Mycorrhizal status of plant species in the Chaco Serrano Woodland from central Argentina

We examined the mycorrhizal type of 128 plant species in two patches of native vegetation of the Chaco Serrano Woodland, central Argentina, the largest dry forest area in South America. Of the 128 plant species investigated (belonging to 111 genera in 53 families), 114 were colonized by arbuscular mycorrhizal fungi (AM), orchid mycorrhizal associations were present in the five terrestrial orchid species analyzed, one ectomycorrhiza was only present in Salix humboldtiana Willd., and 96 harbored a dark septate endophyte (DSE) association. Co-occurrence of AM and DSE was observed in 88 plant species. We determine morphological types of arbuscular mycorrhizal fungi (Arum, Paris, and intermediate AM structures) and report the mycorrhizal status in 106 new species, 12 of which are endemic to central Argentina and two, Aa achalensis Schltr. and Buddleja cordobensis Griseb., are declared to be vulnerable species. Root colonization in the Chaco Serrano Woodland is widespread and should be considered in revegetation programs due to the deterioration of this particular ecosystem. Considering the predominance of AM and DSE associations and the various potential benefits that these associations may bring to plant establishment, they should receive special attention in conservation and reforestation of these woodlands.     

A genetic contribution to the taxonomy ofOenothera sect.Oenothera (including subsectionsEuoenothera,Emersonia, Raimannia andMunzia)

Based on an analysis of results from experimental hybridization, the plants assigned byMunz toOenothera subg.Oenothera and subg.Raimannia, now divided into approximately 76 species, are referred to a single section,Oenothera. This section is in turn divided into five subsections:Euoenothera, Munzia, Raimannia, Emersonia, and an undescribed group of three species related toOenothera pubescens. Euoenothera is maintained in the traditional sense, and includes about 14 species of North America, widely naturalized elsewhere.Munzia consists of 45 species, comprising three series, and native to South America.Raimannia is restricted to a group of approximately 11 North American species.Emersonia comprises four rather heterogenous species of northern Mexico and southern New Mexico, of whichOenothera macrosceles, O. maysillesii, andO. organensis have been described. Within these four subsections, interspecific hybrids can be made in general, although plastid differentiation often leads to incompatibilities. With varying degrees of difficulty, hybrids were produced in all intersectional combinations involvingEuoenothera, Emersonia, Munzia, andRaimannia, the most difficult being those betweenEmersonia andRaimannia. Based on their habit and distribution,Emersonia species, and especiallyOenothera maysillesii, appear to resemble most closely the common ancestor of the section,Euoenothera andMunzia to have been derived from it or its common ancestor, andRaimannia perhaps to be more closely related to the phylogenetic branch that leads toEuoenothera.     

Taxonomic position of the cricket genus Eneopteroides Chopard, 1956 (Orthoptera: Grylloidea,Podoscirtidae), with descriptions of two new species

The cricket genus Eneopteroides Chopard, 1956 is transferred from the Eneopteridae to the Podoscirtidae owing to characters in external morphology and male genitalia. One species initially described in the genus Aphonomorphus Rehn, 1903, A. bicolor Hebard, 1928b, is transferred to Eneopteroides and two new species from western Amazonia are described, E. loretensis n. sp. and E. cordobensis n. sp.     

耐旱灌木互叶醉鱼草的生物学特性研究

互叶醉鱼草是我国西北干旱山区造林的优良灌木树种,对互叶醉鱼草在甘肃天祝县的分布及其采种母树进行了调查.对互叶醉鱼草的播种育苗、扦插育苗和造林试验进行了详细研究,扦插成活率可达75%,生根类型为皮部生根.干旱地区当年的造林成活率可达75%以上.这为今后互叶醉鱼草的开发利用和产业化经营提供依据.     

Three new species of Croton (Euphorbiaceae s.s.) from the Brazilian Caatinga

While conducting a floristic inventory of Croton from the Brazilian Caatinga, three new species were discovered. Croton arenosus, Croton glandulosobracteatus, and Croton harleyi are described and illustrated here. Based on morphological characters, Croton glandulosobracteatus is proposed to belong to section Barhamia, and C. arenosus and C. harleyi to section Geiseleria.     

盐沼草—白骨壤混种减轻污损动物危害的生物防治效果研究

广西北仑河口区新造高程约220 cm 的潮间带裸滩,移植白骨壤与茳芏、沟叶结缕草、芦苇和南水葱四种盐沼草进行混种,研究盐沼草-红树混种减轻污损动物对人工红树林危害的生物防治效果。结果表明：沟叶结缕草和茳芏可快速生长和扩展,缓流、促淤能力高于长势较差的南水葱和芦苇。在盐沼和白骨壤上发现19种污损动物,其中潮间藤壶、白条地藤壶、黑口滨螺和粗糙滨螺为优势种。茳芏和沟叶结缕草受污损程度较南水葱和芦苇轻。四种盐沼草受污损程度均低于白骨壤。白骨壤＋茳芏、白骨壤＋沟叶结缕草混种均可有效减轻污损动物对白骨壤苗木危害,这两类树-草混种处理区苗木的高度、叶数、枝数、枝下高和存活率等指标均较其他处理区好。初步判断“盐沼草-红树林协同生态修复体系”对于营造人工红树林有较高应用价值。     

New species of Allorhogas Gahan (Hymenoptera: Braconidae) reared from galls on Lycium cestroides Schltdl. (Solanaceae) in Argentina

Allorhogas cordobensis sp. nov. (Hymenoptera: Braconidae: Doryctinae) is described from the province of Córdoba, Argentina. Its representatives can be distinguished from all other known species of the genus by the unusual morphology of the ovipositor tip and the expanded clypeus apically. Remarkably, this species is also characterized by having a tridentate mandible, a feature known only in exodont braconids, mostly of the subfamily Alysiinae. The new species was reared from stem galls on Lycium cestroides, which constitutes the second record of an Allorhogas species associated with galls on representatives of the plant family Solanaceae.     

Tick-tock… says the moon and the sun: Daily activity patterns of mid-large-sized mammals in grassland-dominated landscapes afforested with Eucalyptus

Species can change their activity patterns in response to biotic and abiotic factors, such as sunlight and moonlight. The influence of these variables is a key question for ecological research and biodiversity conservation. The conversion of natural grasslands into tree plantations has reached high levels in temperate South America. These novel ecosystems elicit behavioural changes that can be detrimental or beneficial to wildlife. In this research, we describe the activity patterns of mammals (mid and large-sized) during sun and lunar phases using camera trap data (2015–2021; 22 926 camera/nights) to assess the effects of the season (warm and cold), habitat type (native forests, grasslands, Eucalyptus plantations) and landscape afforestation degree (10%–90%) in eight landscape samples (5 km radius) at Uruguayan grasslands. This represents the first study of temporal patterns in grassland afforestation worldwide, and concerning solar time and lunar patterns in Uruguay. Across 257 camera trap stations, 5297 independent detections of 13 species were recorded. While there were no significant differences among seasons nor through a landscape gradient of afforestation cover, the local habitat type affected most species temporal niches, finding significant differences between native ecosystems and Eucalyptus plantations, despite their close spatial proximity. Cathemeral and nocturnal activity patterns were seen for 12 species, and nine showed lunarphobic or lunarphilic trends according to habitat cover. In tree plantations, five of seven species narrowed their temporal activity compared to native habitats, and four changed their nocturnal activity. These alterations showed that several species adjust their daily activity patterns according to sun and moon phases under Eucalyptus plantations, probably reacting to changes in predation risk, hunting pressure, or foraging opportunities. Given that afforestation is projected to grow in southern South America, we must improve our understanding of how species adjust their activities in such novel ecosystems to identify measures needed to increase their conservation opportunities.     

The Bt gene <Emphasis Type="Italic">cry2Aa2</Emphasis> driven by a tissue specific ST-LS1 promoter from potato effectively controls <Emphasis Type="Italic">Heliothis virescens</Emphasis>

Expression of the Cry2Aa2 protein was targeted specifically to the green tissues of transgenic tobacco Nicotiana tabacum cv. Xanthi plants. This deployment was achieved by using the promoter region of the gene encoding the Solanum tuberosum leaf and stem specific (ST-LS1) protein. The accumulated levels of toxin in the leaves were found to be effective in achieving 100 mortality of Heliothis virescens larvae. The levels of Cry2Aa2 expression in the leaves of these transgenic plants were up to 0.21 of the total soluble proteins. Bioassays with R₁ transgenic plants indicated the inheritance of cry2Aa2 in the progeny plants. Tissue-specific expression of the Bt toxin in transgenic plants may help in controlling the potential occurrence of insect resistance by limiting the amount of toxin to only predated tissues. The results reported here validate the use of the ST-LS1 gene promoter for a targeted expression of Bt toxins in green tissues of plants.     

<Emphasis Type="Italic">Croton borbensis</Emphasis>, a new species of Euphorbiaceae from white sands of Amazonian Brazil

A new species of Euphorbiaceae, Croton borbensis, is described and illustrated from western Amazonian Brazil. It shares features similar to another white sand Amazonian species, C. dissectistipulatus, but differs in having leaves with a serrulate-glandulose margin, no evident stipules, staminate flowers with six stamens and glabrous pedicels, pistillate flowers with few, shortly stipitate glands on the calyx, and a glabrous ovary. Croton borbensis is tentatively placed in section Barhamia.     

Seed formation in two species of Adesmia (Fabaceae): co‐occurrence of micropylar and lateral endosperm haustoria in legumes and its taxonomic value

Seed ontogeny of Adesmia bicolor and Adesmia latifolia was analysed using light microscopy and standard histological techniques. Fertilization was porogamic. Linear proembryonal tetrads were observed in A. bicolor. The robust elongated suspensors possessed specialized basal cells. The nucellar epidermis became endothelial. The free‐nuclear endosperm produced a micropylar, filamentous and ephemeral haustorium and a lateral sac‐like haustorium at the funicular side. The cellular endosperm was initiated from the micropylar zone after the cordiform embryo stage. It mostly disintegrated in mature seeds. The sclerified bilayered testa was derived from the outer ovular integument. Different astrosclereid arrangements beyond the lens in both Adesmia species may be related to the different habitats of the two species. The occurrence of both micropylar and lateral nuclear endosperm haustoria has so far not been reported in Fabaceae and is the most distinctive embryological character of Adesmieae. The taxonomic value of the mostly uniform morphology of the suspensor in the Adesmia species studied could also be relevant. The nature of seed endothelia in many Fabaceae requires accurate redetermination prior to taxonomic use. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 602–612.     

Rhizobial infection in Adesmia bicolor (Fabaceae) roots

The native legume Adesmia bicolor shows nitrogen fixation efficiency via symbiosis with soil rhizobia. The infection mechanism by means of which rhizobia infect their roots has not been fully elucidated to date. Therefore, the purpose of the present study was to identify the infection mechanism in Adesmia bicolor roots. To this end, inoculated roots were processed following conventional methods as part of our root anatomy study, and the shape and distribution of root nodules were analyzed as well. Neither root hairs nor infection threads were observed in the root system, whereas infection sites—later forming nodules—were observed in the longitudinal sections. Nodules were found to form between the main root and the lateral roots. It can be concluded that in Adesmia bicolor, a bacterial crack entry infection mechanism prevails and that such mechanism could be an adaptive strategy of this species which is typical of arid environments.     

Molecular evolution of 5S rDNA of Solanum species (sect. Petota): application for molecular phylogeny and breeding

Nucleotide sequences of 5S rRNA genes (5S rDNA) of 26 wild species of the genus Solanum (sect. Petota) originating from Middle or South America, four Solanum tuberosum breeding lines and one European species, Solanum dulcamara (sect. Dulcamara) were compared with each other and with the 5S rDNA of Lycopersicon esculentum. The length of the repeat ranges from 285 bp to 349 bp. The complete 5S repeat unit consists of the 120-bp long conserved coding region and of a intergenic spacer with a high variability in the central portion as result of deletions/duplications of short motifs demonstrating sequence similarity to box C in the 5S rRNA coding region. Numerous structural rearrangements found in the spacer region can be applied to design species-specific molecular markers for Solanum species involved in breeding programs. Characteristic insertions/deletions (indels) were used to reconstruct phylogenetic relationships among the species studied. S. dulcamara forms a separate clade; L. esculentum is more related to Solanum species of sect. Petota. Conservation of ancestral 5S spacer organization was demonstrated for the representatives of several series of sect. Petota, both Stellata and Rotata. Further rearrangements of the spacer organization occurred in at least four independent lineages: (1) L. esculentum, (2) ser. Polyadenia, (3) other Stellata species from Middle America (ser. Pinnatisecta and Bulbocastana), (4) superser. Rotata. In this last group, series Megistacroloba and Conocibaccata show a common origin, and separation from ser. Tuberosa. Solanum chacoense and Solanum maglia demonstrate a close relatedness to species of ser. Tuberosa and should be included into this group, whereas Solanum bukasovii should be excluded due to conservation of ancestral spacer organization. Three major subgroups may be distinguished for species from ser. Tuberosa, although a high sequence similarity was found here. Several wild species (diploids Solanum phureja and Solanum spegazzinii) probably participated in the natural origin of tetraploid S. tuberosum;others were later used for crossing in breeding programs (e.g. Solanum demissum). Clear separation of Middle-American Stellata species from South-American Stellata and from Middle-American Rotata polyploids is shown. Received: 11 January 2001 / Accepted: 18 April 2001     

退耕还林对地面蜘蛛种群的影响

为探究退耕还林对地面蜘蛛群落的影响,分别于2014和2015年3月—9月期间,采用陷阱法对北京市顺义区南彩镇退耕还林已2a和3a的林带及相邻原非作物生境林带中地面蜘蛛的活动密度进行了系统调查和分析。结果,2014年在调查区域共采集地面蜘蛛1465头,隶属8科18属32种,2015年共收集地面蜘蛛2186头,隶属10科25属45种;退耕还林以后蜘蛛类群发生改变,地面蜘蛛丰富度增加,而部分农田蜘蛛消失;2014年原非作物生境林带中地面蜘蛛的多样性指数、丰富度都极显著高于退耕还林林带(P0.01),均匀性指数不存在显著差异,2015年两个林带的多样性指数仍存在极显著差异(P0.01),丰富度存在显著差异(P0.05),均匀性指数之间不存在显著差异;退耕还林以后第3年新建林带和原非作物生境林带中地面蜘蛛的活动密度随时间的变化趋势相近。研究结果表明:顺义地区退耕还林工程实施3a以后,新建人工林仍处于生境重建阶段,未完全达到稳定状态,退耕还林以后第3年新建林带中地面蜘蛛群落的稳定性高于第2年。退耕还林通过改变原有农田生态系统的植被种类、结构、人为管理等方式,使原有农田生态系统发生了根本性的改变。持续研究退耕还林对地面蜘蛛的类群变化的影响对生境受到干扰后生物群落变化过程的认识有理论意义。     

A new species of “sangre de drago” (Croton section Cyclostigma, Euphorbiaceae) from coastal Ecuador

Croton churutensis is described as a new species ofCroton sectionCyclostigma endemic to lowland deciduous forests in coastal Ecuador. Its red latex is used locally in Guayas Province to treat wounds, stomach ulcers, and some skin conditions caused by fungal infections. The new species differs from its closest apparent relative,Croton hibiscifolius, in its arching-pendent inflorescences, short-pedicellate female flowers with quadrifid stigmas, more numerous stamens, laciniate stipules, and lower elevation habitat.     

Antifungal activity of essential oils of Croton species from the Brazilian Caatinga biome

Aims: To find new antifungal agents among essential oils from Brazilian Croton species. Methods and Results: Plant leaves were steam distilled and the obtained essential oils were analyzed by gas chromatography/mass spectroscopy. The main constituents were estragole and anethole for Croton zehntneri, methyl-eugenol and bicyclogermacrene for Croton nepetaefolius and spathulenol and bicyclogermacrene for Croton argyrophylloides. The antifungal activity of essential oils was evaluated against Candida albicans, Candida tropicalis and Microsporum canis by the agar-well diffusion method and the minimum inhibitory concentration (MIC) by the broth microdilution method. Essential oils of Croton species demonstrated better activity against M. canis. Among the three plants C. argyrophylloides showed the best results, with MIC ranging from 9 to 19 μg ml⁻¹. The acute administration of the essential oil up to 3 g kg⁻¹ by the oral route to mice was devoid of overt toxicity. Conclusions: The studied essential oils are active in vitro against the dermatophyte M. canis and present relative lack of acute toxicity in vivo. Significance and Impact of the Study: Because of its antifungal activity and low toxicity, the essential oils of studied Croton species are promising sources for new phytotherapeutic agents to treat dermatophytosis.     

A selective insecticidal protein from Pseudomonas mosselii for corn rootworm control

The coleopteran insect western corn rootworm (WCR, Diabrotica virgifera virgifera) is an economically important pest in North America and Europe. Transgenic corn plants producing Bacillus thuringiensis (Bt) insecticidal proteins have been useful against this devastating pest, but evolution of resistance has reduced their efficacy. Here, we report the discovery of a novel insecticidal protein, PIP‐47Aa, from an isolate of Pseudomonas mosselii. PIP‐47Aa sequence shows no shared motifs, domains or signatures with other known proteins. Recombinant PIP‐47Aa kills WCR, two other corn rootworm pests (Diabrotica barberi and Diabrotica undecimpunctata howardi) and two other beetle species (Diabrotica speciosa and Phyllotreta cruciferae), but it was not toxic to the spotted lady beetle (Coleomegilla maculata) or seven species of Lepidoptera and Hemiptera. Transgenic corn plants expressing PIP‐47Aa show significant protection from root damage by WCR. PIP‐47Aa kills a WCR strain resistant to mCry3A and does not share rootworm midgut binding sites with mCry3A or AfIP‐1A/1B from Alcaligenes that acts like Cry34Ab1/Cry35Ab1. Our results indicate that PIP‐47Aa is a novel insecticidal protein for controlling the corn rootworm pests.     

气候变化驱动下黄土高原刺槐林气候适宜性和脆弱性

刺槐是黄土高原乡土树种,具有优良的水土保持和固碳功能。黄土高原生态恢复实践中实施了大规模的植树造林,刺槐林面积占沟壑丘陵区人工植树造林面积90%以上。由于种植时没有考虑刺槐的气候适宜性,一些地区的刺槐林出现了退化现象。采用最大熵模型,在0.5km×0.5km空间精度上分别模拟了1961—1990、1966—1995、1971—2000、1976—2005、1981—2010,以及2100年(典型浓度路径RCP4.5和RCP8.5气候情景下)黄土高原刺槐的气候适宜性和敏感性。模拟结果显示：黄土高原刺槐分布及其动态变化主要受到最冷月温度、极端低温、降水量、年辐射量等气候因子影响,低温(最冷月温度、极端低温)是影响刺槐的最关键因子。黄土高原西北和北部广大地区,自然环境条件不适合刺槐林生长;黄土高原东南部(关中平原和山西南部)比较适合刺槐生长。相对1961—1990年,1961—2010年期间刺槐林适宜区分布格局基本没有改变,RCP4.5和RCP8.5气候情景下刺槐林适宜区分布格局也没有显著改变。图层叠加分析发现,刺槐的气候适宜度(即存在概率)发生了明显改变。黄土高原西部和北部属于不适宜刺槐生...     

Effects of elevated CO2 on five plant-aphid interactions

We investigated interactions between five species of phloem-feeding aphids (Homoptera: Aphididae) and their host plants at elevated CO₂; Acyrthosiphon pisum (Harris) on Vicia faba L., Aphis nerii Boyer de Fonscolombe on Asclepias syriaca L., Aphis oenotherae Oestlund on Oenothera biennis L., Aulacorthum solani (Kaltenbach) on Nicotiana sylvestris Speg. & Comes and Myzus persicae (Sulzer) on Solanum dulcamara L. Host plants grown at elevated CO₂ generally had greater biomass, leaf area and C:N ratios than those grown at ambient CO₂, while plants with aphids had lower biomass and leaf area than those without aphids.The responses of aphid populations to elevated CO₂ were species-specific with one species increasing (M. persicae), one decreasing (A. pisum), and the other three being unaffected. CO₂ treatment did not affect the proportion of alate individuals produced. In general, aphid abundance was not significantly related to foliar nitrogen concentration.We performed separate analyses to test whether either aphid presence or aphid abundance modified the response of host plants to elevated CO₂. In terms of aphid presence, only three of the potential 15 interactions (five aphid species x three plant traits) were significant; A. solani slightly modified the response of the plant biomass to elevated CO₂ and M. persicae affected the response of leaf area and allocation. In terms of aphid abundance, only two of the potential 15 interactions were significant with A. nerii modifying the plant response to CO₂ in terms of total leaf area and allocation.We conclude that, in contrast to other insect groups such as leaf chewers, populations of most phloem-feeders may not be negatively affected by increased CO₂ concentrations in the future. The reasons for this difference include the possibility that aphids may be able to compensate for changes in host plant quality by altering feeding behaviour or by synthesizing amino acids. In addition, there is little evidence that aphid herbivory, even at high levels, will substantially modify the response of plants to elevated CO₂.     

An integrated assessment of wild vegetable resources in Inner Mongolian Autonomous Region, China

Mwingi District lies within the Kenyan Arid and Semiarid lands (ASALs) in Eastern Province. Although some ethnobotanical surveys have been undertaken in some arid and semiarid areas of Kenya, limited studies have documented priority medicinal plants as well as local people's awareness of conservation needs of these plants. This study sought to establish the priority traditional medicinal plants used for human, livestock healthcare, and those used for protecting stored grains against pest infestation in Mwingi district. Further, the status of knowledge among the local people on the threat and conservation status of important medicinal species was documented. This study identified 18 species which were regarded as priority traditional medicinal plants for human health. In terms of priority, 8 were classified as moderate, 6 high, while 4 were ranked highest priority species. These four species are Albizia amara (Roxb.) Boiv. (Mimosacaeae), Aloe secundiflora (Engl. (Aloaceae), Acalypha fruticosa Forssk. (Euphorbiaceae) and Salvadora persica L. (Salvadoraceae). In regard to medicinal plants used for ethnoveterinary purposes, eleven species were identified while seven species were reported as being important for obtaining natural products or concoctions used for stored grain preservation especially against weevils. The data obtained revealed that there were new records of priority medicinal plants which had not been documented as priority species in the past. Results on conservation status of these plants showed that more than 80% of the respondents were unaware that wild medicinal plants were declining, and, consequently, few of them have any domesticated species. Some of the species that have been conserved on farm or deliberately allowed to persist when wild habitats are converted into agricultural lands include: Croton megalocarpus Hutch., Aloe secundiflora, Azadirachta indica A. Juss., Warburgia ugandensis Sprague, Ricinus communis L. and Terminalia brownie Fresen. A small proportion of the respondents however, were aware of the threats facing medicnal plants. Some of the plants reported as declining include, Solanum renschii Vatke (Solanaceae), Populus ilicifolia (Engl.) Rouleau (Salicaceae), Strychnos henningsii Gilg (Loganiaceae) and Rumex usambarensis (Dammer) Dammer (Polygonaceae). Considering the low level of understanding of conservation concerns for these species, there is need therefore, to build capacity among the local communities in this area particularly in regard to sustainable use of natural resources, conservation methods as well as domestication processes.