Host range of the defoliator Strepsicrates sp. is too broad for biological control of the invasive weed Rhodomyrtus tomentosa

In its native range the invasive weed, Rhodomyrtus tomentosa is host to a suite of herbivores. One, Strepsicrates sp. (Lepidoptera: Tortricidae), was collected in China in 2014, introduced under quarantine in Florida, USA, and tested against related species to determine its host range and suitability for biological control. In no-choice tests, neonates fed and completed development to the pupal stage on several species of Myrtaceae, including the target weed R. tomentosa, the exotics Melaleuca quinquenervia, and Eucalyptus camaldulensis, and three native species, Eugenia axillaris, Mosiera longipes and Morella cerifera (Myricaceae). Due to the broad host range exhibited in quarantine testing, this species will not be pursued as a biological control agent of R. tomentosa.     

The shrub Rhodomyrtus tomentosa acts as a nurse plant for seedlings differing in shade tolerance in degraded land of South China

Questions: What are the nurse effects of Rhodomyrtus tomentosa in degraded land of South China? Are canopy or soil factors responsible for the main nurse effect? Do facilitative effects increase with the shade tolerance of the target species? Location: Degraded shrubland in South China. Methods: Seedlings of three native climax woody species (Schima superba, Michelia macclurei, Castanopsis fissa) that differ in shade tolerance were subjected to four treatments by transplantation: (1) under the canopy of R. tomentosa shrubs; (2) in open interspaces without vegetation cover (control); (3) under the canopy of R. tomentosa from which canopies had been removed; and (4) in open interspaces without vegetation but covered by branches and leaves of R. tomentosa. Results: At low soil nutrient levels, increased canopy shade, soil porosity and soil moisture under the canopy of R. tomentosa increased seedling survival of the climax tree species S. superba, C. fissa and M. macclurei, and shoot height of S. superba. The nurse effect (a form of facilitation) of R. tomentosa depended more on canopy shade than on soil amelioration. The magnitude of facilitation or nurse effect was positively correlated with shade tolerance of the target species. Conclusions: Use of nurse plants in restoration differs from traditional reforestation (clearing and/or burning to reduce interspecific competition between target tree species and non‐target species) because it focuses on positive interactions between nurse plants and target plants that increase establishment of target species and reduce time required for restoration. Because nurse effects of R. tomentosa shrubs tended to be larger on target species with greater shade tolerance, shade‐tolerant plants are suggested as target species to accelerate restoration.     

Examining the phylogeny of the Australasian Lymnaeidae (Heterobranchia: Pulmonata: Gastropoda) using mitochondrial, nuclear and morphological markers

We examined the species groups relationships of the freshwater snail genus Austropeplea using mitochondrial, nuclear and morphological markers in addition to traditional methods of shell shape analysis. Based primarily on the results of a combined molecular and morphological analysis, samples of the nominal species A. tomentosa form distinct lineages. The New Zealand populations of A. tomentosa are a very distinct lineage from any of the Australian populations attributed to A. tomentosa. Furthermore, within the Australian group, three lineages, south Australia, Tasmania and eastern Australia, appear to have undergone recent and/or rapid speciation events. Samples assigned to A. lessoni were resolved as two distinct lineages, representing the eastern and northern Australian populations. Kutikina hispida was resolved within the Australian A. tomentosa clade. Molecular results for A. viridis suggests that it is also composed of at least two distinct lineages that could be treated as species. Incongruence observed between the single mitochondrial, nuclear and morphological topologies highlight the importance of using a number of different datasets in the delimitation of species-group taxa.     

Pollination and breeding system of Melochia tomentosa L. (Malvaceae), a keystone floral resource in the Brazilian Caatinga

The main goals of the present paper were to investigate the floral biology and the breeding system of Melochia tomentosa in a semi-arid region in Brazil, comparing the role of Apis mellifera with other native pollinators, and to discuss the importance of this plant species as a floral resource for the local fauna in maintaining different guilds of specialized pollinators in the Caatinga. M. tomentosa is very common in Caatinga areas and blooms year-round with two flowering peaks, one in the wet and another in the dry period. The pink, bright-colored flowers are distylous and both morphs are homogamous. The trichomatic nectary is located on the inner surface of the connate sepals, and the nectar (ca. 7 μl) is accumulated in the space between the corolla and the calyx. Nectar sugar concentration reaches an average of 28%. The results of controlled pollination experiments show that M. tomentosa is self-incompatible. Pollen viability varies from 94% to 98%. In spite of being visited by several pollen vectors, flower attributes of M. tomentosa point to melittophily, and A. mellifera was the most frequent visitor and the principal pollinator. Although honeybees are exotic, severely competing with native pollinators, they are important together with other native bees, like Centris and Xylocopa species, for the fruit set of M. tomentosa. This species represents a keystone floral resource favoring the maintenance of many species of bees, butterflies and hummingbirds through the year in this deciduous tropical dry forest.     

三倍体毛白杨不同组织内生细菌多样性分析

【背景】三倍体毛白杨非常适合黄河区域生态经济发展,是我国林业推广项目的重要树种。内生细菌在三倍体毛白杨不同组织中广泛存在,对三倍体毛白杨具有防病、促生、固氮和生物修复等生物学作用。【目的】通过分析三倍体毛白杨不同组织内生细菌多样性,可以充分挖掘其蕴含的丰富微生物资源。【方法】以北京林业大学山东冠县毛白杨基地的三倍体毛白杨为材料,应用16S rRNA基因高通量测序技术对其根、茎、叶中内生细菌多样性进行了分析,阐述三倍体毛白杨不同组织内生细菌多样性的变化趋势和规律,为其内生细菌的进一步应用奠定理论基础。【结果】三倍体毛白杨根部内生细菌群落丰富度及多样性最高,叶片中最低。高通量测序结果显示,在全部样本中,假单胞菌门和放线菌门为优势门,伯克氏菌属(Burkholderia)、假诺卡氏菌属(Pseudonocardia)和食酸菌属(Acidovorax)为优势属,不同组织的内生细菌群落结构组成差异显著;16S rRNA基因功能预测结果显示,三倍体毛白杨内生细菌的功能主要涉及氨基酸代谢、维生素代谢、芳香族化合物降解和糖酵解等。通过分离培养共获得217株内生细菌,分属于23个属44个种,其中有4株1...     

Carex tomentosa versus C. filiformis (Cyperaceae): the long‐standing debate comes to its happy end

The type of Carex filiformis is an illustration, which is pluri‐interpretable and therefore an epitype is designated here. As epitypified, C. filiformis L. becomes synonymous with Carex montana L. (the latter getting priority), and therefore not the correct name for Carex tomentosa L. as stated by Nelmes and other authors. Carex tomentosa is the accepted name for the taxon sometimes referred to as C. filiformis.     

Predicting the post-fire establishment and persistence of an invasive tree species across a complex landscape

The reintroduction of pre-European fire regimes has allowed the entry of many invasive plant species into fire-dependant ecosystems of North America. However, the environmental factors that favor the post-fire establishment of these species across complex landscapes are not well understood and the initial establishment of invasive species does not necessarily result in long-term persistence. To evaluate the post-fire establishment and persistence of disturbance-dependent invasive plants, we studied the invasion of Paulownia tomentosa (princess tree, an early-successional species introduced from Asia) across three burns in the southern Appalachian Mountains. Based upon classification tree analysis, the presence/absence of P. tomentosa 2 years after burning was most strongly related to the cover of residual vegetation, topographic shading, and moisture availability. Spatial application of classification tree models to repeated survey data showed that P. tomentosa established across a wide range of microsites 2 years after burning. However, predicted habitat for P. tomentosa decreased by 63% 4 years after fire and by 73% 6 years after fire. Following its initial widespread establishment, P. tomentosa only persisted on xeric and exposed topographic positions that experienced high intensity burning. However, the sites where it persisted include rare community types that contain two endangered plant species that depend upon fire for successful reproduction. The control of P. tomentosa on these ecologically important sites may require special attention from land managers.     

Protective effect of Premna tomentosa extract (L. verbanacae) on acetaminophen-induced mitochondrial dysfunction in rats

Allurement of herbs as health beneficial foods (physiologically functional foods) and as a source material for the development of new drugs, has led to greater furtherance in the study of herbal medicines during recent years. Plant extracts are being utilized to treat a wide variety of diseases like hepatotoxicity. Premna tomentosa is one such medicinal plant used widely in Indian ayurvedic medicine for the treatment of liver disorders. This study appraised the effectiveness of P. tomentosa leaf extract in protecting the liver against mitochondrial damage induced by acetaminophen, since mitochondrial injury has been investigated as a potential initiator of hepatotoxicity. Normal Wistar strain rats were pre-treated with P. tomentosa extract (750 mg/kg, orally) for 15 days and then intoxicated with acetaminophen (640 mg/kg, orally). Mitochondria were isolated from liver of experimental animals and assessed for the levels of lipid peroxide products, GSH and mitochondrial enzymes (isocitrate dehydrogenase, -keto glutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, NADH dehydrogenase and cytochrome-C-oxidase). The levels of Lipid peroxidation products were increased and the levels of the other assessed parameters were significantly decreased in hepatotoxicity induced animals. Whereas, the levels were brought back to normal in P. tomentosa pre-treated rats, which shows the protective effect of the extract against mitochondrial damage. Presence of anti-oxidant compound d-limonene (58%) in P. tomentosa leaves, which is known to enhance conjugation of toxic metabolites by maintaining liver GSH concentrations may explain the hepatoprotective property of the extract.     

Non-selective feeding and oviposition behaviour of Cryptocephalus trifasciata (Coleoptera: Cerambycidae: Cryptocephalinae) precludes its use as a biological control agent for downy rose myrtle (Rhodomyrtus tomentosa)*

Downy rose myrtle (Rhodomyrtus tomentosa), a southeast Asian native shrub, invades natural areas in Florida and Hawaii, where it forms dense, impenetrable thickets. We tested the host affinity and survivorship of a case-bearing beetle, Cryptocephalus trifasciata on R. tomentosa and related species. C. trifasciata adults and larvae fed, oviposited and/or completed development on all non-target species tested (N?=?11). C. trifasciata has a broad host range and is unsuitable for use as a biological control agent.     

A comparative study of cleaning activity of two reef fishes at Fernando de Noronha Archipelago,tropical West Atlantic

Cleaner fishes are usually classified as obligate or facultative cleaners according to their diet and the extent to which their nutritional requirements in the different ontogenetic stages are gained from cleaning. While obligate cleaners clean throughout their lives and ingest mainly food taken from the clients’ body surface, facultative cleaners clean only as juveniles and have a broader diet. In addition, some facultative cleaners may experience a relatively higher predation risk, and thus rarely interact with piscivorous fishes. Despite these acknowledged differences, there are very few studies that compare cleaning activity of obligate and facultative cleaners within the same area. Cleaning activity of the obligate cleaner goby Elacatinus cf. randalli and the facultative cleaner wrasse Thalassoma noronhanum were comparatively examined at Fernando de Noronha Archipelago, tropical West Atlantic. The client assemblage attended by the two cleaners differed, as the goby attended a slightly greater diversity of species (22), mostly piscivores and zoobenthivores, and the wrasse attended fewer species (19), mostly planktivores. Chromis multilineata was the most common client species of both cleaners, although body size (which is expected to be positively correlated to clients’ ectoparasite load) of C. multilineata individuals attended by the goby was larger than that of the individuals attended by the wrasse. Despite such differences, T. noronhanum showed a surprisingly species-rich client assemblage when compared with other cleaners of the genus Thalassoma. In addition, the frequency and time spent on cleaning interactions, as well as the number of client species attended per 10-min period, was similar for both cleaner species, which indicate that they have important yet complimentary ecological roles in the reef community at Fernando de Noronha Archipelago.     

The recent colonization of south Brazil by the Azores chromis Chromis limbata

The damselfish Chromis limbata is native to the Macaronesian Archipelagos (Azores, Madeira and Canaries) and the western coast of Africa between Senegal and Angola. During the austral summers of 2008 and 2009 the species was recorded for the first time in the south‐western Atlantic Ocean around Campeche and Xavier Islands, in Florianópolis, Santa Catarina State, Brazil. Here, the progression of C. limbata in southern Brazilian waters is described using visual counts and genetic surveys and changes in the density of the native congener Chromis multilineata were also investigated. Underwater visual censuses of both Chromis species were carried out from 2009 to 2014. Chromis limbata tissue samples were collected and the mtDNA control region was sequenced and compared with mtDNA haplotypes from the natural range to confirm species identity, compare genetic diversity and to infer connectivity between newly established Brazilian populations. The Brazilian population of C. limbata increased significantly over the past 5 years and the effect on C. multilineata is still an open question, longer time‐series data will be necessary to clarify possible interactions. The molecular analyses confirmed species identity, revealed strong haplotype connectivity among Brazilian study sites and showed a low genetic diversity in Brazil when compared with the native populations, suggesting few individuals started the invasion. Four hypotheses could explain this colonizing event: C. limbata was released by aquarium fish keepers; larvae or juveniles were transported via ship ballast water; the species has rafted alongside oil rigs; they crossed the Atlantic Ocean through normal larval dispersal or naturally rafting alongside drifting objects. The rafting hypotheses are favoured, but all four possibilities are plausible and could have happened in combination.     

Cardenolides from Gomphocarpus sinaicus and Pergularia tomentosa (Apocynaceae: Asclepiadoideae) deter the feeding of Spodoptera littoralis

Methanol extracts of Gomphocarpus sinaicus, Pergularia tomentosa and Cynanchum acutum (Apocynaceae, sub-family Asclepiadoideae) deterred feeding of Spodoptera littoralis in a binary-choice bioassay. Analyses of extracts using high-performance liquid chromatography with photodiode array detection indicated that methanol extracts of P. tomentosa and G. sinaicus contained cardenolides, while these compounds were not detected in extracts of C. acutum. Activity-guided fractionation of the methanol extracts of G. sinaicus and P. tomentosa resulted in the isolation of six cardenolides: 7,8-dehydrocalotropin, calotropin and coroglaucigenin 3-(6-deoxy-β-allopyranoside)-19-acetate (frugoside 19-acetate) from G. sinaicus, and coroglaucigenin, 16α-acetoxycalotropin and calactin from P. tomentosa. The isolation of 16α-acetoxycalotropin was a new report from P. tomentosa. Each of the 6 cardenolides deterred feeding by S. littoralis, while two cardenolide standards, digoxin and digitoxin, did not affect feeding. Differences among cardenolides in their effect on feeding were associated with specific structural features. C. acutum is the only one of the three species tested that is known to support the development of S. littoralis, although the development of larvae was delayed. The observed feeding deterrent activity of the cardenolide-free methanol extract of C. acutum would suggest that compounds other than cardenolides are responsible for the deterrent activity. These compounds, although deterrent in a short-term feeding assay, might not prevent long term feeding, thus allowing the larvae to develop on the plant.     

Oospores of <Emphasis Type="Italic">Chara tomentosa</Emphasis> from Holocene sediments of Lake Zeribar (Iran)

Biometric measurements were performed on oospores of Chara tomentosa from Core 63-J from Lake Zeribar in Iran. The partially fossilized oospores examined did not differ significantly in dimensional measurements, number of ridges, or colour from oospores of modern specimens of C. tomentosa.     

Effect of environmental conditions on decomposition in eight woody species of a dry tropical forest

Litter decay is a significant part of carbon budget. Due to strong environmental control, the changes in the environment may drastically influence the litter decay rates. Litter decomposition of eight dry tropical woody species, viz. Shorea robusta, Buchanania lanzan, Diospyros melanoxylon, Lagerstroemia parviflora, Lannea coromandelica, Terminalia tomentosa, Holarrhena antidysenterica and Lantana camara was studied to document the effect of intra-annual changes in the environment. Litter decomposition was monitored at monthly intervals at five sites using litter bag technique over an annual cycle in a dry tropical deciduous forest of Vindhyan highland, India. Weight loss differed among species and through months, and ranged from 15.38% in L. camara at Kotwa site in January to 30.72% in T. tomentosa at Hathinala site in August. Peak weight loss occurred in August and averaged 46.2% across species and sites. Nitrogen and phosphorus mineralization rates also varied significantly from species to species. T. tomentosa having higher nitrogen content and lower C/N ratio than other species exhibited faster weight loss. Nitrogen and phosphorus contents of litter showed significant positive correlation with weight loss. C/N ratio was negatively related to decay constant, and the weight loss was positively related to the soil surface temperature as well as soil moisture content.     

不同种源桃金娘表型性状多样性研究

为解析桃金娘表型性状多样性及其种源间关系，该文以20个不同来源的桃金娘为研究对象，在同质园栽培条件下，对其营养器官和花器官表型性状进行观测，采用方差分析、变异分析、Shannon-Wiener多样性指数分析和聚类分析等方法，探讨不同种源桃金娘表型性状多样性。结果表明：(1)不同种源桃金娘表型性状存在显著差异(P<0.05),Shannon-Wiener多样性指数均值在1.35以上，表型性状多样性丰富。(2)种源内表型性状变异系数均值在10.81%～63.75%之间，种源间的变异系数均值在13.08%～74.04%之间，种源间变异(23.33%)高于种源内变异(19.79%),营养器官变异(29.52%)高于花器官变异(14.06%)。(3)部分性状存在极显著或显著相关性，株高与分枝数呈极显著负相关，而与叶长、叶宽和叶面积等却呈显著正相关。(4)在欧式距离10处，20个种源桃金娘可分为A、B、C三类，A类包含8个种源，该类种源表现为植株高大、分枝少、叶大和花大等特征；B类包含11个种源，该类种源表现为株高中等、叶较大和花中等等特征；C类仅包含1个种源，表现为植株低矮、分枝多、叶小和...     

毛白杨蔗糖合酶基因PtSS2克隆与表达分析

为了解毛白杨蔗糖合酶(sucrose synthase,SS)基因功能和表达模式,以毛白杨茎段来源的cDNA为模板,根据毛果杨PtrSS2CDS序列信息设计特异引物,采用RT-PCR技术分离克隆了PtSS2基因。测序分析表明,PtSS2基因序列全长为2 412bp,编码803个氨基酸,蛋白大小为92.14kD,理论等电点6.00,属于酸性蛋白;氨基酸序列同源性分析表明,PtSS2与毛果杨PtrSS2和PtrSS1一致性分别高达100%和98.63%;结构域分析表明,PtSS2含有2个高度保守的功能域,即蔗糖合酶(5~552)和糖基化转移酶(554~744)功能域。qRT-PCR检测表明,PtSS2在毛白杨根、茎、叶、营养芽、雄雌花芽等各个组织中均有表达,但在营养芽和花芽中表达量较高,根部相对较低,总体呈组成型表达模式;在干旱胁迫下,PtSS2表达水平提升。研究结果推测,蔗糖合酶基因PtSS2在毛白杨各组织器官发育过程及干旱胁迫响应过程中具有重要功能。     

尾叶桉林下5种植物的耐阴性、生物量及其个体消长

为了解尾叶桉林下不同植物种类的生理生态特性和生长适应性,在鹤山站尾叶桉林中选取分布较多且药用价值和经济价值较高的5种林下植物为研究对象,测定各植物的叶片特征、叶绿素含量和光合-光响应曲线,同时结合2006年和2011年尾叶桉林的样方调查数据分析了5种林下植物生物量的变化和个体数量的消长。结果表明:(1)野牡丹叶片的宽度、厚度、单片叶面积等指标最大,梅叶冬青最小,桃金娘、栀子和山苍子处于两者之间;桃金娘、野牡丹和山苍子的光合速率随光照的增强迅速增大,其光饱和点较高;梅叶冬青和栀子的光合速率也随光照的增强而增大,但其斜率比野牡丹和山苍子大,并很快就达到光饱和点。综合聚类分析植物的耐阴程度,5种植物可分为2类:第1类为耐阴性较强的梅叶冬青、栀子,第2类为耐阴性较弱的野牡丹、山苍子和桃金娘。(2)随着尾叶桉林的生长,5种林下植物的生物量都有不同程度的增加,其中增幅较大的是野牡丹和桃金娘分别增加74倍和18倍,增幅最小的是栀子仅1.3倍。野牡丹、桃金娘和山苍子这3个种生物量的增加主要是由个体高度和地径的增长引起,而栀子和梅叶冬青生物量的增加是其个体数量、株高和地径做出的贡献。(3)在尾叶桉林生长过程中,耐阴种类梅叶冬青随着个体密度、株高和地径的增长,其在林内发展成为主要优势灌木种类;栀子的密度虽然有一定的增大,但其株高和地径增加量小,生物量也小,发展为次要灌木种类。野牡丹、桃金娘和山苍子等3种的个体密度都在下降,虽然其地径、株高和生物量也有一定的增长,但其较强的阳生性不能适应林内的荫蔽环境,只适于林窗或林缘光照较强的地方生长。因此,在桉树林经营管理过程中应适当保护和种植梅叶冬青和栀子;在短轮伐期经营模式下,林窗和林缘也可适当保留野牡丹、桃金娘和山苍子。     

Thladiantha tomentosa (Cucurbitaceae) comb. nov. from southwestern China

In this paper, we propose that Thladiantha cordifolia (Blume) Cogn. var. tomentosa A. M. Lu & Z. Y. Zhang should be recognized at species rank as Thladiantha tomentosa (A. M. Lu & Z. Y. Zhang) W. Jiang & H. Wang. This species is similar to T. cordifolia and T. angustisepala W. J. de Wilde & Duyfjes, from which it differs mainly by having ovate bracts, linear sepals, and ellipsoidal, rostrate, ribbed verrucose fruits.     

The effect of magnetic field on <Emphasis Type="Italic">Paulownia</Emphasis> tissue cultures

In this study, in vitro tissue cultures of Paulownia tomentosa and Paulownia fortunei were prepared and then exposed to a magnetic flow density of 2.9–4.8 mT and 1 m s⁻¹ flow rate for a period of 0, 2.2, 6.6 and 19.8 s. The magnetic field (MF) increased the regeneration capability of Paulownia cultures and shortened the regeneration time. On the 28th day of culture, the positive effect of magnetic field on plant fresh weight, length, number of leaves and chlorophyll content in node explants of P. tomentosa and P. fortunei was observed. It was found that this effect varied with exposure time. When the cultures were exposed to a magnetic field with strength of 2.9–4.8 mT for 19.8 s, the regenerated P. tomentosa and P. fortunei plants dominated the control plants.