菌,显微镜下观察该病原菌具有细极链格孢Alternaria tenuissima的形态特征;将其rDNA-ITS、EF-1ɑ和β-tubulin基因序列在GenBank中进行同源性比对分析显示,其序列与A.tenuissima的相似性为99%～100%,分子鉴定与形态学鉴定结果一致。这是国内首次发现由细极链格孢侵染所引起的珠芽魔芋叶斑病。