Host range of the parasitic weed Osyris alba L. in Jordan

A field survey revealed the presence of Osyris alba L., the root hemi-parasitic weed, with 23 plant species of 14 families found in the central/west parts of the Hashemite Kingdom of Jordan. The host list includes shrubs and fruit and forest trees of high economic value. New hosts were added to the existing list. The most severely attacked fruit trees are Amygdalus communis L., Olea europaea L., and Vitis vinifera L., while the most severely attacked forest trees are Cupressus sempervirens L . , Acacia cyanophylla Lindl. and Rhamnus palaestina Boiss. The distribution and intensity of parasite infection of different hosts were evaluated. This work is the first record of O. alba and its hosts in the Kingdom of Jordan.     

奇台荒漠草地自然保护区典型植物群落物种多样性分析

以重要值为测度指标,选择反映群落物种多样性、丰富度、优势度和均匀度的7个测定指数对奇台荒漠草地自然保护区荒漠植物群落物种多样性进行了研究。结果表明:在整个研究区荒漠植物群落中,白梭梭、梭梭、碱蓬、琵琶柴、沙蓬、驼绒藜和沙漠娟蒿等物种有较高的重要值。依据群落外貌结构和植物种类组成等特征,按照样方中建群种和优势种的重要值,将研究区植物划分为14个典型群落,各群落类型的物种多样性指数(Shannon-wiener指数H′)的顺序为:梭梭+角果藜(2.0740)>白梭梭+驼绒藜(1.9037)>白梭梭+羽毛三芒草(1.8909)>梭梭+芦苇(1.8474)>梭梭+雾冰藜(1.7434)>芦苇+猪毛菜(1.7278)>梭梭+白茎娟蒿(1.6723)>白梭梭+琵琶柴(1.5410)>白梭梭+沙蓬(1.4886)>白梭梭+假木贼(1.4530)>梭梭+碱蓬(1.4437)>白梭梭+刺木蓼(1.4277)>白梭梭+角果藜(1.3637)>白梭梭+沙漠娟蒿(1.3362)。     

艾比湖湿地自然保护区荒漠植物群落物种多样性研究

以重要值为测度指标,选择反映群落物种多样性、丰富度、优势度和均匀度的6个测定指数对艾比湖湿地自然保护区荒漠植物群落物种多样性进行了研究。结果表明:在整个研究区荒漠植物群落中,盐穗木、盐节木、白梭梭、梭梭和盐爪爪等物种有较高的重要值,草本的重要值较低。各群落类型的物种多样性指数的顺序为:白梭梭>胡杨>盐穗木>盐豆木>罗布麻>琵琶柴>花花柴>白刺>柽柳>白麻>芦苇>芨芨草>梭梭>骆驼刺>甘草>盐节木。     

Hosts and symptoms of Plum pox virus: woody species other than fruit and ornamental species of Prunus

The presence of Plum pox virus (PPV) in woody hosts other than in fruit and ornamental Prunus species was evaluated. PPV symptoms, and their variability and intensity, are described in leaves and fruits of Prunus cerasifera , Prunus spinosa , Ligustrum vulgare and Euonymus europaea . Juglans regia is not confirmed as a new host of PPV.     

不同水分条件下两种梭梭蒸腾作用比较

梭梭柴(Haloxylon ammodendron)和白梭梭(H.persicum)是准噶尔盆地分布最广的两种植物。自梭梭主要分布在半固定半流动沙丘顶部,梭梭柴则多分布于丘间平地。对于这两种梭梭蒸腾作用的研究,多集中于梭梭柴。关于白梭梭蒸腾作用的研究国内尚鲜见报道。本文对不同水分条件下生长的两种梭梭的蒸腾作用进行了比较。     

极旱环境中两种梭梭蒸腾的生理生态学特点

白梭梭(Haloxylon persicum)和梭梭(H.ammodendron)是我国干旱荒漠区的优良固沙植物,列入我国第一批保护植物,白梭梭主要分布在新疆北部的古尔班通古特沙漠,梭梭除了分布在新疆外,还分布在青海、甘肃、内蒙古等地,对于它们的生物生态学特性的研究,国内已先后做过不少工作,关于生理方面的研究也有报导。本项工作是从水分生理观点着手,结合     

Co-operational PCR coupled with dot blot hybridization for detection and 16SrX grouping of phytoplasmas

A protocol based on Co-operational PCR has been successfully applied to the detection of phytoplasmas. A triprimer reaction coupled with hybridization using general and specific probes permitted detection of ' Candidatus Phytoplasma mali', ' Ca . Phytoplasma prunorum' and ' Ca . Phytoplasma pyri', and their identification as members of 16S ribosomal quarantine group X. The sensitivity of this method was at least one hundred times greater than conventional PCR and similar to that achieved by nested PCR and real-time PCR. The method was validated by testing field samples collected from Malus , Prunus and Pyrus spp. and Olea europaea and compared with seven phytoplasmas maintained in Catharanthus roseus .     

发酵肥料对沙地水分与植物生长的影响

向沙地加入由牛粪分别与棉秆、玉米秆和麦糠发酵而成的肥料,然后种植梭梭与白梭梭,研究发酵肥料对土壤水分和植物生长的影响。结果表明:仅施加1.6%的发酵肥料,不能明显提高土壤含水率;发酵肥料提高了植物的存活率,梭梭的存活率平均比对照高28.1%,白梭梭平均比对照高3.6%;发酵肥料能提高梭梭、白梭梭株高生长量,梭梭、白梭梭肥料处理的累积株高生长量平均比对照高20.3 cm、18.8 cm,两种植物的月生长量与对照差异达显著或极显著水平(P<0.05,P<0.01);发酵肥料能够明显提高两种植物的单枝生长量,肥料处理的月生长量与对照的差异达显著或极显著水平(P<0.05,P<0.01),两种植物肥料处理的累积单枝生长量平均比对照高30.4 cm、25.0 cm。     

肉苁蓉寄生对寄主梭梭体内主要矿质元素含量的影响

对寄生有肉苁蓉的梭梭(HA)与未寄生肉苁蓉的梭梭(CK)不同生长发育时期体内氮、磷、钾、钠、钙、镁、锰、铁等8种矿质营养元素含量的动态变化进行研究。实验结果表明:HA与CK体内的氮、磷、钾、钙、钠以及微量元素铁、锰的含量变化均无显著差异性,只有镁元素二者间差异显著;对于寄生植物肉苁蓉,其体内大量元素氮显著高于HA和CK,磷显著高于HA,而与CK差异不显著,钾、钠、钙、镁、锰、铁6种元素含量均显著性低于HA和CK,同时研究了肉苁蓉寄生后对梭梭体内矿质营养元素的吸收系数的影响,按吸收系数大小排列为N>P>Na>Mg>Ca>K>Mn>Fe。造成以上结果的原因可能与肉苁蓉属于全寄生性植物有关。     

Viruses and viroids of stone fruits in Jordan

Field surveys were carried out in the main stonefruit-growing areas of Jordan to assess the sanitary status of varietal collections, mother plant blocks and commercial orchards. The presence of virus and virus-like diseases was determined by ELISA, sap transmission to herbaceous hosts, graft transmission to Prunus persica cv. GF 305 and P. serrulata cv. Kwanzan, and molecular hybridization tests. A total of 1312 samples was tested by ELISA (531 peach, 361 plum, 218 apricot, 135 almond and 67 cherry trees). The overall mean level of infection was about 14%, indicating an acceptable sanitary status as a whole, considering that no sanitary selection has ever been carried out in Jordan. The infection level of different species was: peach (18%), cherry (15%), almond (14%), apricot (11%) and plum (10%). The following viruses and viroids were identified: Plum pox potyvirus (PPV), Prunus necrotic ringspot ilarvirus (PNRSV), Prune dwarf ilarvirus (PDV), Apple mosaic ilarvirus (ApMV), Apple chlorotic leaf spot trichovirus (ACLSV), Hop stunt viroid (HSVd) and Peach latent mosaic viroid (PLMVd). Most of these agents (ApMV, ACLSV, PLMVd and HSVd) are reported for the first time from Jordan.     

奇台荒漠草地自然保护区主要植物种生态位特征研究

采用Levins公式和王刚生态位计测方法,分析了奇台荒漠草地自然保护区16种植物在土壤pH值,土壤总盐含量和土壤有机质维上的生态位宽度和生态位重叠.结果表明,按照各资源维上生态位宽度的平均值大小可以把16种植物分成3类,第一类群的物种是该荒漠区植物群落中的建群种,对荒漠环境有很好的适应性,包括白梭梭(0.421)、沙拐枣(0.458)、角果藜(0.641)、琵琶柴(0.569)等;第二类群的物种对环境的适应能力较弱,物种有沙蓬(0.326)、对节刺(0.304)、旱麦草(0.221);第三类群的对沙漠的适应能力较弱,生态位平均值均小于0.2,包括盐穗木、梭梭、猪毛菜、假木贼和驼绒藜。优势种的生态位宽度越大相应的生态位重叠值也越大,存在一定的线性关系,表明优势种在对荒漠的环境适应上都趋于相似性。     

阜康北部梭梭荒漠早春物种多样性研究

通过对梭梭荒漠2种植物群落早春的物种组成、垂直结构及物种多样性的对比研究发现:梭梭(Haloxylon ammodendron)群落和白梭梭(Haloxylon persicum)群落具有结构简单、群落优势度高、均匀度和物种多样性较低、旱生性植物占绝对优势及短生植物成为群落重要组成部分等特征。同时,二者存在以下差异:①物种多样性差异, Shannon-Wiener多样性指数、均匀度指数及优势度指数梭梭群落(0.74,0.08和0.81)均高于白梭梭群落(0.61, 0.06和0.77);②主要伴生种不同,前者以草本植物为主要伴生种,后者以灌木为主要伴生种;③短生物种丰富度差异分别占前者的64.7%(11种)及后者的60%(15种)。2种梭梭群落的特点与差异可能与古尔班通古特沙漠南缘早春适宜的水热配置、群落生境的沙土含水量、沙面稳定程度及物种本身的生物学特性等因素有关。     

What makes Haloxylon persicum grow on sand dunes while H. ammodendron grow on interdune lowlands： a proof from reciprocal transplant experiments

Determining the mechanisms underlying the spatial distribution of plant species is one of the central themes in biogeography and ecology. However, we are still far from gaining a full understanding of the autecological processes needed to unravel species distribution patterns. In the current study, by comparing seedling recruitment, seedling morphological performance and biomass allocation of two Haloxylon species, we try to identify the causes of the dune/interdune distribution pattern of these two species. Our results show the soil on the dune had less nutrients but was less saline than that of the interdune; with prolonged summer drought, soil water availability was lower on the dune than on the interdune. Both species had higher densities of seedlings at every stage of recruitment in their native habitat than the adjacent habitat. The contrasting different adaptation to nutrients, salinity and soil water conditions in the seedling recruitment stage strongly determined the distribution patterns of the two species on the dune/interdune. Haloxylon persicum on the dunes had lower total dry biomass, shoot and root dry biomass, but allocated a higher percentage of its biomass to roots and possessed a higher specific root length and specific root area by phenotypic traits specialization than that of Haloxylon ammodendron on the interdune. All of these allowed H. persicum to be more adapted to water stress and nutrient shortage. The differences in morphology and allocation facilitated the ability of these two species to persist in their own environments.     

In vitro culture of Orobanche ramosa

Orobanche spp. (broomrapes) are holoparasites that subsist on the roots of many important crops and can considerably reduce yield. The control of Orobanche spp. includes physical, chemical and biological methods. Interactions between parasitic angiosperms and their hosts first occur at the level of parasite seed germination. The seeds of all Orobanchaceae germinate in soil under natural conditions only in response to specific chemical exudates from the host plant. This study describes the influence of different plant growth regulators and host plant root exudates on germination and development of calli from Orobanche seeds in vitro . The effect of indole-3-acetic acid, gibberellic acid and kinetin on the germination of Orobanche seeds varied with concentration. These plant growth regulators also affected the period of germination and the structure of calli and protrusions. An in vitro system for the collection of tobacco root exudates was established. Compounds released from the host roots of three different tobacco cultivars were found to provoke high levels of germination of the Orobanche seeds without any period of pre-conditioning. This study developed methods for the investigation of host–parasite interactions and the effect of germination stimulants in Orobanche spp.     

NaCl对囊果碱蓬、梭梭和白梭梭种子及初期幼苗的影响

种子萌发和幼苗阶段是干旱区植物群落建成的关键。试验表明,在700 mmoL/L NaCl处理时,与盐生植物梭梭和囊果碱蓬相比,旱生植物白梭梭种子胚中的K~+含量比对照显著降低。700 mmol/LNaCl处理5 d后,白梭梭、梭梭和囊果碱蓬胚中K~+/Na~+分别是对照的33%,27%和74%。高盐处理显著降低3种植物尤其是白梭梭初期幼苗体内K~+含量以及K~+/Na~+。低盐处理下,囊果碱蓬初期幼苗的生长速率明显高于白梭梭和梭梭;高盐处理对3种植物初期幼苗的生长都具有明显的抑制作用。     

Comparative proteomic analysis of Orobanche and Phelipanche species inferred from seed proteins

Orobanche and Phelipanche species are root parasitic plants some of which infect important crops, causing extensive damage. In an attempt to unravel molecular systematic in these genera using protein markers, we established the protein profile of twelve species by two-dimensional gel electrophoresis (2-DE). Proteins were detected by Sypro Ruby staining and the gel images were digitalised and analysed. The 2-DE maps contained from 30 to 140 protein spots for the analysed species. A virtual master gel was built with spots present in all species and revealing the presence of 260 protein spots. Only one protein was monomorphic, while 143 were unique to a single species. Proteins were scored for the presence or absence of homologous spots to create a binary matrix. Phylogenetic analysis was carried out using maximum parsimony and distance method. The trees obtained were rooted using Cistanche phelypaea as an out-group. Both analyses showed Orobanche as a monophyletic group. AMOVA analysis revealed phenotypic diversity between species within genera, as well as a considerable level of variation between genera. This is a first step to help in the phylogenetic classification of parasitic plants by means of proteomics.     

Revisiting strategies for reducing the seedbank of Orobanche and Phelipanche spp.

Weedy Orobanche and Phelipanche species are important in Southern and Eastern Europe, the Middle East and North Africa, and have recently been reported in the USA, Australia and some countries in South America. Rather than being controlled, the Orobanche and Phelipanche problem is increasing, both in intensity and in acreage. Large areas of new territory are at risk of invasion, if care is not immediately taken to limit the introduction of parasitic seeds and to educate farmers and others to be alert for new infestations. There is an urgent need to re-evaluate novel integrated Orobanche and Phelipanche management programmes that will allow a better control of the parasite species and limit their distribution. The main obstacle in the long-term management of Orobanche and Phelipanche infested fields is the durable seedbank, which may remain viable for decades in the field. Large quantities of long-lived seeds give the parasite genetic adaptability to changes in host resistance and cultural practices. As long as the seedbank is not controlled, the need to control the parasite will persist whenever a susceptible host is grown in the infested field. We discuss strategies for seedbank reduction, paying particular attention to cultural practices, whereas chemical and biological control methods are covered by other reviews in this issue.     

软腐欧氏杆菌产细菌素菌株的筛选和细菌素类型的研究

采用Echandi方法,测定了从国内不同植物上分离,经鉴定的3个种和亚种的软腐欧氏杆菌(Erwiniacarotovora var.carotovora Dye,E.carotovora var.otroseptica Dye,E.chrysanthemi Burkholder.etal.)的224个菌株产生细菌素的能力。指示菌为代表3个不同种的菌株。测定结果表明:224个试验菌株中能产细菌素的有97个,占总数的43.3％。经测定产生细菌素的专化性有所不同,约各有1/3菌株分别对3种、2种、1种指示菌有抑制作用。有些广谱的细菌素甚至对其它属的植物病原细菌也有抑制作用。少数种内专化的产细菌素菌株可望用于软腐欧氏杆菌种鉴定的辅助手段。电镜观察初步表明,这些细菌素可能是分子大小不同的两种类型的细菌素:小分子细菌素在电镜下不可见,大分子细菌素具有短杆状结构,颇似无头壳的噬菌体的尾部。     

Parasitic flowering plants of woody species in Jordan

Parasitic weed occurrence in Jordan was surveyed during the period from 2004 to 2009. Results revealed the presence of seven genera attacking 85 woody plant species belong to 33 botanical families. Parasitic genera were Cuscuta, Orobanche, Cistanche, Plicosepalus, Viscum, Osyris and Cynomorium. Among the most severely parasitized species were Citrus spp., Olea europaea, Vitis vinifera, and Ziziphus spina-christi by Cuscuta monogyna; Amygdalus communis and O. europaea by Orobanche cernua, Orobanche palaestina and Orobanche schultzii,; A. communis, Cupressus sempervirens, O. europaea and V. vinifera by Osyris alba; Casuarina equisetifolia and Haloxylon persicum by Cistanche spp.; Acacia asak, Acacia cyanophylla, Acacia farnesiana, Acacia nilotica, C. equisetifolia, Ficus carica, Melia azedarach, Parkinsonia aculeata, Poinciana gilliesii, Retama raetam, Tamarix pentandra and Ziziphus spp. by Plicosepalus acaciae; A. communis, Crataegus azarolus, O. europaea, P. granatum, R. raetam, and Rhamnus palaestina by Viscum cruciatum; and H. persicum by Cynomorium coccineum. Many of the host species are first time reported while O. schultzii was the first record parasitizing woody plants.     

保水剂对梭梭（Haloxylon ammodendron）、白梭梭（Haloxylon persicum）种子萌发及幼苗根系的影响

在盆栽条件下,研究保水剂对梭梭（Haloxylon ammodendron）、白梭梭（Haloxylon persicum）种子萌发和幼苗根系形态的影响。结果表明：0.05%浓度的保水剂对梭梭、白梭梭种子萌发有明显的促进作用,发芽率较对照分别提高了18.7%和24.0%;0.05%浓度的保水剂能够抑制梭梭幼苗根系的垂直生长,有效促进侧根数量的增加和根系生物量的积累;0.1%浓度保水剂处理下,白梭梭的主根长度、侧根数量、根系生物量均达到最大;保水剂浓度达到0.2%时,梭梭、白梭梭种子萌发和幼苗根系的生长均受到抑制,表明梭梭幼苗生长最适宜的保水剂浓度为0.05%,白梭梭的浓度以0.05%～0.1%为宜。