Comparative FISH and molecular identification of new stripe rust resistant wheat-Thinopyrum intermedium ssp. trichophorum introgression lines

Thinopyrum intermedium(2 n = 6 x = 42, JJJ^sJ^sStSt) has been hybridized extensively with common wheat and has proven to be a valuable germplasm source for improving disease resistance, quality attributes, and yield potential in wheat. We characterized new disease resistant wheat-Th. intermedium derivatives A1082 and A5-5 using sequential multi-color fluorescence in situ hybridization(mc-FISH), genomic in situ hybridization(GISH), PCRbased landmark unique gene(PLUG) and intron targeting(IT) markers. A1082 was identified as a wheat-Th. intermedium 3J disomic addition line, and A5-5 was a T4BS·5J^sL homozygous Robertsonian translocation line. Seventy-one and 106 pairs of primers amplified Th.intermedium-specific bands allowing chromosomes 3J and 5J^s to be tracked, respectively. A new oligonucleotide probe, Oligo-6 H-2-100, was developed for FISH labeling of the subterminal region of the long arm of chromosome 5J^s. Both lines were highly resistant to stripe rust pathogen races prevalent in Chinese field screening nurseries. A5-5 also displayed a significant increase in tiller number compared to its wheat parent. The new lines can be exploited as useful germplasms for wheat improvement.

Breeding biology of the Green-backed Tit(Parus monticolus)in southwest China

Studies on breeding biology enable us to broaden our understanding of the evolution of life history strategies.We studied the breeding biology of the Green-backed Tit(Parus monticolus)to provide comprehensive data on nest and egg characteristics,parental behavior throughout egg laying and nestling periods,and reproductive outcome.Our study reveals adaptive behavioral patterns and reproductive strategies for P.monticolus.

Breeding ecology of two sympatric laughingthrushes(Trochalopteron milnei and Garrulax berthemyi)in southwestern China

Here we documented up-to-date information on breeding ecology of Buffy Laughingthrush(Garrulax berthemyi),an endemic species of China,and a sympatric coordinal Red-tailed Laughingthrush(Trochalopteron milnei),in southwestern China.Furthermore,we compared breeding ecology of these two sympatric species.No significant differences were found in clutch size,egg size,nest size,nest height,nest habitat and predation rate between these two species except nests depth,nests cover and eggs color.The Red-tailed Laughingthrush nestlings differed from those of the Buffy Laughingthrush in gape morphology and the extent of down.Observation of breeding behavior showed that cooperative breeding might exist in the population of Buffy Laughingthrush.

Novel expressed sequence tags of an alpine-cold plant species,Gymnadenia conopsea (Orchidaceae)

Gymnadenia conopsea,an alpine Orchidaceae plant,was one of the widely used Tibetan traditional medicines.In this study,we sequenced total 105 expressed sequence tags (ESTs) from a full-length cDNA expression library constructed by the Oligo-capping technique.The further bioinformatic analyses suggested that the 65 represented unique sequences showed high homology to previously identified genes in other plants:30 sequences matched to other uncharacterized expressed sequence tags (ESTs),and 10 sequences showed no good matches to available sequences in DNA databases.Gene ontology annotation by InterProScan indicated that many of these cDNAs (7 percent) have no known molecular functions and may be unique to G.conopsea.Fifty-five ESTs with matched proteins were involved in a series of diverse functions,in which molecular function such as 'binding' (42.9 percent) and 'catalytic activity' (25.0 percent) were the most frequent functions of the cDNAs.This cDNA library provided a critical basis for further investigation of functional genes expression under cold stress in this alpine species.In addition,13 ESTs-based polymerase chain reaction (PCR) primers were designed and can also be used for genotypic identification and for the genetic diversity analysis of G.conopsea and its closely related species.

New PCR based markers allowed to identify Secale chromatin in wheat-Secale africanum introgression lines

The genus of Secale has many agronomically important characters.In order to use the best of this species,markers tracking the rye chromatin incorporated into wheat must be developed.In this study,one rye genome-specific random amplified polymorphic DNA(RAPD)marker was isolated from Secale africanum(Ra genome).Two cloned markers,named OPP13_(1165) and OPP13_(662),were 1165 bp and 662 bp,respectively.Sequence analysis revealed that OPP13_(1165) was highly homologous to a part of a new class of transposon-like gene called the Revolver family,and OPP13_(662) was partially similar to LTR gypsy-like retrotransposon.Fluorescence in situ hybridization(FISH)showed only OPP13_(1165) localized within the whole arms of rye except their terminal regions and no signal was detected on wheat chromosomes,while OPP13_(662) had no hybridization signal detected on wheat and rye genomes.Based on these sequences,two pairs of sequence-characterized amplified region(SCAR)primers were designed,and the resulted SCAR markers were able to target both cultivated and wild Secale species.The FISH patterns and the two SCAR markers should be able to identify and track all wheat-rye translocation lines,especially the S.africanum chromatin.

Egg rejection based on egg size recognition as a specific strategy against parasitic cuckoos

In the coevolutionary interactions between avian brood parasites and their hosts,egg recognition based on color and/or pattern is a common and effective defense to counter parasitism.However,for egg recognition based on size,only a few studies have found affirmative results,and they do not provide unambiguous evidence that egg size recognition in hosts has evolved as an important and specific anti-parasite adaptation against parasite eggs.We studied the brood parasite system between the Asian emerald cuckoo Chrysococcyx maculatus and its host,the chestnut-crowned warbler Phylloscopus castaniceps.The cuckoo parasitizes the warbler using non-mimetic and larger eggs at a parasitism rate of 12.9%.The warbler nests used in this experiment were built in a dark environment with the nest illuminance near 0 lux.Experiments with 2 types of model eggs with colors and patterns resembling cuckoo eggs of different sizes(cuckoo egg size or host egg size)showed that the warblers were able to reject 63.6%of cuckoo model eggs under these dim light conditions.However,model eggs with the same color and pattern similar to the warbler egg size were always accepted.This study provides strong evidence supporting the theory that egg size recognition can be evolved in hosts as a specific anti-parasite adaptation against cuckoos.We suggest that the egg size recognition of the warbler is an outcome of the tradeoff between the costs of violating the parental investment rule and suffering cuckoo parasitism.

Genome sequencing of Sitopsis species provides insights into their contribution to the B subgenome of bread wheat

Wheat(Triticum aestivum,BBAADD)is an allohexaploid species that originated from two polyploidization events.The progenitors of the A and D subgenomes have been identified as Triticum urartu and Aegilops tauschii,respectively.Current research suggests that Aegilops speltoides is the closest but not the direct ancestor of the B subgenome.However,whether Ae.speltoides has contributed genomically to the wheat B subgenome and which chromosome regions are conserved between Ae.speltoides and the B subgenome remain unclear.Here,we assembled a high-quality reference genome for Ae.speltoides,resequenced 53 accessions from seven species(Aegilops bicornis,Aegilops longissima,Aegilops searsii,Aegilops sharonensis,Ae.speltoides,Aegilops mutica[syn.Amblyopyrum muticum],and Triticumdicoccoides)and revealed their genomic contributions to the wheat B subgenome.Our results showed that centromeric regions were particularly conserved between Aegilops and Triticum and revealed 0.17 Gb of conserved blocks between Ae.speltoides and the B subgenome.We classified five groups of conserved and non-conserved genes between Aegilops and Triticum,revealing their biological characteristics,differentiation in gene expression patterns,and collinear relationships between Ae.speltoides and the wheat B subgenome.We also identified gene families that expanded in Ae.speltoides during its evolution and 789 genes specific to Ae.speltoides.These genes can serve as genetic resources for improvement of adaptability to biotic and abiotic stress.The newly constructed reference genome and large-scale resequencing data for Sitopsis species will provide a valuable genomic resource for wheat genetic improvement and genomic studies.

贵州麻阳河国家级自然保护区红外相机鸟兽监测

为进一步查清贵州麻阳河国家级自然保护区鸟兽多样性,丰富生物编目,我们于2018年7月至2019年8月利用红外相机进行公里网格全境布设监测。共记录兽类5目10科18属20种、鸟类7目18科34属42种,其中新增保护区记录11种,记录国家I级重点保护野生动物2种,分别是黑叶猴(Trachypithecusfrancoisi)和白颈长尾雉(Syrmaticus ellioti),国家II级重点保护野生动物大灵猫(Viverra zibetha)、白冠长尾雉(Syrmaticus reevesii)等7种。相对多度指数计算结果表明,小麂(Muntiacus reevesi)、猪獾(Arctonyx collaris)和野猪(Sus scrofa)是该区域内常见兽类,而地栖雉类则以红腹锦鸡(Chrysolophus pictus)和灰胸竹鸡(Bambusicola thoracicus)为主。分时段的相对多度指标表明,小麂在6:00–15:00和17:00–21:00两个时段均保持活跃,猪獾则偏好5:00–6:00和19:00–23:00活动,野猪在6:00–7:00最为活跃,红腹锦鸡活动高峰在12:00–13:00,而灰胸竹鸡的活动高峰分别为14:00–15:00和16:00–17:00。在物种丰度上,单个相机位点的平均拍摄物种数显示,在缓冲区、灌丛及针阔混交林以及800–1,200 m海拔段上物种较多。监测结果有利于进一步掌握此区域的动物多样性资源并促进资源的保护与管理。

Understanding of degradation-resistant behavior of nanostructured thermal barrier coatings with bimodal structure

Nanostructured thermal barrier coatings(TBCs) often provide high degradation resistance, as well as extended lifetime. However, the underlying mechanism has not been fully understood. In this study, the sintering characteristics of nanostructured yttria-stabilized zirconia(YSZ) coatings were investigated,and compared with those of the conventional YSZ coatings. Multiscale characterizations of the changes in microstructures and properties were performed. Results showed that the enhanced high-performance durability was mainly attributed to different sintering mechanisms of lamellar zones and nanozones.Sintering characteristics of the lamellar zones were similar to those of the conventional coatings. Stagesensitive healing of two-dimensional(2 D) pores dominated the sintering behavior of the lamellar zones.However, the differential densification rates between nanozones and lamellar zones of the nanostructured TBCs led to the formation of coarse voids. This counteractive effect, against healing of 2 D pores, was the main factor contributing to the retardation of the performance degradation of bimodal TBCs during thermal exposure. Based on the understanding of the performance-degradation resistance, an outlook towards TBCs with higher performances was presented.

Corrigendum to"Understanding of degradation-resistant behavior of nanostructured thermal barrier coatings with bimodal structure"[J.Mater.Sci.Technol.35(2019)231-238]

The authors regret to inform that(i)a wrong Table 1 was uploaded,and a corrected one was show below;(ii)a reference label is missing in caption of Fig.8(A),and it should be:Fig.8.Interfacial evolution between nanozones and lamellar zones during thermal exposure:(A)as-deposited state[45];(B)20 h;(C)500 h;(iii)a wrong figure was uploaded in Fig.2(A,0 h),and a revised one is shown below.

Dynamic-stiffening-induced aggravated cracking behavior driven by metal-substrate-constraint in a coating/substrate system

Air plasma sprayed thermal barrier coatings(APS-TBCs)saw their wide application in high-temperaturerelated cutting-edge fields.The lamellar structure of APS-TBCs provides a significant advantage on thermal insulation.However,short life span is a major headache for APS-TBCs.This is highly related to the property changes and passive behaviors of the coatings during thermal service.Herein,a finite element model was developed to investigate the dynamic stiffening and substrate constraint on total spallation process.Results show that the stiffening accelerates the crack propagation of APS-TBCs.The driving force for crack propagation,which is characterized by strain energy release rate(SERR),is significantly enlarged.Consequently,the crack starts to propagate when the SERR exceeds the fracture toughness.In addition,the changing trends of SERR and crack propagation features are highly associated with temperatures.A higher temperature corresponds to more significant effect of stiffening on substrate constraint.In brief,temperature-dependent stiffening significantly aggravates the substrate constraint effect on APS-TBCs,which is one of the major causes for the spallation.Given that,lowering stiffening degree is essential to maintain high strain tolerance,and to further extend the life span of APS-TBCs.This understanding contributes to the development of advanced TBCs in future applications.