A Lichenological Excursion to the West of Scotland

ABSTRACT

Background: Hybridisation can be a threat for the survival of a rare species because, in the case of insufficient numbers of appropriate mates, a rare form is much more likely to cross with a widespread taxon.

Aims: In the present study, we tested hypotheses concerning the level of hybridisation between endangered Betula humilis and its widespread congeners: B. pendula and B. pubescens as a function of habitat conditions.

Methods: We genotyped 312 individuals of three species using AFLP markers. B. humilis specimens were sampled in populations with low and high groundwater levels. Morphological identification of B. pubescens and B. pendula was verified using the Atkinson discriminant function.

Results: Altogether, 15 individuals (4.8%) were indicated as putative hybrids. The B. humilis hybrids were found in dry habitats and they could be classified as F1 or F2 generation. Tree hybrids could represent backcrosses to either B. pendula or B. pubescens.

Conclusions: Genetic analyses contradicted the idea that hybridisation between B. humilis and its close relatives was extensive. On the other hand, the presence of introgressed individuals in the populations in areas with low groundwater levels implied that pollen swamping might be a threat for declining B. humilis stands.     

Novelties in spermacoceae (Rubiaceae) from Bolivia and Paraguay

One new Bolivian species (Borreria pazensis) and three new varieties (Borreria densiflora var.minima, Richardia, scabra var.chacoensis andStaelia virgata var.killeenii) are described and illustrated. The genusDiodella, with three species (D. apiculata comb. nov., D. radula comb. nov., andD. teres), is reported for the first time.Borreria limae, B. wunschmannii, B. scabiosoides var.scabiosoides, andB. scabiosoides var.anderssonii are also reported as new to Bolivia.     

Two new species of Blechnum (Blechnaceae) from the neotropics

Blechnum moranianum is a new species similar toB. loxense, andB. nigrum is segregated from theB. fragile complex. Both are described and illustrated as result of the author's taxonomic fern work in Costa Rica. Blechnum moranianum es una especie nueva similar aB. loxense, yB. nigrum es segregada del complejoB. fragile. Ambas son aquí descritas e ilustradas como resultado de los trabajos taxonómicos del autor en los helechos de Costa Rica.     

基于可培养方法分析云南腾冲小空山火山谷芽胞杆菌分布特征

【目的】为了解云南腾冲小空山火山谷土壤中可培养芽胞杆菌种类分布特征。【方法】采用可培养手段对小空山火山谷阳坡、谷底和阴坡土壤中的芽胞杆菌进行分离培养,根据16S rRNA基因序列同源性对分离菌株进行鉴定,并分析系统发育地位。利用Canoco5软件分析采样点芽胞杆菌种类分布特征与土壤样品理化性质的相关性。【结果】从火山谷土壤样品中共分离获得180株芽胞杆菌,16S rRNA基因测序鉴定结果表明分离菌株隶属于芽胞杆菌纲2个科(芽胞杆菌科和类芽胞杆菌科)、6个属、34个种,其中芽胞杆菌属(Bacillus) 11个种,类芽胞杆菌属(Paenibacillus) 14个种,短芽胞杆菌属(Brevibacillus)3个种,赖氨酸芽胞杆菌属(Lysinibacillus)4个种,嗜冷芽胞杆菌属(Psychrobacillus)1个种和绿芽胞杆菌属(Viridibacillus)2个种,其中7个菌株与其最近模式菌株16SrRNA相似性低于种的界定阈值(98.65%),为芽胞杆菌潜在新物种。优势属为芽胞杆菌属和类芽胞杆菌属,优势种为蕈状芽胞杆菌(Bacillusmycoides),图瓦永芽胞杆菌(Bacillustoyonensis),蜡状芽胞杆菌(Bacilluscereus),解木糖赖氨酸芽胞杆菌(Lysinibacillusxylanilyticus),蜂房类芽胞杆菌(Paenibacillusalvei)和沙地绿芽胞杆菌(Viridibacillus arenosi)。其中16个种分离自阳坡,29个种分离自阴坡,9个种分离自谷底,三者共同种类为6种。阳坡、谷底和阴坡的芽胞杆菌种群分布Bray-Curtis相似性为62.4%,多样性分析结果表明,Shannon指数(H′)大小次序为阴坡阳坡谷底。环境因子分析发现,芽胞杆菌种群分布多样性特征与其土壤的海拔高度、碳氮比和硫含量呈负相关,而和碳源和氮源含量呈正相关。【结论】从以上结果得出,云南腾冲火山谷有着较为丰富的芽胞杆菌资源,且还存在可分离培养的芽胞杆菌的潜在新物种,为利用火山微生物资源提供了保障。     

镉胁迫对2种油菜土壤真菌群落的影响

[背景] 人类活动引起的农田重金属污染已成为严重的环境问题。镉（Cd）是最具毒性的重金属之一,能对人体和生态系统构成威胁。[目的] 研究不同浓度镉处理对2种油菜（甘蓝型油菜和芥菜型油菜）的土壤（根际和非根际）真菌群落的影响,为镉的生物修复和健康风险评估提供理论基础。[方法] 对2种油菜土壤（根际和非根际）真菌转录间隔区（Internal Transcribed Spacer,ITS）进行高通量测序,分析镉对根际和非根际土壤真菌群落的影响。[结果] 镉胁迫改变了土壤真菌群落的组成和结构,但对2种油菜土壤真菌群落的α多样性几乎无显著影响。土壤镉浓度和生物量与2种油菜根际土壤真菌群落显著相关,芥菜型油菜非根际土壤真菌群落也与镉污染浓度显著相关。土壤真菌分子生态网络也受到镉污染的影响,甘蓝型油菜根际土壤网络稳定性降低,共生关系减少。甘蓝型油菜非根际土壤网络稳定性升高,但共生关系减少。芥菜型油菜的根际和非根际土壤的网络稳定性升高,而且共生关系增多。[结论] 镉污染会影响土壤系统中的本土真菌群落,从而可能进一步改变土壤的生态系统功能。     

杜比亚蟑螂肠道菌的分离鉴定及产消化酶功能菌株的筛选

【背景】杜比亚蟑螂(Blaptica dubia)可用于活体饲料、化妆品和医药保健品的生产,其肠道菌的研究对杜比亚蟑螂的饲养和肠道菌资源的开发与利用都十分重要。【目的】揭示杜比亚蟑螂肠道可培养菌的种类,筛选具有产消化酶功能的菌株,为理解肠道菌对宿主的影响机理及功能菌株的利用提供科学依据和研究材料。【方法】采用体外培养法获得杜比亚蟑螂肠道菌,结合形态学和分子生物学方法进行鉴定;用水解圈法分别筛选产纤维素酶、蛋白酶、脂肪酶和淀粉酶菌株。【结果】在杜比亚蟑螂肠道中共分离出4属7种细菌,其中芽孢杆菌属(Bacillus)2种,沙雷氏菌属(Serratia)和柠檬酸杆菌属(Citrobacter)各2种,肠球菌属(Enterococcus)1种。从获得的20个菌株中筛选出10个具有产消化酶功能的菌株。其中,芽孢杆菌属的菌株D6、D12和D20具有产纤维素酶、蛋白酶、淀粉酶及脂肪酶4种消化酶的功能;沙雷氏菌属的菌株D3、D7、D9、D11和D15具有产纤维素酶、蛋白酶和脂肪酶3种消化酶的能力;柠檬酸杆菌属的菌株D5具有产纤维素酶的功能;肠球菌属的菌株D17具有产蛋白酶的能力。【结论】杜比亚蟑螂肠道多种细菌具有产消化酶帮助降解大分子营养物质的功能,可通过协助食物消化影响宿主健康。菌株D12、D7和D11分别具有最强产纤维素酶、蛋白酶和脂肪酶的能力,是可进一步开发利用的肠道功能菌株资源。     

Bryobartramia schelpei T.A.Hedderson,a new species to accommodate the South African populations of the genus

Abstract

South African populations of Bryobartramia have been treated as B. novae-valesiae, a species otherwise restricted to Australia. However, material from the two regions differs in a number of traits, and the African populations are here described as a new species, B. schelpei. The Cape species differs most obviously from B. novae-valesiae in the markedly prorate-papillose, narrow, thick-walled cells of the calyptra. Nested analysis of variance reveals further morphometric differences, including the relatively narrower, more cylindrical, calyptra with a longer rostrum, and the smaller leaf cells and spores. Bryobartramia schelpii is known only from arid portions of the winter rainfall region in the Northern and Western Cape Provinces of South Africa.     

Differences in investment and functioning of cluster roots account for different distributions of Banksia attenuata and B. sessilis,with contrasting life history

Aims

Banksia attenuata is a resprouting species growing in deep sand, while B. sessilis is a fire-killed species occurring in shallow sand over laterite or limestone. We aimed to discover the ecophysiological basis for their different distributions by exploring their investment in deep non-cluster roots and shallow cluster roots, and their cluster-root functioning.

Methods

Deep-pot (1 m), shallow-pot (400 mm), hydroponic experiments and phosphorus (P)-extraction experiment were carried out. Biomass allocation, cluster-root exudation, plant P and leaf manganese (Mn) concentrations were measured.

Results

Banksia attenuata allocated more biomass to deep roots and less biomass to cluster roots than B. sessilis did in deep pots. The two Banksias released similar carboxylates in all experiments, with similar carboxylate-exudation rates in hydroponics. The carboxylate amount per unit cluster root of B. sessilis grown in shallow pots was greater than that of B. attenuata, and B, sessilis acquired more P than B. attenuata did in limestone substrate.

Conclusions

Greater investment in deep roots for water uptake accounts for the presence of B. attenuata in deep sand, and vice versa for the absence of B. sessilis. A larger investment in cluster roots, which released greater amounts of carboxylates, likely accounts for B. sessilis occurring over limestone. Trade-offs in investment and cluster-root functioning support the species’ distribution patterns and life histories. Leaf Mn concentration was a good proxy for the plant capacity to acquire P.

     

日化产品中洋葱伯克霍尔德氏菌复合群(Bcc)的分类和神秘伯克霍尔德氏菌的耐药性研究

【目的】对从2020–2022年不同日化产品中分离的29株洋葱伯克霍尔德氏菌复合群(Burkholderia cepacia complex,Bcc)进行分类和分型,另将2020年前来源于日化产品中6株被鉴定为Burkholderia lata的菌株进行分类更正。探究神秘伯克霍尔德氏菌(Burkholderia aenigmatica)的耐药性。【方法】本文主要应用多位点分型研究方法(multilocus sequence typing,MLST),PCR扩增atpD、gltB、gyrB、recA、lepA、phaC和trp B 7个管家基因片段,将测序结果与MLST数据库中的数据比对分析,获得菌株各管家基因的编号和ST型(sequence type),对本检测中心分离自日化产品的Bcc进行分型;利用多位点序列分析(multilocus sequence analysis,MLSA),结合MLST中等位基因的核苷酸序列构建进化树,从而对Bcc进行系统发育分析和鉴定。利用最小抑菌浓度法(minimum inhibitory concentration,MIC)测定Bcc对常见防腐剂(1,...     

蝇蛹俑小蜂对橘小实蝇和瓜实蝇的偏好性

【背景】蝇蛹俑小蜂是实蝇类害虫蛹期的一种重要寄生蜂,对压制下一代实蝇类害虫的种群数量具有重要作用,但有关其对不同实蝇害虫的寄生特性尚缺乏研究。【方法】采用"H"型装置和培养皿测定方法,研究了蝇蛹俑小蜂的寄主选择偏好性。【结果】蝇蛹俑小蜂在橘小实蝇蛹和瓜实蝇蛹共存的情况下,偏好在橘小实蝇蛹上停留,且寄生率较高,最高寄生率达61.11%。【结论与意义】本研究为合理利用蝇蛹俑小蜂控制实蝇类害虫提供了理论基础。     

A Bryophyte Flora of Hertfordshire

Abstract

A new species, Bruchia queenslandica, collected in tropical Australia, is described. It is similar to B. carolinae in spore features but differs in the smooth calyptra and in vegetative characters. It is compared with B. carolinae and B. brevipes     

Novelties in Begonia (Begoniaceae) from the coastal forests of Brazil

Two new narrow endemic species ofBegonia from the Atlantic coastal forests of Brazil,B. espiritosantensis andB. ibitiocensis, are described and illustrated.Begonia schenkii var.calvescens, an endemic taxon from the states of Santa Catarina and Rio Grande do Sul, is transferred to species rank, and described and illustrated. A distribution map is provided for all three taxa.     

Notes on British Boleti: II.

Summary

A key to the species of the genus Boletus sensu stricto based on habitat, microscopic and macroscopic characters is proposed. Three extra-limital species, as yet unrecorded from the British Isles, B. torosus, B. lupinus Krombh. and B. lupinus s. Bres., are included in the key in the hope that they may appear in future. They may have been overlooked previously or confused with far commoner forms, especially B. luridus, to which many quite distinct species have previously been referred. Also included in the key are three boletes not considered taxonomically to belong to this genus in its strict sense, although in some ways they are superficially similar. The only West European species of Tylopilus is keyed out and its taxonomic position considered. Boletus rubellus Krombh. placed by some American authors in Boletus sensu stricto is also discussed.     

Cytogenetics of Batrachyla species (Anura: Neobatrachia: Ceratophryidae) of southern South America,with phylogenetics comments

Abstract

A comparative cytogenetic analysis showed that B. antartandica, B. leptopus, B. nibaldoi and B. taeniata share the same diploid number 2n = 26, but not the same fundamental number (FN), which was 52 in B. leptopus and 50 in the other three species. The karyotype of B. nibaldoi, including C‐band patterns and locations of the NORs, are described for the first time. The C‐band patterns were species‐specific and were helpful in distinguishing taxa. Batrachyla leptopus can be distinguished from its congeners by the absence of telocentric chromosomes and by secondary constrictions in the long arms of pair 6 and short arms of pairs 7 and 11. The chromosomal data suggest that Batrachyla might be a paraphyletic genus.     

An extinct species of Basella: pollen evidence from sediments (~80 ka) in Kerala,India

Abstract

The genus Basella belongs to family Basellaceae and is comprised of five species. Out of these, Basella alba is pantropical in distribution, B. paniculata is endemic to south-eastern Africa and the other three species viz. B. excavata, B. leandriana and B. madagascariensis are endemic to Madagascar. The palynological study of an organic layer buried ~80 ka in Chaganacherry, Kerala revealed a rich diversity of rainforest pollen and estuarine/marine palynomorphs indicating warm and humid climate coupled with sea level high stand. The Basella pollen recorded from this sediment shows intermediate characters of two extant Basella species. While it resembles B. paniculata in being pantocolpate (20), it shows affinity with B. alba in sexine characters. The recovered pollen was therefore, ascertained to be a new species, named here as B. keralensis sp. nov. The age correlation of the studied sediment was carried out by fingerprinting (Rare Earth Elements) of Youngest Toba Tuff (YTT) (glass shards) which spread in the atmosphere through a volcanic eruption in Sumatra ~74 ka and also with marine palynomorph markers correlating the interglacial Marine Isotopic Stage 5a (~80 ka). It is inferred that earlier, the genus Basella comprised of six species out of which Basella keralensis sp. nov. became extinct and until now neither the fossil record nor the extant form of this is known in records from any part of the World.